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Abstract
Microglia are subject to change in tandem with the endogenously generated biological oscillations known as our circadian rhythm. Studies have shown microglia harbor an intrinsic molecular clock which regulates diurnal changes in morphology and influences inflammatory responses. In the adult brain, microglia play an important role in the regulation of condensed extracellular matrix structures called perineuronal nets (PNNs), and it has been suggested that PNNs are also regulated in a circadian and diurnal manner. We sought to determine whether microglia mediate the diurnal regulation of PNNs via CSF1R inhibitor dependent microglial depletion in C57BL/6J mice, and how the absence of microglia might affect cortical diurnal gene expression rhythms. While we observe diurnal differences in microglial morphology, where microglia are most ramified at the onset of the dark phase, we do not find diurnal differences in PNN intensity. However, PNN intensity increases across many brain regions in the absence of microglia, supporting a role for microglia in the regulation of PNNs. Here, we also show that cortical diurnal gene expression rhythms are intact, with no cycling gene changes without microglia. These findings demonstrate a role for microglia in the maintenance of PNNs, but not in the maintenance of diurnal rhythms.
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Affiliation(s)
- Rocio A Barahona
- Department of Neurobiology and Behavior, University of California, 3208 Biological Sciences III, Irvine, CA, 92697, USA
| | - Samuel Morabito
- Mathematical, Computational and Systems Biology (MCSB) Program, University of California, Irvine, CA, USA
| | - Vivek Swarup
- Department of Neurobiology and Behavior, University of California, 3208 Biological Sciences III, Irvine, CA, 92697, USA
| | - Kim N Green
- Department of Neurobiology and Behavior, University of California, 3208 Biological Sciences III, Irvine, CA, 92697, USA.
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Wei L, Xue Z, Lan B, Yuan S, Li Y, Guo C, Zhang R, Ding R, Shen H. Arctigenin Exerts Neuroprotective Effect by Ameliorating Cortical Activities in Experimental Autoimmune Encephalomyelitis In Vivo. Front Immunol 2021; 12:691590. [PMID: 34349758 PMCID: PMC8327179 DOI: 10.3389/fimmu.2021.691590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/01/2021] [Indexed: 11/19/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic disease in the central nervous system (CNS), characterized by inflammatory cells that invade into the brain and the spinal cord. Among a bulk of different MS models, the most widely used and best understood rodent model is experimental autoimmune encephalomyelitis (EAE). Arctigenin, a botanical extract from Arctium lappa, is reported to exhibit pharmacological properties, including anti-inflammation and neuroprotection. However, the effects of arctigenin on neural activity attacked by inflammation in MS are still unclear. Here, we use two-photon calcium imaging to observe the activity of somatosensory cortex neurons in awake EAE mice in vivo and found added hyperactive cells, calcium influx, network connectivity, and synchronization, mainly at preclinical stage of EAE model. Besides, more silent cells and decreased calcium influx and reduced network synchronization accompanied by a compensatory rise in functional connectivity are found at the remission stage. Arctigenin treatment not only restricts inordinate individually neural spiking, calcium influx, and network activity at preclinical stage but also restores neuronal activity and communication at remission stage. In addition, we confirm that the frequency of AMPA receptor-mediated spontaneous excitatory postsynaptic current (sEPSC) is also increased at preclinical stage and can be blunted by arctigenin. These findings suggest that excitotoxicity characterized by calcium influx is involved in EAE at preclinical stage. What is more, arctigenin exerts neuroprotective effect by limiting hyperactivity at preclinical stage and ameliorates EAE symptoms, indicating that arctigenin could be a potential therapeutic drug for neuroprotection in MS-related neuropsychological disorders.
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Affiliation(s)
- Liangpeng Wei
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
| | - Zhenyi Xue
- Department of Immunology, Key Laboratory of Immune Microenvironment and Diseases of Educational Ministry of China, Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, Tianjin, China
| | - Baihui Lan
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
| | - Shiyang Yuan
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
| | - Yuanyuan Li
- Innovation Institute of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Cunle Guo
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
| | - Rongxin Zhang
- Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
| | - Ran Ding
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Hui Shen
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
- Research Institute of Neurology, General Hospital, Tianjin Medical University, Tianjin, China
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Veverka T, Hluštík P, Otruba P, Hok P, Opavský R, Zapletalová J, Kaňovský P. Cortical somatosensory processing after botulinum toxin therapy in post-stroke spasticity. Medicine (Baltimore) 2021; 100:e26356. [PMID: 34160405 PMCID: PMC8238289 DOI: 10.1097/md.0000000000026356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 06/01/2021] [Indexed: 01/04/2023] Open
Abstract
In dystonic and spastic movement disorders, abnormalities of motor control and somatosensory processing as well as cortical modulations associated with clinical improvement after botulinum toxin A (BoNT-A) treatment have been reported, but electrophysiological evidence remains controversial. In the present observational study, we aimed to uncover central correlates of post-stroke spasticity (PSS) and BoNT-A-related changes in the sensorimotor cortex by investigating the cortical components of somatosensory evoked potentials (SEPs). Thirty-one chronic stroke patients with PSS of the upper limb were treated with BoNT-A application into the affected muscles and physiotherapy. Clinical and electrophysiological evaluations were performed just before BoNT-A application (W0), then 4 weeks (W4) and 11 weeks (W11) later. PSS was evaluated with the modified Ashworth scale (MAS). Median nerve SEPs were examined in both upper limbs with subsequent statistical analysis of the peak-to-peak amplitudes of precentral P22/N30 and postcentral N20/P23 components. At baseline (W0), postcentral SEPs were significantly lower over the affected cortex. At follow up, cortical SEPs did not show any significant changes attributable to BoNT-A and/or physiotherapy, despite clear clinical improvement. Our results imply that conventional SEPs are of limited value in evaluating cortical changes after BoNT-A treatment and further studies are needed to elucidate its central actions.
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Affiliation(s)
- Tomáš Veverka
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
| | - Petr Hluštík
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
| | - Pavel Otruba
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
| | - Pavel Hok
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
| | - Robert Opavský
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
| | - Jana Zapletalová
- Department of Biophysics, Biometry and Statistics, Palacký University Olomouc, Czechia
| | - Petr Kaňovský
- Department of Neurology, Palacký University Olomouc and University Hospital Olomouc
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Alipio JB, Haga C, Fox ME, Arakawa K, Balaji R, Cramer N, Lobo MK, Keller A. Perinatal Fentanyl Exposure Leads to Long-Lasting Impairments in Somatosensory Circuit Function and Behavior. J Neurosci 2021; 41:3400-3417. [PMID: 33853934 PMCID: PMC8051687 DOI: 10.1523/jneurosci.2470-20.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/07/2020] [Accepted: 12/30/2020] [Indexed: 11/21/2022] Open
Abstract
One consequence of the opioid epidemic are lasting neurodevelopmental sequelae afflicting adolescents exposed to opioids in the womb. A translationally relevant and developmentally accurate preclinical model is needed to understand the behavioral, circuit, network, and molecular abnormalities resulting from this exposure. By employing a novel preclinical model of perinatal fentanyl exposure, our data reveal that fentanyl has several dose-dependent, developmental consequences to somatosensory function and behavior. Newborn male and female mice exhibit signs of withdrawal and sensory-related deficits that extend at least to adolescence. As fentanyl exposure does not affect dams' health or maternal behavior, these effects result from the direct actions of perinatal fentanyl on the pups' developing brain. At adolescence, exposed mice exhibit reduced adaptation to sensory stimuli, and a corresponding impairment in primary somatosensory (S1) function. In vitro electrophysiology demonstrates a long-lasting reduction in S1 synaptic excitation, evidenced by decreases in release probability, NMDA receptor-mediated postsynaptic currents, and frequency of miniature excitatory postsynaptic currents (mEPSCs), as well as increased frequency of miniature inhibitory postsynaptic currents (mIPSCs). In contrast, anterior cingulate cortical neurons exhibit an opposite phenotype, with increased synaptic excitation. Consistent with these changes, electrocorticograms (ECoGs) reveal suppressed ketamine-evoked γ oscillations. Morphologic analysis of S1 pyramidal neurons indicate reduced dendritic complexity, dendritic length, and soma size. Further, exposed mice exhibited abnormal cortical mRNA expression of key receptors involved in synaptic transmission and neuronal growth and development, changes that were consistent with the electrophysiological and morphologic changes. These findings demonstrate the lasting sequelae of perinatal fentanyl exposure on sensory processing and function.SIGNIFICANCE STATEMENT This is the first study to show that exposure to fentanyl in the womb results in behavioral, circuitry, and synaptic effects that last at least to adolescence. We also show, for the first time, that this exposure has different, lasting effects on synapses in different cortical areas.
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Affiliation(s)
- Jason B Alipio
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Catherine Haga
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Megan E Fox
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Keiko Arakawa
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Rakshita Balaji
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Nathan Cramer
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Mary Kay Lobo
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Asaf Keller
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
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Rotondo EK, Bieszczad KM. Sensory cortical and subcortical auditory neurophysiological changes predict cue-specific extinction behavior enabled by the pharmacological inhibition of an epigenetic regulator during memory formation. Brain Res Bull 2021; 169:167-183. [PMID: 33515653 PMCID: PMC8591994 DOI: 10.1016/j.brainresbull.2021.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/03/2021] [Accepted: 01/22/2021] [Indexed: 11/19/2022]
Abstract
Extinction learning and memory have been broadly investigated at both behavioral and neural levels, but sensory system contributions to extinction processes have been less explored. Using a sound-reward extinction paradigm in male rats, we reveal both cortical and subcortical forms of plasticity associated with the cue-specificity of behavioral extinction memory. In the auditory cortex, frequency tuning narrowed by up to two-thirds of an octave around the remembered extinguished sound cue. Subcortical signals revealed in the auditory brainstem response (ABR) in the same animals developed smaller amplitudes of some (but not all) ABR peaks evoked by the extinguished sound frequency. Interestingly, treatment with an inhibitor of histone deacetylase 3 (HDAC3-i) facilitated both auditory cortical tuning bandwidth changes and changes in subcortical peak amplitude evoked only by the extinguished sound frequency. These neurophysiological changes were correlated to each other, and to the highly precise extinction behavior enabled by HDAC3-i (compared to vehicle controls). Thus, we show for the first time that HDAC3 regulates the specificity of sensory features consolidated in extinction memory. Further, the sensory cortical changes in tuning bandwidth recapitulate known effects of blocking HDAC3 to enhance cue specificity in other behavioral tasks. Therefore, the findings demonstrate how some forms of sensory neuroplasticity may encode specific sensory features of learning experiences in order to enable cue-specific behaviors.
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Affiliation(s)
- Elena K Rotondo
- Dept. of Psychology, Rutgers- The State University of New Jersey, Piscataway, NJ, 08854, United States
| | - Kasia M Bieszczad
- Dept. of Psychology, Rutgers- The State University of New Jersey, Piscataway, NJ, 08854, United States.
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Abstract
Transcranial alternating current stimulation (tACS) modulates brain activity by passing electrical current through electrodes that are attached to the scalp. Because it is safe and noninvasive, tACS holds great promise as a tool for basic research and clinical treatment. However, little is known about how tACS ultimately influences neural activity. One hypothesis is that tACS affects neural responses directly, by producing electrical fields that interact with the brain’s endogenous electrical activity. By controlling the shape and location of these electric fields, one could target brain regions associated with particular behaviors or symptoms. However, an alternative hypothesis is that tACS affects neural activity indirectly, via peripheral sensory afferents. In particular, it has often been hypothesized that tACS acts on sensory fibers in the skin, which in turn provide rhythmic input to central neurons. In this case, there would be little possibility of targeted brain stimulation, as the regions modulated by tACS would depend entirely on the somatosensory pathways originating in the skin around the stimulating electrodes. Here, we directly test these competing hypotheses by recording single-unit activity in the hippocampus and visual cortex of alert monkeys receiving tACS. We find that tACS entrains neuronal activity in both regions, so that cells fire synchronously with the stimulation. Blocking somatosensory input with a topical anesthetic does not significantly alter these neural entrainment effects. These data are therefore consistent with the direct stimulation hypothesis and suggest that peripheral somatosensory stimulation is not required for tACS to entrain neurons. Transcranial alternating current stimulation (tACS) modulates brain activity by passing electrical current through electrodes that are attached to the scalp. However, whereas one hypothesis is that tACS affects neural responses directly, another is that tACS affects neural activity indirectly, via sensory fibers in the skin. This study demonstrates that tACS directly affects neurons within the brain, rather than relying on a peripheral route.
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Affiliation(s)
- Pedro G. Vieira
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Matthew R. Krause
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Christopher C. Pack
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- * E-mail:
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Shim H, Lee J, Kim S. BOLD fMRI and hemodynamic responses to somatosensory stimulation in anesthetized mice: spontaneous breathing vs. mechanical ventilation. NMR Biomed 2020; 33:e4311. [PMID: 32297409 PMCID: PMC7317444 DOI: 10.1002/nbm.4311] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/26/2020] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Mouse functional MRI (fMRI) has been of great interest due to the abundance of transgenic models. Due to a mouse's small size, spontaneous breathing has often been used. Because the vascular physiology affecting fMRI might not be controlled normally, its effects on functional responses were investigated with optical intrinsic signal (OIS) imaging and 9.4 T BOLD fMRI. Three conditions were tested in C57BL/6 mice: spontaneous breathing under ketamine and xylazine anesthesia (KX), mechanical ventilation under KX, and mechanical ventilation under isoflurane. Spontaneous breathing under KX induced an average pCO2 of 83 mmHg, whereas a mechanical ventilation condition achieved a pCO2 of 37-41 mmHg within a physiological range. The baseline diameter of arterial and venous vessels was only 7%-9% larger with spontaneous breathing than with mechanical ventilation under KX, but it was much smaller than that in normocapnic isoflurane-anesthetized mice. Three major functional studies were performed. First, CBV-weighted OIS and arterial dilations to 4-second forepaw stimulation were rapid and larger at normocapnia than hypercapnia under KX, but very small under isoflurane. Second, CBV-weighted OIS and arterial dilations by vasodilator acetazolamide were measured for investigating vascular reactivity and were larger in the normocapnic condition than in the hypercapnic condition under KX. Third, evoked OIS and BOLD fMRI responses in the contralateral mouse somatosensory cortex to 20-second forepaw stimulation were faster and larger in the mechanical ventilation than spontaneous breathing. BOLD fMRI peaked at the end of the 20-second stimulation under hypercapnic spontaneous breathing, and at ~9 seconds under mechanical ventilation. The peak amplitude of BOLD fMRI was 2.2% at hypercapnia and ~3.4% at normocapnia. Overall, spontaneous breathing induces sluggish reduced hemodynamic and fMRI responses, but it is still viable for KX anesthesia due to its simplicity, noninvasiveness, and well-localized BOLD activity in the somatosensory cortex.
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Affiliation(s)
- Hyun‐Ji Shim
- Center for Neuroscience Imaging Research (CNIR)Institute for Basic Science (IBS)Suwon16419Republic of Korea
- Department of Health Sciences and Technology, SAIHSTSungkyunkwan UniversitySeoul06355Republic of Korea
| | - Joonyeol Lee
- Center for Neuroscience Imaging Research (CNIR)Institute for Basic Science (IBS)Suwon16419Republic of Korea
- Department of Biomedical EngineeringSungkyunkwan UniversitySuwon16419Republic of Korea
| | - Seong‐Gi Kim
- Center for Neuroscience Imaging Research (CNIR)Institute for Basic Science (IBS)Suwon16419Republic of Korea
- Department of Health Sciences and Technology, SAIHSTSungkyunkwan UniversitySeoul06355Republic of Korea
- Department of Biomedical EngineeringSungkyunkwan UniversitySuwon16419Republic of Korea
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Vardar B, Güçlü B. Effects of basal forebrain stimulation on the vibrotactile responses of neurons from the hindpaw representation in the rat SI cortex. Brain Struct Funct 2020; 225:1761-1776. [PMID: 32495132 DOI: 10.1007/s00429-020-02091-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 05/13/2020] [Indexed: 11/28/2022]
Abstract
Basal forebrain (BF) cholinergic system is important for attention and modulates sensory processing. We focused on the hindpaw representation in rat primary somatosensory cortex (S1), which receives inputs related to mechanoreceptors identical to those in human glabrous skin. Spike data were recorded from S1 tactile neurons (n = 87) with (ON condition: 0.5-ms bipolar current pulses at 100 Hz; amplitude 50 μA, duration 0.5 s at each trial) and without (OFF condition) electrical stimulation of BF in anesthetized rats. We expected that prior activation of BF would induce changes in the vibrotactile responses of neurons during sinusoidal (5, 40, and 250 Hz) mechanical stimulation of the glabrous skin. The experiment consisted of sequential OFF-ON conditions in two-time blocks separated by 30 min to test possible remaining effects. Average firing rates (AFRs) and vector strengths of spike phases (VS) were analyzed for different neuron types [regular spiking (RS) and fast spiking (FS)] in different cortical layers (III-VI). Immediate effect of BF activation was only significant by increasing synchronization to 5-Hz vibrotactile stimulus within the second block. Regardless of frequency, ON-OFF paired VS differences were significantly higher in the second block compared to the first, more prominent for RS neurons, and in general for neurons in layers III and VI. No such effects could be found on AFRs. The results suggest that cholinergic activation induces some changes in the hindpaw area, enabling relatively higher increases in synchronization to vibrotactile inputs with subsequent BF modulation. In addition, this modulation depends on neuron type and layer, which may be related to detailed projection pattern from BF.
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Affiliation(s)
- Bige Vardar
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy, 34684, Istanbul, Turkey
| | - Burak Güçlü
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy, 34684, Istanbul, Turkey.
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Delatour LC, Yeh PWL, Yeh HH. Prenatal Exposure to Ethanol Alters Synaptic Activity in Layer V/VI Pyramidal Neurons of the Somatosensory Cortex. Cereb Cortex 2020; 30:1735-1751. [PMID: 31647550 PMCID: PMC7132917 DOI: 10.1093/cercor/bhz199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/04/2019] [Accepted: 08/04/2019] [Indexed: 12/31/2022] Open
Abstract
Fetal alcohol spectrum disorder (FASD) encompasses a range of cognitive and behavioral deficits, with aberrances in the function of cerebral cortical pyramidal neurons implicated in its pathology. However, the mechanisms underlying these aberrances, including whether they persist well beyond ethanol exposure in utero, remain to be explored. We addressed these issues by employing a mouse model of FASD in which pregnant mice were exposed to binge-type ethanol from embryonic day 13.5 through 16.5. In both male and female offspring (postnatal day 28-32), whole-cell patch clamp recording of layer V/VI somatosensory cortex pyramidal neurons revealed increases in the frequency of excitatory and inhibitory postsynaptic currents. Furthermore, expressing channelrhodopsin in either GABAergic interneurons (Nkx2.1Cre-Ai32) or glutamatergic pyramidal neurons (Emx1IRES Cre-Ai32) revealed a shift in optically evoked paired-pulse ratio. These findings are consistent with an excitatory-inhibitory imbalance with prenatal ethanol exposure due to diminished inhibitory but enhanced excitatory synaptic strength. Prenatal ethanol exposure also altered the density and morphology of spines along the apical dendrites of pyramidal neurons. Thus, while both presynaptic and postsynaptic mechanisms are affected following prenatal exposure to ethanol, there is a prominent presynaptic component that contributes to altered inhibitory and excitatory synaptic transmission in the somatosensory cortex.
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Affiliation(s)
- Laurie C Delatour
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Pamela W L Yeh
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Hermes H Yeh
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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10
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Delatour LC, Yeh PW, Yeh HH. Ethanol Exposure In Utero Disrupts Radial Migration and Pyramidal Cell Development in the Somatosensory Cortex. Cereb Cortex 2019; 29:2125-2139. [PMID: 29688328 PMCID: PMC6458911 DOI: 10.1093/cercor/bhy094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 04/05/2018] [Indexed: 11/13/2022] Open
Abstract
Deficits in sensory processing in Fetal Alcohol Spectrum Disorders (FASD) implicate dysfunction in the somatosensory cortex. However, the effects of prenatal ethanol exposure on the development of this region await elucidation. Here, we used an established mouse model of FASD with binge-type ethanol exposure from embryonic day 13.5-16.5 to investigate the effects of prenatal ethanol exposure on pyramidal neurons in the somatosensory cortex. Specifically, we focused on the radial migration of primordial pyramidal neurons during embryonic corticogenesis and their morphology and function during active synaptogenesis in early postnatal development. We found that prenatal ethanol exposure resulted in aberrant radial migration, particularly affecting the populations of postmitotic pyramidal neurons. In addition, there was an enduring effect of prenatal ethanol exposure on glutamate-mediated synaptic transmission in layer V/VI pyramidal neurons. This persisted beyond a transient decrease in pyramidal neuron dendritic complexity that was evident only during early postnatal development. Adolescent mice exposed prenatally to ethanol also displayed decreased tactile sensitivity, as revealed by a modified adhesive tape removal assay. Our findings demonstrate the persistent effects of binge-type in utero ethanol exposure on pyramidal neuron form and function and ultimately sensory processing, the latter being reminiscent of that seen in individuals with FASD.
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Affiliation(s)
- Laurie C Delatour
- Program in Experimental and Molecular Medicine, Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, 66 College Street, Hanover, NH, USA
| | - Pamela W Yeh
- Program in Experimental and Molecular Medicine, Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, 66 College Street, Hanover, NH, USA
| | - Hermes H Yeh
- Program in Experimental and Molecular Medicine, Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, 66 College Street, Hanover, NH, USA
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11
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Szabó Í, M. Tóth O, Török Z, Varga DP, Menyhárt Á, Frank R, Hantosi D, Hunya Á, Bari F, Horváth I, Vigh L, Farkas E. The impact of dihydropyridine derivatives on the cerebral blood flow response to somatosensory stimulation and spreading depolarization. Br J Pharmacol 2019; 176:1222-1234. [PMID: 30737967 PMCID: PMC6468258 DOI: 10.1111/bph.14611] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 01/07/2019] [Accepted: 01/11/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE A new class of dihydropyridine derivatives, which act as co-inducers of heat shock protein but are devoid of calcium channel antagonist and vasodilator effects, has recently been developed with the purpose of selectively targeting neurodegeneration. Here, we evaluated the action of one of these novel compounds LA1011 on neurovascular coupling in the ischaemic rat cerebral cortex. As a reference, we applied nimodipine, a vasodilator dihydropyridine and well-known calcium channel antagonist. EXPERIMENTAL APPROACH Rats were treated with LA1011 or nimodipine, either by chronic, systemic (LA1011), or acute, local administration (LA1011 and nimodipine). In the latter treatment group, global forebrain ischaemia was induced in half of the animals by bilateral common carotid artery occlusion under isoflurane anaesthesia. Functional hyperaemia in the somatosensory cortex was created by mechanical stimulation of the contralateral whisker pad under α-chloralose anaesthesia. Spreading depolarization (SD) events were elicited subsequently by 1 M KCl. Local field potential and cerebral blood flow (CBF) in the parietal somatosensory cortex were monitored by electrophysiology and laser Doppler flowmetry. KEY RESULTS LA1011 did not alter CBF, but intensified SD, presumably indicating the co-induction of heat shock proteins, and, perhaps an anti-inflammatory effect. Nimodipine attenuated evoked potentials and SD. In addition to the elevation of baseline CBF, nimodipine augmented hyperaemia in response to both somatosensory stimulation and SD, particularly under ischaemia. CONCLUSIONS AND IMPLICATIONS In contrast to the CBF improvement achieved with nimodipine, LA1011 seems not to have discernible cerebrovascular effects but may up-regulate the stress response.
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Affiliation(s)
- Írisz Szabó
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Orsolya M. Tóth
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Zsolt Török
- Institute of Biochemistry, Biological Research CentreHungarian Academy of SciencesSzegedHungary
- LipidArt Research and Development Ltd.SzegedHungary
| | - Dániel Péter Varga
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Rita Frank
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Dóra Hantosi
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Ákos Hunya
- LipidArt Research and Development Ltd.SzegedHungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
| | - Ibolya Horváth
- Institute of Biochemistry, Biological Research CentreHungarian Academy of SciencesSzegedHungary
| | - László Vigh
- Institute of Biochemistry, Biological Research CentreHungarian Academy of SciencesSzegedHungary
| | - Eszter Farkas
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
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12
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Chen W, Volkow ND, Li J, Pan Y, Du C. Cocaine Decreases Spontaneous Neuronal Activity and Increases Low-Frequency Neuronal and Hemodynamic Cortical Oscillations. Cereb Cortex 2019; 29:1594-1606. [PMID: 29912298 PMCID: PMC6418395 DOI: 10.1093/cercor/bhy057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 01/28/2018] [Accepted: 02/23/2018] [Indexed: 12/20/2022] Open
Abstract
Low-frequency oscillations (LFOs) in hemodynamics assessed by fMRI reflect synchronized neuronal activities and are the basis for mapping brain function and its disruption by drugs and disease. Here we assess if cocaine disrupts coupling between neuronal and vascular LFOs by simultaneously measuring cortical field potentials (FP) and cerebral blood flow (CBF) regarding their LFOs (0-1 Hz) spectral bandwidths in the somatosensory cortex of naïve and chronic cocaine-exposed rats at baseline and during cocaine intoxication. While across all conditions the dominant oscillation frequencies for FP and CBF LFOs were ~0.1 Hz, the bandwidth of FP LFOs was about 4.8 ± 0.67 times broader than that of CBF LFOs. Acute cocaine depressed high-frequency FP events but increased the relative intensity of neuronal and hemodynamic LFOs, an effect that was markedly accentuated in magnitude and duration in chronic cocaine-exposed animals. Neuronal LFOs were correlated with CBF LFOs in control animals but not in chronically cocaine-exposed animals, which suggests neurovascular uncoupling. The marked increases in neuronal LFOs with chronic cocaine, which we interpret to reflect increases in neuronal synchronization in the LFOs, and the uncoupling of hemodynamics with resting neuronal activities could contribute to brain dysfunction in cocaine abusers and confound the interpretation of fMRI studies.
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Affiliation(s)
- Wei Chen
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - James Li
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
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13
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Abstract
Motherhood in mammals involves tremendous changes throughout the body and central nervous system, which support attention and nurturing of infants. Maternal care consists of complex behaviors, such as nursing and protection of the offspring, requiring new mothers to become highly sensitive to infant needs. Long-lasting neural plasticity in various regions of the cerebral cortex may enable the perception and recognition of infant cues, important for appropriate caregiving responses. Recent findings have demonstrated that the neuropeptide oxytocin is involved in a number of physiological processes, including parturition and lactation and dynamically shaping neuronal responses to infant stimuli as well. Here, we review experience-dependent changes within the cortex occurring throughout motherhood, focusing on plasticity of the somatosensory and auditory cortex. We outline the role of oxytocin in gating cortical plasticity and discuss potential mechanisms regulating oxytocin release in response to different sensory stimuli.
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Affiliation(s)
- Silvana Valtcheva
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Neuroscience Institute, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Department of Otolaryngology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
- Department of Neuroscience and Physiology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Neuroscience Institute, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Department of Otolaryngology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Department of Neuroscience and Physiology, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
- Howard Hughes Medical Institute Faculty Scholar, New York University School of Medicine, 540 First Avenue, New York, NY, 10016, USA.
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14
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Stumpf A, Parthier D, Sammons RP, Stempel AV, Breustedt J, Rost BR, Schmitz D. Cannabinoid type 2 receptors mediate a cell type-specific self-inhibition in cortical neurons. Neuropharmacology 2018; 139:217-225. [PMID: 30025920 DOI: 10.1016/j.neuropharm.2018.07.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/25/2018] [Accepted: 07/13/2018] [Indexed: 01/06/2023]
Abstract
Endogenous cannabinoids are diffusible lipid ligands of the main cannabinoid receptors type 1 and 2 (CB1R and CB2R). In the central nervous system endocannabinoids are produced in an activity-dependent manner and have been identified as retrograde modulators of synaptic transmission. Additionally, some neurons display a cell-autonomous slow self-inhibition (SSI) mediated by endocannabinoids. In these neurons, repetitive action potential firing triggers the production of endocannabinoids, which induce a long-lasting hyperpolarization of the membrane potential, rendering the cells less excitable. Different endocannabinoid receptors and effector mechanisms have been described underlying SSI in different cell types and brain areas. Here, we investigate SSI in neurons of layer 2/3 in the somatosensory cortex. High-frequency bursts of action potentials induced SSI in pyramidal cells (PC) and regular spiking non-pyramidal cells (RSNPC), but not in fast-spiking interneurons (FS). In RSNPCs the hyperpolarization was accompanied by a change in input resistance due to the activation of G protein-coupled inward-rectifying K+ (GIRK) channels. A CB2R-specific agonist induced the long-lasting hyperpolarization, whereas preincubation with a CB2R-specific inverse agonist suppressed SSI. Additionally, using cannabinoid receptor knockout mice, we found that SSI was still intact in CB1R-deficient but abolished in CB2R-deficient mice. Taken together, we describe an additional SSI mechanism in which the activity-induced release of endocannabinoids activates GIRK channels via CB2Rs. These findings expand our knowledge about cell type-specific differential neuronal cannabinoid receptor signaling and suggest CB2R-selective compounds as potential therapeutic approaches.
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MESH Headings
- Animals
- Cannabinoid Receptor Modulators/pharmacology
- Endocannabinoids/metabolism
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Mice, Inbred C57BL
- Mice, Knockout
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Neurons/drug effects
- Neurons/metabolism
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/deficiency
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Somatosensory Cortex/drug effects
- Somatosensory Cortex/metabolism
- Tissue Culture Techniques
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Affiliation(s)
- Alexander Stumpf
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Daniel Parthier
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Rosanna P Sammons
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - A Vanessa Stempel
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, UK
| | - Jörg Breustedt
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany
| | - Benjamin R Rost
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Dietmar Schmitz
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany; Berlin Institute of Health, Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, Germany; Cluster of Excellence NeuroCure, Berlin, Germany; Einstein Center for Neurosciences, Berlin, Germany.
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15
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Fernandez FR, Rahsepar B, White JA. Differences in the Electrophysiological Properties of Mouse Somatosensory Layer 2/3 Neurons In Vivo and Slice Stem from Intrinsic Sources Rather than a Network-Generated High Conductance State. eNeuro 2018; 5:ENEURO.0447-17.2018. [PMID: 29662946 PMCID: PMC5898699 DOI: 10.1523/eneuro.0447-17.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/01/2018] [Accepted: 03/20/2018] [Indexed: 01/29/2023] Open
Abstract
Synaptic activity in vivo can potentially alter the integration properties of neurons. Using recordings in awake mice, we targeted somatosensory layer 2/3 pyramidal neurons and compared neuronal properties with those from slices. Pyramidal cells in vivo had lower resistance and gain values, as well as broader spikes and increased spike frequency adaptation compared to the same cells in slices. Increasing conductance in neurons using dynamic clamp to levels observed in vivo, however, did not lessen the differences between in vivo and slice conditions. Further, local application of tetrodotoxin (TTX) in vivo blocked synaptic-mediated membrane voltage fluctuations but had little impact on pyramidal cell membrane input resistance and time constant values. Differences in electrophysiological properties of layer 2/3 neurons in mouse somatosensory cortex, therefore, stem from intrinsic sources separate from synaptic-mediated membrane voltage fluctuations.
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Affiliation(s)
- Fernando R Fernandez
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215
| | - Bahar Rahsepar
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215
| | - John A White
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215
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16
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Lau LA, Noubary F, Wang D, Dulla CG. α2δ-1 Signaling Drives Cell Death, Synaptogenesis, Circuit Reorganization, and Gabapentin-Mediated Neuroprotection in a Model of Insult-Induced Cortical Malformation. eNeuro 2017; 4:ENEURO.0316-17.2017. [PMID: 29109971 PMCID: PMC5672548 DOI: 10.1523/eneuro.0316-17.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 01/08/2023] Open
Abstract
Developmental cortical malformations (DCMs) result from pre- and perinatal insults, as well as genetic mutations. Hypoxia, viral infection, and traumatic injury are the most common environmental causes of DCMs, and are associated with the subsyndromes focal polymicrogyria and focal cortical dysplasia (FCD) Type IIId, both of which have a high incidence of epilepsy. Understanding the molecular signals that lead to the formation of a hyperexcitable network in DCMs is critical to devising novel treatment strategies. In a previous study using the freeze-lesion (FL) murine model of DCM, we found that levels of thrombospondin (TSP) and the calcium channel auxiliary subunit α2δ-1 were elevated. TSP binds to α2δ-1 to drive the formation of excitatory synapses during development, suggesting that overactivation of this pathway may lead to exuberant excitatory synaptogenesis and network hyperexcitability seen in DCMs. In that study, antagonizing TSP/α2δ-1 signaling using the drug gabapentin (GBP) reduced many FL-induced pathologies. Here, we used mice with a genetic deletion of α2δ-1 to determine how α2δ-1 contributes to cell death, elevated excitatory synapse number, and in vitro network function after FL and to examine the molecular specificity of GBP's effects. We identified a critical role for α2δ-1 in FL-induced pathologies and in mediating the neuroprotective effects of GBP. Interestingly, genetic deletion of α2δ-1 did not eliminate GBP's effects on synaptogenesis, suggesting that GBP can have α2δ-1-independent effects. Taken together these studies suggests that inhibiting α2δ-1 signaling may have therapeutic promise to reduce cell death and network reorganization associated with insult-induced DCMs.
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Affiliation(s)
- Lauren A. Lau
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
- Neuroscience Program, Tufts Sackler School of Biomedical Sciences, Boston, MA 02111
| | - Farzad Noubary
- The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA 02111
- Tufts Clinical and Translational Science Institute, Tufts University, Boston, MA 02111
| | - Dongqing Wang
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Chris G. Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
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17
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Faria LC, Gu F, Parada I, Barres B, Luo ZD, Prince DA. Epileptiform activity and behavioral arrests in mice overexpressing the calcium channel subunit α2δ-1. Neurobiol Dis 2017; 102:70-80. [PMID: 28193459 DOI: 10.1016/j.nbd.2017.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/17/2017] [Accepted: 01/25/2017] [Indexed: 10/20/2022] Open
Abstract
The alpha2delta-1 subunit (α2δ-1) of voltage-gated calcium channels is a receptor for astrocyte-secreted thrombospondins that promote developmental synaptogenesis. Alpha2delta-1 receptors are upregulated in models of injury-induced peripheral pain and epileptogenic neocortical trauma associated with an enhancement of excitatory synaptic connectivity. These results lead to the hypothesis that overexpression of α2δ-1 alone in neocortex of uninjured transgenic (TG) mice might result in increased excitatory connectivity and consequent cortical hyperexcitability and epileptiform activity. Whole cell recordings from layer V pyramidal neurons in somatosensory cortical slices of TG mice showed increased frequency and amplitude of miniature and spontaneous EPSCs and prolonged bursts of polysynaptic EPSCs. Epileptiform field potentials were evoked in layers II/III and V of brain slices from TG mice, but not controls. Dual immunoreactivity for Vglut-2 and PSD95 showed increased density of close appositions in TG mice compared to controls, suggesting an increased number of excitatory synapses. Video-EEG monitoring showed that 13/13 implanted TG mice aged >P21, but not controls, had frequent abnormal spontaneous epileptiform events, consisting of variable duration, high amplitude bi-hemispheric irregular bursts of delta activity, spikes and sharp waves lasting many seconds, with a variable peak frequency of ~1-3Hz, associated with behavioral arrest. The epileptiform EEG abnormalities and behavioral arrests were reversibly eliminated by treatment with i.p. ethosuximide. Behavioral seizures, consisting of ~15-30s duration episodes of rigid arched tail and head and body extension, followed by loss of balance and falling, frequently occurred in adult TG mice during recovery from isoflurane-induced anesthesia, but were rare in WT mice. Results show that over-expression of α2δ-1 subunits increases cortical excitatory connectivity and leads to neocortical hyperexcitability and epileptiform activity associated with behavioral arrests in adult TG mice. Similar increases in expression of α2δ-1 in models of cortical injury may play an important role in epileptogenesis. SIGNIFICANCE Binding of astrocytic-secreted thrombospondins to their α2δ-1 receptor facilitates excitatory synapse formation and excitatory transmission during cortical development and after injury. Upregulation of α2δ-1 is present in models of injury-induced pain and epileptogenic cortical trauma, along with many other molecular alterations. Here we show that overexpression of α2δ-1 alone in TG mice can enhance excitatory connectivity in neocortex and lead to neural circuit hyperexcitability and episodes of electrographic epileptiform activity, associated with behavioral arrests in transgenic mice. α2δ-1 is the high-affinity receptor for gabapentinoids and a potential target for prophylactic treatment of posttraumatic epilepsy and other disorders in which excessive aberrant excitatory connectivity is a pathophysiological feature.
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Affiliation(s)
- Leonardo C Faria
- Department of Neurology and Neurological Sciences, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Feng Gu
- Department of Neurology and Neurological Sciences, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Isabel Parada
- Department of Neurology and Neurological Sciences, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Ben Barres
- Department of Neurobiology, Stanford University, Howard Hughes Medical Institute, Stanford School of Medicine, Stanford, CA 94305-5125, USA
| | - Z David Luo
- Department of Anesthesiology and Perioperative Care, Department of Pharmacology, University of California, Irvine Medical Center, Orange, CA 92868, USA
| | - David A Prince
- Department of Neurology and Neurological Sciences, Stanford University, School of Medicine, Stanford, CA 94305, USA.
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18
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Puskarjov M, Fiumelli H, Briner A, Bodogan T, Demeter K, Lacoh CM, Mavrovic M, Blaesse P, Kaila K, Vutskits L. K-Cl Cotransporter 2-mediated Cl- Extrusion Determines Developmental Stage-dependent Impact of Propofol Anesthesia on Dendritic Spines. Anesthesiology 2017; 126:855-867. [PMID: 28301408 DOI: 10.1097/aln.0000000000001587] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABAA)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). METHODS In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABAA)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. RESULTS The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. CONCLUSIONS The KCC2-dependent developmental increase in the efficacy of GABAA-mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.
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Affiliation(s)
- Martin Puskarjov
- From the Department of Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland (M.P., M.M., P.B., K.K.); Division of Biological and Environmental Sciences and Technology, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia (H.F.); Department of Anesthesiology, Pharmacology and Intensive Care, University Hospital of Geneva, Geneva, Switzerland (A.B., T.B., C.-M.L., L.V.); Department of Fundamental Neurosciences, University of Geneva Medical School, Geneva, Switzerland (A.B., T.B., K.D., L.V.); and Institute of Experimental Medicine of the Hungarian Academy of Sciences, Budapest, Hungary (K.D.). Current position: Institute of Physiology I, Westfälische Wilhelms-University Münster, Münster, Germany (P.B.)
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19
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Loh R, Chau L, Aijaz A, Wu K, Galvez R. Antagonizing the different stages of kappa opioid receptor activation selectively and independently attenuates acquisition and consolidation of associative memories. Behav Brain Res 2017; 323:1-10. [PMID: 28119127 DOI: 10.1016/j.bbr.2017.01.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 01/11/2017] [Accepted: 01/18/2017] [Indexed: 01/04/2023]
Abstract
Previous work from our laboratory has shown that nonspecific kappa opioid receptor (KOR) antagonism in primary somatosensory cortex (S1) can inhibit acquisition for the forebrain-dependent associative task, Whisker-Trace Eyeblink conditioning (WTEB). Although studies have demonstrated that KOR activation can alter stimuli salience, our studies controlled for these factors, demonstrating that KOR also plays a role in facilitating learning. KOR has two distinct phases of activation followed by internalization/downregulation, that each independently activate kinases and transcription factors known to mediate task acquisition and memory consolidation respectively. The current study demonstrated that antagonism of the initial phase of KOR activation in S1 via local injections of the g-protein inhibitor, pertussis toxin (PTX), blocked initial WTEB acquisition without affecting retention of the association. In contrast, KOR late phase antagonism in S1 via local injections of the GRK3-specific antagonist, guanidinonaltrindole (GNTI), blocked retention of the WTEB association without affecting task acquisition. Consistent with the known mechanism for KOR activation, KOR protein expression in S1 was found to be decreased following WTEB training, further supporting the involvement of neocortical KOR activation with learning. Prior studies have shown that task acquisition and memory consolidation are mediated by distinct molecular processes; however, little is known regarding a potential mechanism driving these processes. The current study suggests that neocortical KOR activation mediates activation of these processes with learning. This study provides the first evidence for a time- and learning-dependent property of neocortical KOR in facilitating acquisition and consolidation of associative memories, while elucidating an unexplored neocortical learning mechanism.
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Affiliation(s)
- Ryan Loh
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Lily Chau
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Ali Aijaz
- Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Kevin Wu
- Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Roberto Galvez
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
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20
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Rebuli ME, Gibson P, Rhodes CL, Cushing BS, Patisaul HB. Sex differences in microglial colonization and vulnerabilities to endocrine disruption in the social brain. Gen Comp Endocrinol 2016; 238:39-46. [PMID: 27102938 PMCID: PMC5067172 DOI: 10.1016/j.ygcen.2016.04.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 04/11/2016] [Accepted: 04/16/2016] [Indexed: 02/07/2023]
Abstract
During development, microglia, the resident immune cells of the brain, play an important role in synaptic organization. Microglial colonization of the developing brain is sexually dimorphic in some regions, including nuclei critical for the coordination of social behavior, suggesting steroid hormones have an influencing role, particularly estrogen. By extension, microglial colonization may be vulnerable to endocrine disruption. Concerns have been raised regarding the potential for endocrine disrupting compounds (EDCs) to alter brain development and behavior. Developmental exposure to Bisphenol A (BPA), a ubiquitous EDC, has been associated with altered sociosexual and mood-related behaviors in various animal models and children. Through a comparison of the promiscuous Wistar rat (Rattus norvegicus) and the socially monogamous prairie vole (Microtus ochrogaster), we are the first to observe that developmental exposure to the synthetic estrogen ethinyl estradiol (EE) or BPA alters the sex-specific colonization of the hippocampus and amygdala by microglia.
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Affiliation(s)
- Meghan E Rebuli
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA; W. M. Keck Center for Behavioral Biology, Raleigh, NC 27695, USA
| | - Paul Gibson
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Cassie L Rhodes
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Bruce S Cushing
- Department of Biological Sciences, University of Texas at El Paso, El Paso 79968, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA; W. M. Keck Center for Behavioral Biology, Raleigh, NC 27695, USA; NCSU Center for Human Health and the Environment, Raleigh, NC 27695, USA.
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21
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Levitan D, Fortis-Santiago Y, Figueroa JA, Reid EE, Yoshida T, Barry NC, Russo A, Katz DB. Memory Retrieval Has a Dynamic Influence on the Maintenance Mechanisms That Are Sensitive to ζ-Inhibitory Peptide (ZIP). J Neurosci 2016; 36:10654-10662. [PMID: 27733615 PMCID: PMC5059432 DOI: 10.1523/jneurosci.1568-16.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/25/2016] [Accepted: 08/28/2016] [Indexed: 12/22/2022] Open
Abstract
In neuroscientists' attempts to understand the long-term storage of memory, topics of particular importance and interest are the cellular and system mechanisms of maintenance (e.g., those sensitive to ζ-inhibitory peptide, ZIP) and those induced by memory retrieval (i.e., reconsolidation). Much is known about each of these processes in isolation, but less is known concerning how they interact. It is known that ZIP sensitivity and memory retrieval share at least some molecular targets (e.g., recycling α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, AMPA, receptors to the plasma membrane); conversely, the fact that sensitivity to ZIP emerges only after consolidation ends suggests that consolidation (and by extension reconsolidation) and maintenance might be mutually exclusive processes, the onset of one canceling the other. Here, we use conditioned taste aversion (CTA) in rats, a cortically dependent learning paradigm, to test this hypothesis. First, we demonstrate that ZIP infusions into gustatory cortex begin interfering with CTA memory 43-45 h after memory acquisition-after consolidation ends. Next, we show that a retrieval trial administered after this time point interrupts the ability of ZIP to induce amnesia and that ZIP's ability to induce amnesia is reengaged only 45 h after retrieval. This pattern of results suggests that memory retrieval and ZIP-sensitive maintenance mechanisms are mutually exclusive and that the progression from one to the other are similar after acquisition and retrieval. They also reveal concrete differences between ZIP-sensitive mechanisms induced by acquisition and retrieval: the latency with which ZIP-sensitive mechanisms are expressed differ for the two processes. SIGNIFICANCE STATEMENT Memory retrieval and the molecular mechanisms that are sensitive to ζ-inhibitory peptide (ZIP) are the few manipulations that have been shown to effect memory maintenance. Although much is known about their effect on maintenance separately, it is unknown how they interact. Here, we describe a model for the interaction between memory retrieval and ZIP-sensitive mechanisms, showing that retrieval trials briefly (i.e., for 45 h) interrupt these mechanisms. ZIP sensitivity emerges across a similar time window after memory acquisition and retrieval; the maintenance mechanisms that follow acquisition and retrieval differ, however, in the latency with which the impact of ZIP is expressed.
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Affiliation(s)
| | | | | | | | - Takashi Yoshida
- Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454
| | | | | | - Donald B Katz
- Program of Neuroscience, Department of Psychology, and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454
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Cecchetto C, Mahmud M, Vassanelli S. Anesthesia effect on single local field potentials variability in rat barrel cortex: Preliminary results. Annu Int Conf IEEE Eng Med Biol Soc 2016; 2015:4721-4. [PMID: 26737348 DOI: 10.1109/embc.2015.7319448] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The rat barrel cortex is a widely used model of information processing in the somatosensory area, thanks to its precise and easily recognizable organization. However, evoked Local Field Potentials (LFPs) generated in the barrel cortex by repetitive deflections of rat whiskers show large variability in shapes and timings. Moreover, anesthetics can deeply affect the profile of evoked responses. This paper presents preliminary report on the variability and the effect of commonly used anesthetics on these signals. We studied representative signal shape characteristics (e.g., latency and amplitude of events) extracted from evoked responses acquired by means of standard Ag/AgCl electrodes from different cortical layers. As an early result, we found significant difference in the latency of the first principal peak of the responses. Under Tiletamine-Xylazine anesthetic, the responses or events of the evoked LFPs occurred later than the ones recorded while urethane was administered. Furthermore, the distributions of the peak latencies in all cortical layers were narrower in case of Urethane. This behavior should be attributed to the different effects of these two anesthetics on specific synaptic receptors and thus on the processing of neural information and the encoding of sensory input along the cortical pathway.
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Bray N, Burrows FE, Jones M, Berwick J, Allan SM, Schiessl I. Decreased haemodynamic response and decoupling of cortical gamma-band activity and tissue oxygen perfusion after striatal interleukin-1 injection. J Neuroinflammation 2016; 13:195. [PMID: 27557843 PMCID: PMC4997780 DOI: 10.1186/s12974-016-0664-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/18/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Neurovascular coupling describes the mechanism by which the energy and oxygen demand arising from neuronal activity is met by an increase in regional blood flow, known as the haemodynamic response. Interleukin 1 (IL-1) is a pro-inflammatory cytokine and an important mediator of neuronal injury, though mechanisms through which IL-1 exerts its effects in the brain are not fully understood. In this study, we set out to investigate if increased cerebral levels of IL-1 have a negative effect on the neurovascular coupling in the cortex in response to sensory stimulation. METHODS We used two approaches to measure the neuronal activity and haemodynamic changes in the anaesthetised rat barrel somatosensory cortex in response to mechanical whisker stimulation, before and for 6 h after intra-striatal injection of interleukin-1β or vehicle. First, we used two-dimensional optical imaging spectroscopy (2D-OIS) to measure the size of the functional haemodynamic response, indicated by changes of oxyhaemoglobin (HbO2) and total haemoglobin (HbT) concentration. In the same animals, immunostaining of immunoglobulin G and SJC-positive extravasated neutrophils was used to confirm the pro-inflammatory effects of interleukin-1β (IL-1β). Second, to examine the functional coupling between neuronal activity and the haemodynamic response, we used a 'Clark-style' electrode combined with a single sharp electrode to simultaneously record local tissue oxygenation (partial pressure oxygen, pO2) in layer IV/V of the stimulated barrel cortex and multi-unit activity (MUA) together with local field potentials (LFPs), respectively. RESULTS 2D-OIS data revealed that the size of the haemodynamic response to mechanical whisker stimulation declined over the 6 h following IL-1β injection whereas the vehicle group remained stable, significant differences being seen after 5 h. Moreover, the size of the transient increases of neuronal LFP activity in response to whisker stimulation decreased after IL-1β injection, significant changes compared to vehicle being seen for gamma-band activity after 1 h and beta-band activity after 3 h. The amplitude of the functional pO2 response similarly decreased after 3 h post-IL-1β injection, whereas IL-1β had no significant effect on the peak of whisker-stimulation-induced MUA. The stimulation-evoked increases in gamma power and pO2 correlated significantly throughout the 6 h in the vehicle group, but such a correlation was not observed in the IL-1β-injected group. CONCLUSIONS We conclude that intra-striatal IL-1β decouples cortical neuronal activity from its haemodynamic response. This finding may have implications for neurological conditions where IL-1β plays a part, especially those involving reductions in cerebral blood flow (such as stroke).
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Affiliation(s)
- Natasha Bray
- Faculty of Life Sciences, The University of Manchester, Oxford Rd, Manchester, M13 9PT UK
| | - Fiona E. Burrows
- Faculty of Life Sciences, The University of Manchester, Oxford Rd, Manchester, M13 9PT UK
| | - Myles Jones
- Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP UK
| | - Jason Berwick
- Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP UK
| | - Stuart M. Allan
- Faculty of Life Sciences, The University of Manchester, Oxford Rd, Manchester, M13 9PT UK
| | - Ingo Schiessl
- Faculty of Life Sciences, The University of Manchester, Oxford Rd, Manchester, M13 9PT UK
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Abstract
The cortex connects to the thalamus via extensive corticothalamic (CT) pathways, but their function in vivo is not well understood. We investigated "top-down" signaling from cortex to thalamus via the cortical layer 5B (L5B) to posterior medial nucleus (POm) pathway in the whisker system of the anesthetized mouse. While L5B CT inputs to POm are extremely strong in vitro, ongoing activity of L5 neurons in vivo might tonically depress these inputs and thereby block CT spike transfer. We find robust transfer of spikes from the cortex to the thalamus, mediated by few L5B-POm synapses. However, the gain of this pathway is not constant but instead is controlled by global cortical Up and Down states. We characterized in vivo CT spike transfer by analyzing unitary PSPs and found that a minority of PSPs drove POm spikes when CT gain peaked at the beginning of Up states. CT gain declined sharply during Up states due to frequency-dependent adaptation, resulting in periodic high gain-low gain oscillations. We estimate that POm neurons receive few (2-3) active L5B inputs. Thus, the L5B-POm pathway strongly amplifies the output of a few L5B neurons and locks thalamic POm sub-and suprathreshold activity to cortical L5B spiking.
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Affiliation(s)
- Rebecca A. Mease
- Institute for Neuroscience of the Technische Universität München, 80802 Munich, Germany
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Anton Sumser
- Institute for Neuroscience of the Technische Universität München, 80802 Munich, Germany
| | - Bert Sakmann
- Institute for Neuroscience of the Technische Universität München, 80802 Munich, Germany
- Max Planck Institute for Neurobiology, 82152 Martinsried, Germany
| | - Alexander Groh
- Institute for Neuroscience of the Technische Universität München, 80802 Munich, Germany
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany
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Asad ABA, Seah S, Baumgartner R, Feng D, Jensen A, Manigbas E, Henry B, Houghton A, Evelhoch JL, Derbyshire SWG, Chin CL. Distinct BOLD fMRI Responses of Capsaicin-Induced Thermal Sensation Reveal Pain-Related Brain Activation in Nonhuman Primates. PLoS One 2016; 11:e0156805. [PMID: 27309348 PMCID: PMC4911046 DOI: 10.1371/journal.pone.0156805] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 05/18/2016] [Indexed: 01/05/2023] Open
Abstract
Background Approximately 20% of the adult population suffer from chronic pain that is not adequately treated by current therapies, highlighting a great need for improved treatment options. To develop effective analgesics, experimental human and animal models of pain are critical. Topically/intra-dermally applied capsaicin induces hyperalgesia and allodynia to thermal and tactile stimuli that mimics chronic pain and is a useful translation from preclinical research to clinical investigation. Many behavioral and self-report studies of pain have exploited the use of the capsaicin pain model, but objective biomarker correlates of the capsaicin augmented nociceptive response in nonhuman primates remains to be explored. Methodology Here we establish an aversive capsaicin-induced fMRI model using non-noxious heat stimuli in Cynomolgus monkeys (n = 8). BOLD fMRI data were collected during thermal challenge (ON:20 s/42°C; OFF:40 s/35°C, 4-cycle) at baseline and 30 min post-capsaicin (0.1 mg, topical, forearm) application. Tail withdrawal behavioral studies were also conducted in the same animals using 42°C or 48°C water bath pre- and post- capsaicin application (0.1 mg, subcutaneous, tail). Principal Findings Group comparisons between pre- and post-capsaicin application revealed significant BOLD signal increases in brain regions associated with the ‘pain matrix’, including somatosensory, frontal, and cingulate cortices, as well as the cerebellum (paired t-test, p<0.02, n = 8), while no significant change was found after the vehicle application. The tail withdrawal behavioral study demonstrated a significant main effect of temperature and a trend towards capsaicin induced reduction of latency at both temperatures. Conclusions These findings provide insights into the specific brain regions involved with aversive, ‘pain-like’, responses in a nonhuman primate model. Future studies may employ both behavioral and fMRI measures as translational biomarkers to gain deeper understanding of pain processing and evaluate the preclinical efficacy of novel analgesics.
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Affiliation(s)
- Abu Bakar Ali Asad
- Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore
- * E-mail:
| | - Stephanie Seah
- Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore
| | - Richard Baumgartner
- Biometrics Research, Biostatistics & Research Decision Sciences, Merck Research Laboratories, Merck & Co., Rahway, NJ, United States of America
| | - Dai Feng
- Biometrics Research, Biostatistics & Research Decision Sciences, Merck Research Laboratories, Merck & Co., Rahway, NJ, United States of America
| | - Andres Jensen
- Early Discovery Pharmacology, Merck Research Laboratories, MSD, Singapore, Singapore
| | | | - Brian Henry
- Early Discovery Pharmacology, Merck Research Laboratories, MSD, Singapore, Singapore
| | - Andrea Houghton
- Early Discovery Pharmacology, Merck Research Laboratories, Merck & Co., West Point, PA, United States of America
| | - Jeffrey L. Evelhoch
- Translational Biomarkers, Merck Research Laboratories, Merck & Co., West Point, PA, United States of America
| | - Stuart W. G. Derbyshire
- Dept of Psychology, National University of Singapore, Singapore, Singapore
- A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore
| | - Chih-Liang Chin
- Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore
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Bogdanov VB, Middleton NA, Theriot JJ, Parker PD, Abdullah OM, Ju YS, Hartings JA, Brennan KC. Susceptibility of Primary Sensory Cortex to Spreading Depolarizations. J Neurosci 2016; 36:4733-43. [PMID: 27122032 PMCID: PMC4846671 DOI: 10.1523/jneurosci.3694-15.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED Spreading depolarizations (SDs) are recognized as actors in neurological disorders as diverse as migraine and traumatic brain injury (TBI). Migraine aura involves sensory percepts, suggesting that sensory cortices might be intrinsically susceptible to SDs. We used optical imaging, MRI, and field potential and potassium electrode recordings in mice and electrocorticographic recordings in humans to determine the susceptibility of different brain regions to SDs. Optical imaging experiments in mice under isoflurane anesthesia showed that both cortical spreading depression and terminal anoxic depolarization arose preferentially in the whisker barrel region of parietal sensory cortex. MRI recordings under isoflurane, ketamine/xylazine, ketamine/isoflurane, and urethane anesthesia demonstrated that the depolarizations did not propagate from a subcortical source. Potassium concentrations showed larger increases in sensory cortex, suggesting a mechanism of susceptibility. Sensory stimulation biased the timing but not the location of depolarization onset. In humans with TBI, there was a trend toward increased incidence of SDs in parietal/temporal sensory cortex compared with other regions. In conclusion, SDs are inducible preferentially in primary sensory cortex in mice and most likely in humans. This tropism can explain the predominant sensory phenomenology of migraine aura. It also demonstrates that sensory cortices are vulnerable in brain injury. SIGNIFICANCE STATEMENT Spreading depolarizations (SDs) are involved in neurologic disorders as diverse as migraine and traumatic brain injury. In migraine, the nature of aura symptoms suggests that sensory cortex may be preferentially susceptible. In brain injury, SDs occur at a vulnerable time, during which the issue of sensory stimulation is much debated. We show, in mouse and human, that sensory cortex is more susceptible to SDs. We find that sensory stimulation biases the timing but not the location of the depolarizations. Finally, we show a relative impairment of potassium clearance in sensory cortex, providing a potential mechanism for the susceptibility. Our data help to explain the sensory nature of the migraine aura and reveal that sensory cortices are vulnerable in brain injury.
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Affiliation(s)
| | | | | | - Patrick D Parker
- Department of Neurology, Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah 84108
| | | | - Y Sungtaek Ju
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, and
| | - Jed A Hartings
- Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio 45220
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27
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Kwakowsky A, Potapov K, Kim S, Peppercorn K, Tate WP, Ábrahám IM. Treatment of beta amyloid 1-42 (Aβ(1-42))-induced basal forebrain cholinergic damage by a non-classical estrogen signaling activator in vivo. Sci Rep 2016; 6:21101. [PMID: 26879842 PMCID: PMC4754683 DOI: 10.1038/srep21101] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/18/2016] [Indexed: 11/09/2022] Open
Abstract
In Alzheimer's disease (AD), there is a loss in cholinergic innervation targets of basal forebrain which has been implicated in substantial cognitive decline. Amyloid beta peptide (Aβ(1-42)) accumulates in AD that is highly toxic for basal forebrain cholinergic (BFC) neurons. Although the gonadal steroid estradiol is neuroprotective, the administration is associated with risk of off-target effects. Previous findings suggested that non-classical estradiol action on intracellular signaling pathways has ameliorative potential without estrogenic side effects. After Aβ(1-42) injection into mouse basal forebrain, a single dose of 4-estren-3α, 17β-diol (estren), the non-classical estradiol pathway activator, restored loss of cholinergic cortical projections and also attenuated the Aβ(1-42)-induced learning deficits. Estren rapidly and directly phosphorylates c-AMP-response-element-binding-protein and extracellular-signal-regulated-kinase-1/2 in BFC neurons and restores the cholinergic fibers via estrogen receptor-α. These findings indicated that selective activation of non-classical intracellular estrogen signaling has a potential to treat the damage of cholinergic neurons in AD.
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Affiliation(s)
- Andrea Kwakowsky
- Centre for Neuroendocrinology and Department of Physiology, Otago Medical School, University of Otago, Dunedin, New Zealand
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Kyoko Potapov
- Centre for Neuroendocrinology and Department of Physiology, Otago Medical School, University of Otago, Dunedin, New Zealand
| | - SooHyun Kim
- Centre for Neuroendocrinology and Department of Physiology, Otago Medical School, University of Otago, Dunedin, New Zealand
| | - Katie Peppercorn
- Department of Biochemistry, Otago Medical School, University of Otago, Dunedin, New Zealand
| | - Warren P. Tate
- Department of Biochemistry, Otago Medical School, University of Otago, Dunedin, New Zealand
| | - István M. Ábrahám
- Centre for Neuroendocrinology and Department of Physiology, Otago Medical School, University of Otago, Dunedin, New Zealand
- MTA-NAP-B-Molecular Neuroendocrinology Research Group, Centre for Neuroscience, Szentágothai Research Centre, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary
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28
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Rosenberg T, Elkobi A, Dieterich DC, Rosenblum K. NMDAR-dependent proteasome activity in the gustatory cortex is necessary for conditioned taste aversion. Neurobiol Learn Mem 2016; 130:7-16. [PMID: 26785229 DOI: 10.1016/j.nlm.2016.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/06/2016] [Accepted: 01/09/2016] [Indexed: 11/15/2022]
Abstract
Taste information is processed in different brain structures in the mammalian brain, including the gustatory cortex (GC), which resides within the insular cortex. N-methyl-d-aspartate receptor (NMDAR) activity in the GC is necessary for the acquisition of conditioned taste aversion (CTA) but not positive novel taste learning. Previous studies have shown that taste memory consolidation requires intact protein synthesis in the GC. In addition, the direct involvement of translation initiation and elongation factors was documented in the GC during taste learning. However, protein expression is defined by protein synthesis, degradation, and localization. Protein degradation is critical for the consolidation and reconsolidation of other forms of learning, such as fear learning and addiction behavior, but its role in cortical-dependent learning is not clear. Here, we show for the first time that proteasome activity is specifically increased in the GC 4h following experiencing of a novel taste. This increase in proteasome activity was abolished by local administration to the GC of the NMDA antagonist, APV, as well as a CaMKII inhibitor, at the time of acquisition. In addition, local application of lactacystin, a proteasome inhibitor, resulted in impaired CTA, but not novel taste learning. These results suggest that NMDAR-dependent proteasome activity in the GC participates in the association process between novel taste experience and negative visceral sensation.
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Affiliation(s)
- Tali Rosenberg
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel
| | - Alina Elkobi
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel
| | - Daniela C Dieterich
- Institute for Pharmacology and Toxicology, Medical Faculty, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, Magdeburg 39120, Germany
| | - Kobi Rosenblum
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel; Center for Gene Manipulation in the Brain, University of Haifa, Haifa 3498838, Israel.
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29
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Reyes-Puerta V, Yang JW, Siwek ME, Kilb W, Sun JJ, Luhmann HJ. Propagation of spontaneous slow-wave activity across columns and layers of the adult rat barrel cortex in vivo. Brain Struct Funct 2016; 221:4429-4449. [PMID: 26754838 DOI: 10.1007/s00429-015-1173-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/16/2015] [Indexed: 12/19/2022]
Abstract
During slow-wave sleep, neocortical networks exhibit self-organized activity switching between periods of concurrent spiking (up-states) and periods of network silence (down-states), a phenomenon also occurring under the effects of different anesthetics and in in vitro brain slice preparations. Although this type of ongoing activity has been implicated into important functions such as memory consolidation and learning, the manner in which it propagates across different cortical modules (i.e., columns and layers) has not been fully characterized. In the present study, we investigated this issue by measuring spontaneous activity at large scale in the adult rat barrel cortex under urethane anesthesia by means of voltage-sensitive dye imaging and 128-channel probe recordings. Up to 74 neurons located in all layers of up to four functionally identified barrel-related columns were recorded simultaneously. The spontaneous activity propagated isotropically across the cortical surface with a median speed of ~35 µm/ms. A concomitant radial spread of activation was present from deep to superficial cortical layers. Thus, spontaneous activity occurred rather globally in the barrel cortex, with ≥50 % of the up-states presenting spikes in ≥3 columns and layers. Temporally precise spike sequences, which occurred repeatedly (although sporadically) within the up-states, were typically led by putative excitatory neurons in the infragranular cortical layers. In summary, our data provide for the first time an overall view of the spontaneous slow-wave activity within the barrel cortex circuit, characterizing its propagation across columns and layers at high spatio-temporal resolution.
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Affiliation(s)
- Vicente Reyes-Puerta
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Magdalena E Siwek
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Jyh-Jang Sun
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
- Neuro-Electronics Research Flanders, Kapeldreef 75, 3001, Louvain, Belgium.
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
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30
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Posluszny A, Liguz-Lecznar M, Turzynska D, Zakrzewska R, Bielecki M, Kossut M. Learning-Dependent Plasticity of the Barrel Cortex Is Impaired by Restricting GABA-Ergic Transmission. PLoS One 2015; 10:e0144415. [PMID: 26641862 PMCID: PMC4671550 DOI: 10.1371/journal.pone.0144415] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 11/18/2015] [Indexed: 11/22/2022] Open
Abstract
Experience-induced plastic changes in the cerebral cortex are accompanied by alterations in excitatory and inhibitory transmission. Increased excitatory drive, necessary for plasticity, precedes the occurrence of plastic change, while decreased inhibitory signaling often facilitates plasticity. However, an increase of inhibitory interactions was noted in some instances of experience-dependent changes. We previously reported an increase in the number of inhibitory markers in the barrel cortex of mice after fear conditioning engaging vibrissae, observed concurrently with enlargement of the cortical representational area of the row of vibrissae receiving conditioned stimulus (CS). We also observed that an increase of GABA level accompanied the conditioning. Here, to find whether unaltered GABAergic signaling is necessary for learning-dependent rewiring in the murine barrel cortex, we locally decreased GABA production in the barrel cortex or reduced transmission through GABAA receptors (GABAARs) at the time of the conditioning. Injections of 3-mercaptopropionic acid (3-MPA), an inhibitor of glutamic acid decarboxylase (GAD), into the barrel cortex prevented learning-induced enlargement of the conditioned vibrissae representation. A similar effect was observed after injection of gabazine, an antagonist of GABAARs. At the behavioral level, consistent conditioned response (cessation of head movements in response to CS) was impaired. These results show that appropriate functioning of the GABAergic system is required for both manifestation of functional cortical representation plasticity and for the development of a conditioned response.
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Affiliation(s)
- Anna Posluszny
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Monika Liguz-Lecznar
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Danuta Turzynska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Renata Zakrzewska
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Maksymilian Bielecki
- Department of Psychology, SWPS University of Social Sciences and Humanities, Warsaw, Poland
| | - Malgorzata Kossut
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland
- Department of Psychology, SWPS University of Social Sciences and Humanities, Warsaw, Poland
- * E-mail:
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31
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Matukhno AE, Lysenko LV, Andreeva YV, Sukhov AG. [Influence of GABA(C)-Receptor Antagonist on Formation of Evoked Potentials in Columns of the Rat Somatosensory Cortex]. Zh Vyssh Nerv Deiat Im I P Pavlova 2015; 65:735-746. [PMID: 26841661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microelectrode studies of evoked potentials (EP) in neuronal column of rats barrel cortex show activating action of selective GABA(C)-receptor antagonist 1,2,5,6-tetrahydropyridin-4-yl-methylphosphinic acid (TPMPA) mainly on secondary components of EP of supragranular afferent layers of column compared to the efferent infragranular layers. These data suggest localization of GABA(C)-receptors on pre- synaptic terminals of thalamo-cortical glutamatergic afferents and ascending apical dendrites of pyramidal cells. A blockade of GABA(C)-receptors with the selective antagonist TPM PA leads to dose-dependent afferent depolarization with development of presynaptic inhibition and suppression of primary components of EP GABA(C)-receptors blocker produces different effects on secondary components of EP in supragranular layers of the cortex caused by the development of neuronal after hyperpolarization followed by high-amplitude primary response and afterdepolarization followed by low-amplitude primary responses with subsequent activation of different voltage-gated channels and formation of different level of cortical direct current potential gradients.
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32
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Baek K, Shim WH, Jeong J, Radhakrishnan H, Rosen BR, Boas D, Franceschini M, Biswal BB, Kim YR. Layer-specific interhemispheric functional connectivity in the somatosensory cortex of rats: resting state electrophysiology and fMRI studies. Brain Struct Funct 2015; 221:2801-15. [PMID: 26077581 DOI: 10.1007/s00429-015-1073-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 06/01/2015] [Indexed: 11/26/2022]
Abstract
The spontaneous cerebral hemodynamic fluctuations observed during the resting state have been frequently visualized using functional magnetic resonance imaging (rsfMRI). However, the neuronal populations and neuroelectric characteristics underlying the functional connectivity of cerebrohemodynamic activities are poorly understood. We investigated the characteristics of bi-hemispheric functional connectivity via electrophysiology and rsfMRI in the primary sensory cortex of rats anesthetized by α-chloralose. Unlike the evoked responses, the spontaneous electrophysiological activity was concentrated in the infragranular layers and could be classified into subtypes with distinctive current sources and sinks. Both neuroelectric and rsfMRI signals were interhemispherically correlated in a layer-specific manner, suggesting that there are independent neural inputs to infragranular and granular/supragranular layers. The majority of spontaneous electrophysiological activities were bilaterally paired with delays of up to ~50 ms between each pair. The variable interhemispheric delay implies the involvement of indirect, multi-neural pathways. Our findings demonstrated the diverse activity patterns of layer-specific electrophysiological substrates and suggest the recruitment of multiple, non-specific brain regions in construction of interhemispheric functional connectivity.
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Affiliation(s)
- Kwangyeol Baek
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, South Korea
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA
| | - Woo Hyun Shim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, South Korea
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA
| | - Jaeseung Jeong
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, South Korea.
| | - Harsha Radhakrishnan
- Center for Neural Engineering, Pennsylvania State University, University Park, PA, USA
| | - Bruce R Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA
- Harvard Medical School, Boston, MA, USA
| | - David Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA
- Harvard Medical School, Boston, MA, USA
| | - Maria Franceschini
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA
- Harvard Medical School, Boston, MA, USA
| | - Bharat B Biswal
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Young R Kim
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA, 02129, USA.
- Harvard Medical School, Boston, MA, USA.
- Ulsan National Institute of Science and Technology, Ulsan, South Korea.
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Höflich A, Hahn A, Küblböck M, Kranz GS, Vanicek T, Windischberger C, Saria A, Kasper S, Winkler D, Lanzenberger R. Ketamine-Induced Modulation of the Thalamo-Cortical Network in Healthy Volunteers As a Model for Schizophrenia. Int J Neuropsychopharmacol 2015; 18:pyv040. [PMID: 25896256 PMCID: PMC4576520 DOI: 10.1093/ijnp/pyv040] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 04/03/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Schizophrenia has been associated with disturbances of thalamic functioning. In light of recent evidence suggesting a significant impact of the glutamatergic system on key symptoms of schizophrenia, we assessed whether modulation of the glutamatergic system via blockage of the N-methyl-D-aspartate (NMDA)-receptor might lead to changes of thalamic functional connectivity. METHODS Based on the ketamine model of psychosis, we investigated changes in cortico-thalamic functional connectivity by intravenous ketamine challenge during a 55-minute resting-state scan. Thirty healthy volunteers were measured with pharmacological functional magnetic resonance imaging using a double-blind, randomized, placebo-controlled, crossover design. RESULTS Functional connectivity analysis revealed significant ketamine-specific changes within the thalamus hub network, more precisely, an increase of cortico-thalamic connectivity of the somatosensory and temporal cortex. CONCLUSIONS Our results indicate that changes of thalamic functioning as described for schizophrenia can be partly mimicked by NMDA-receptor blockage. This adds substantial knowledge about the neurobiological mechanisms underlying the profound changes of perception and behavior during the application of NMDA-receptor antagonists.
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Affiliation(s)
- Anna Höflich
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Andreas Hahn
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Martin Küblböck
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Georg S Kranz
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Thomas Vanicek
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Christian Windischberger
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Alois Saria
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Dietmar Winkler
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria)
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy (Drs Höflich, Hahn, Kranz, Vanicek, Kasper, Winkler, and Lanzenberger), and MR Center of Excellence and Center for Biomedical Engineering and Physics (Mr Küblböck and Dr Windischberger), Medical University of Vienna, Vienna, Austria; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria (Dr Saria).
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Isaeva EV, Lunko OO, Romano AK, Isaev DS. [EFFECT OF NEONATAL SEIZURES ON THE SYNAPTIC PLASTICITY OF RAT SOMATOSENSORY CORTEX]. ACTA ACUST UNITED AC 2015; 61:11-6. [PMID: 27025040 DOI: 10.15407/fz61.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Using an experimental model of neonatal recurrent seizures we investigated the influence of epileptic seizures in the various forms of synaptic plasticity in neurons of the somatosensory cortex. We found that early seizures do not affect the post-tetanic potentiation of the amplitude of the postsynaptic potentials and the depression of postsynaptic potentials during high-frequency stimulation. However they result in the chronic increase of the long-term potentiation of synaptic transmission. These changes of synaptic plasticity may affect the processing of the sensory information in patients with a history of recurrent seizures during early development.
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Tian MK, Bailey CDC, Lambe EK. Cholinergic excitation in mouse primary vs. associative cortex: region-specific magnitude and receptor balance. Eur J Neurosci 2014; 40:2608-18. [PMID: 24827827 PMCID: PMC4640901 DOI: 10.1111/ejn.12622] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/18/2014] [Accepted: 04/14/2014] [Indexed: 01/19/2023]
Abstract
Cholinergic stimulation of the cerebral cortex is essential for tasks requiring attention; however, there is still some debate over which cortical regions are required for such tasks. There is extensive cholinergic innervation of both primary and associative cortices, and transient release of acetylcholine (ACh) is detected in deep layers of the relevant primary and/or associative cortex, depending on the nature of the attention task. Here, we investigated the electrophysiological effects of ACh in layer VI, the deepest layer, of the primary somatosensory cortex, the primary motor cortex, and the associative medial prefrontal cortex. Layer VI pyramidal neurons are a major source of top-down modulation of attention, and we found that the strength and homogeneity of their direct cholinergic excitation was region-specific. On average, neurons in the primary cortical regions showed weaker responses to ACh, mediated by a balance of contributions from both nicotinic and muscarinic ACh receptors. Conversely, neurons in the associative medial prefrontal cortex showed significantly stronger excitation by ACh, mediated predominantly by nicotinic receptors. The greatest diversity of responses to ACh was found in the primary somatosensory cortex, with only a subset of neurons showing nicotinic excitation. In a mouse model with attention deficits only under demanding conditions, cholinergic excitation was preserved in primary cortical regions but not in the associative medial prefrontal cortex. These findings demonstrate that the effect of ACh is not uniform throughout the cortex, and suggest that its ability to enhance attention performance may involve different cellular mechanisms across cortical regions.
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Affiliation(s)
- Michael K. Tian
- Department of Physiology, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada, M5S 1A8
| | - Craig D. C. Bailey
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Evelyn K. Lambe
- Department of Physiology, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada, M5S 1A8
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, ON, Canada
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Chen JR, Tseng GF, Wang YJ, Wang TJ. Exogenous dehydroisoandrosterone sulfate reverses the dendritic changes of the central neurons in aging male rats. Exp Gerontol 2014; 57:191-202. [PMID: 24929010 DOI: 10.1016/j.exger.2014.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 06/06/2014] [Accepted: 06/11/2014] [Indexed: 12/13/2022]
Abstract
Sex hormones are known to help maintaining the cognitive ability in male and female rats. Hypogonadism results in the reduction of the dendritic spines of central neurons which is believed to undermine memory and cognition and cause fatigue and poor concentration. In our previous studies, we have reported age-related regression in dendrite arbors along with loss of dendritic spines in the primary somatosensory cortical neurons in female rats. Furthermore, castration caused a reduction of dendritic spines in adult male rats. In light of this, it was surmised that dendritic structures might change in normal aging male rats with advancing age. Recently, dehydroepiandrosterone sulfate (DHEAS) has been reported to have memory-enhancing properties in aged rodents. In this study, normal aging male rats, with a reduced plasma testosterone level of 75-80%, were used to explore the changes in behavioral performance of neuronal dendritic arbor and spine density. Aging rats performed poorer in spatial learning memory (Morris water maze). Concomitantly, these rats showed regressed dendritic arbors and spine loss on the primary somatosensory cortical and hippocampal CA1 pyramidal neurons. Exogenous DHEAS and testosterone treatment reversed the behavioral deficits and partially restored the spine loss of cortical neurons in aging male rats but had no effects on the dendritic arbor shrinkage of the affected neurons. It is concluded therefore that DHEAS, has the efficacy as testosterone, and that it can exert its effects on the central neuron level to effectively ameliorate aging symptoms.
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Affiliation(s)
- Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan.
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Tsyr-Jiuan Wang
- Department of Nursing, National Taichung University of Science and Technology, Taichung, Taiwan.
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Xerri C, Zennou-Azogui Y. Early and moderate sensory stimulation exerts a protective effect on perilesion representations of somatosensory cortex after focal ischemic damage. PLoS One 2014; 9:e99767. [PMID: 24914807 PMCID: PMC4051766 DOI: 10.1371/journal.pone.0099767] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/19/2014] [Indexed: 02/05/2023] Open
Abstract
Previous studies have shown that intensive training within an early critical time window after focal cortical ischemia increases the area of damaged tissue and is detrimental to behavioral recovery. We postulated that moderate stimulation initiated soon after the lesion could have protective effects on peri-infarct cortical somatotopic representations. Therefore, we have assessed the effects of mild cutaneous stimulation delivered in an attention-demanding behavioral context on the functional organization of the perilesion somatosensory cortex using high-density electrophysiological mapping. We compared the effects of 6-day training initiated on the 3rd day postlesion (early training; ET) to those of same-duration training started on the 8th day (delayed training; DT). Our findings confirm previous work showing that the absence of training aggravates representational loss in the perilesion zone. In addition, ET was found to be sufficient to limit expansion of the ischemic lesion and reduce tissue loss, and substantially maintain the neuronal responsiveness to tactile stimulation, thereby preserving somatotopic map arrangement in the peri-infarct cortical territories. By contrast, DT did not prevent tissue loss and only partially reinstated lost representations in a use-dependent manner within the spared peri-infarct cortical area. This study differentiates the effects of early versus delayed training on perilesion tissue and cortical map reorganization, and underscores the neuroprotective influence of mild rehabilitative stimulation on neuronal response properties in the peri-infarct cortex during an early critical period.
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Affiliation(s)
- Christian Xerri
- Neurosciences Intégratives et Adaptatives, Aix-Marseille Université, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7260, Fédération de Recherches Comportement-Cerveau-Cognition 3512, Marseille, France
- * E-mail:
| | - Yoh'i Zennou-Azogui
- Neurosciences Intégratives et Adaptatives, Aix-Marseille Université, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7260, Fédération de Recherches Comportement-Cerveau-Cognition 3512, Marseille, France
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Magnuson ME, Thompson GJ, Pan WJ, Keilholz SD. Time-dependent effects of isoflurane and dexmedetomidine on functional connectivity, spectral characteristics, and spatial distribution of spontaneous BOLD fluctuations. NMR Biomed 2014; 27:291-303. [PMID: 24449532 PMCID: PMC4465547 DOI: 10.1002/nbm.3062] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 11/17/2013] [Accepted: 11/22/2013] [Indexed: 05/05/2023]
Abstract
Anesthesia is often necessary to perform fMRI experiments in the rodent model; however, commonly used anesthetic protocols may manifest changing brain conditions over the duration of the study. This possibility was explored in the current work. Eleven rats were anesthetized with 2% isoflurane anesthesia; four rats were anesthetized for a short period (30 min, simulating induction and fMRI setup) and seven rats were anesthetized for a long period (3 h, simulating surgical preparation). Following the initial anesthetic period, isoflurane was discontinued, and a dexmedetomidine bolus (0.025 mg/kg) and continuous subcutaneous infusion (0.05 mg/kg/h) were administered. Blood-oxygen-level dependent resting state imaging was performed every 30 min from 0.75 h post dexmedetomidine bolus until 5.75 h post-bolus. Evaluation of power spectra obtained from time courses in the primary somatosensory cortex revealed, in general, a monotonic increase in low-frequency power (0.05-0.3 Hz) in both groups over the duration of resting state imaging. Greater low-band spectral power (0.05-0.15 Hz) is present in the short isoflurane group for the first 2.75 h, but the spectra become highly uniform at 3.25 h. The emergence of a ~0.18 Hz peak, beginning at the 3.75 h time point, exists in both groups and evolves similarly, increasing in strength as the duration of dexmedetomidine sedation (and time since isoflurane cessation) extends. In the long isoflurane group only, bilateral functional connectivity strengthens with anesthetic duration, and correlation is linearly linked to low-band spectral power. Convergence of connectivity and spectral metrics between the short and long isoflurane groups occurs at ~3.25 h, suggesting the effects of isoflurane have subsided. Researchers using dexmedetomidine following isoflurane for functional studies should be aware of the duration specific effects of the pre-scan isoflurane durations as well as the continuing influences of long-term imaging under dexmedetomidine.
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Affiliation(s)
| | | | - Wen-Ju Pan
- Correspondence to: W.-J. Pan and S. D. Keilholz, Georgia Institute of Technology and Emory University, Biomedical Engineering, Atlanta, GA, USA., ;
| | - Shella Dawn Keilholz
- Correspondence to: W.-J. Pan and S. D. Keilholz, Georgia Institute of Technology and Emory University, Biomedical Engineering, Atlanta, GA, USA., ;
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Staiger JF, Bojak I, Miceli S, Schubert D. A gradual depth-dependent change in connectivity features of supragranular pyramidal cells in rat barrel cortex. Brain Struct Funct 2014; 220:1317-37. [PMID: 24569853 PMCID: PMC4409644 DOI: 10.1007/s00429-014-0726-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 01/31/2014] [Indexed: 01/31/2023]
Abstract
Recent experimental evidence suggests a finer genetic, structural and functional subdivision of the layers which form a cortical column. The classical layer II/III (LII/III) of rodent neocortex integrates ascending sensory information with contextual cortical information for behavioral read-out. We systematically investigated to which extent regular-spiking supragranular pyramidal neurons, located at different depths within the cortex, show different input-output connectivity patterns. Combining glutamate uncaging with whole-cell recordings and biocytin filling, we revealed a novel cellular organization of LII/III: (1) "Lower LII/III" pyramidal cells receive a very strong excitatory input from lemniscal LIV and much fewer inputs from paralemniscal LVa. They project to all layers of the home column, including a feedback projection to LIV, whereas transcolumnar projections are relatively sparse. (2) "Upper LII/III" pyramidal cells also receive their strongest input from LIV, but in addition, a very strong and dense excitatory input from LVa. They project extensively to LII/III as well as LVa and Vb of their home and neighboring columns. (3) "Middle LII/III" pyramidal cell shows an intermediate connectivity phenotype that stands in many ways in between the features described for lower versus upper LII/III. "Lower LII/III" intracolumnarly segregates and transcolumnarly integrates lemniscal information, whereas "upper LII/III" seems to integrate lemniscal with paralemniscal information. This suggests a fine-grained functional subdivision of the supragranular compartment containing multiple circuits without any obvious cytoarchitectonic, other structural or functional correlate of a laminar border in rodent barrel cortex.
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Affiliation(s)
- Jochen F. Staiger
- Institute for Neuroanatomy, University Medicine Göttingen, Kreuzbergring 36, 37075 Göttingen, Germany
| | - Ingo Bojak
- School of Systems Engineering, University of Reading, PO Box 225, Whiteknights, Reading, Berkshire RG6 6AY UK
- Donders Institute for Brain, Cognition and Behavior, Centre for Neuroscience, Radboud University Nijmegen Medical Centre, POB 9101//126, 6500 HB Nijmegen, The Netherlands
| | - Stéphanie Miceli
- Donders Institute for Brain, Cognition and Behavior, Centre for Neuroscience, Radboud University Nijmegen Medical Centre, POB 9101//126, 6500 HB Nijmegen, The Netherlands
| | - Dirk Schubert
- Donders Institute for Brain, Cognition and Behavior, Centre for Neuroscience, Radboud University Nijmegen Medical Centre, POB 9101//126, 6500 HB Nijmegen, The Netherlands
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Li Z, Liu X, Zhang Y, Shi J, Zhang Y, Xie P, Yu T. Connection changes in somatosensory cortex induced by different doses of propofol. PLoS One 2014; 9:e87829. [PMID: 24516566 PMCID: PMC3917837 DOI: 10.1371/journal.pone.0087829] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/01/2014] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The mechanism by which general anesthetics, widely used in clinical practice for over 160 years, effects on sensory responsiveness has been unclear until now. In the present study, the authors sought to explore the effect of different doses of propofol on somatosensory cortex by whisker stimulation in rats. METHODS In a fixed cage, rats were anesthetized with propofol 80 mg/kg intraperitoneally and then cathetered tail vein with 23-gauge metal needle connected with a pump. Two holes (2 mm diameter) were drilled and recording electrodes implantated in the primary somatosensory cortex barrel field (S1BF) and secondary somatosensory cortex (S2). The extracellular (20 rats) and intracellular (8 rats) recordings were used to test the neuron activity in both cortices at different doses of propofol (20, 40 and 80 mg/kg/h) through tail vein by pump. Meantime, vibrissal, olfactory, corneal responses (VOCR, sedation), and tail-pinch response (TRP, analgesia) were tested every 10 min during the doses of propofol 20, 40 and 80 mg/kg/h. RESULTS VOCR and TRP were depressed by propofol in a dose-dependent manner. The amplitude by whisker stimulation in S1BF was stronger and the peak latency was shorter compared with that of in S2. The response latency of S1BF and S2 was increased by raising infusion rate of propofol with the response latency in S2 being longer than that in S1BF at the same doses of propofol. The cross-correlation between S1BF and S2 decreased as the propofol infusion rate increased. The input resistance was higher by increasing infusion rate of propofol. CONCLUSION The sedation and analgesia effects of propofol were dose-dependent. Both the connectivity and instinctive oscillation between S1BF and S2 were proportionally modulated by the different doses of propofol.
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Affiliation(s)
- Zhaoduan Li
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Xingkui Liu
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Yi Zhang
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Jinshan Shi
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Yu Zhang
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Peng Xie
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Tian Yu
- Department of Anesthesiology, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
- * E-mail:
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Zhang Y, Wang C, Zhang Y, Zhang L, Yu T. GABAA receptor in the thalamic specific relay system contributes to the propofol-induced somatosensory cortical suppression in rat. PLoS One 2013; 8:e82377. [PMID: 24324778 PMCID: PMC3853356 DOI: 10.1371/journal.pone.0082377] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/25/2013] [Indexed: 12/17/2022] Open
Abstract
Interaction with the gamma-aminobutyric-acid-type-A (GABAA) receptors is recognized as an important component of the mechanism of propofol, a sedative-hypnotic drug commonly used as anesthetic. However the contribution of GABAA receptors to the central nervous system suppression is still not well understood, especially in the thalamocortical network. In the present study, we investigated if intracerebral injection of bicuculline (a GABAA receptor antagonist) into the thalamus ventral posteromedial nucleus (VPM, a thalamus specific relay nuclei that innervated S1 mostly) could reverse propofol-induced cortical suppression, through recording the changes of both spontaneous and somatosensory neural activities in rat's somatosensory cortex (S1). We found that after injection of bicuculline into VPM, significant increase of neural activities were observed in all bands of local field potentials (total band, 182±6%), while the amplitude of all components in somatosensory evoked potentials were also increased (negative, 121±9% and positive, 124±6%).These data support that the potentiation of GABAA receptor-mediated synaptic inhibition in a thalamic specific relay system seems to play a crucial role in propofol-induced cortical suppression in the somatosensory cortex of rats.
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Affiliation(s)
- Yu Zhang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Chaoping Wang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Yi Zhang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Lin Zhang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Tian Yu
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
- * E-mail:
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Khan MM, Dhandapani KM, Zhang QG, Brann DW. Estrogen regulation of spine density and excitatory synapses in rat prefrontal and somatosensory cerebral cortex. Steroids 2013; 78:614-23. [PMID: 23276632 PMCID: PMC3640687 DOI: 10.1016/j.steroids.2012.12.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 11/28/2012] [Accepted: 12/03/2012] [Indexed: 11/28/2022]
Abstract
The steroid hormone, 17β-estradiol (E2) has been reported to enhance executive functions that are known to be mediated by the prefrontal cortex (PFC), although the underlying mechanisms remain unclear. To shed light on the potential mechanisms, we examined the effect of E2 in vivo upon spine density in the rat PFC and the somatosensory cortex (SSC), which has been implicated to be a transient storage site for information that can also contribute to working memory. The results revealed that E2 significantly enhanced the number of dendritic spines in both the SSC and PFC, as well as the expression of spinophilin. In vitro studies revealed further mechanistic insights by demonstrating that E2 enhanced AMPA GluR1 receptor expression and excitatory glutamatergic synapse formation in rat cortical neurons, without an effect upon inhibitory GABAergic synapse formation. Furthermore, E2 rapidly enhanced ERK and Akt activation in cortical neurons, and inhibitors of ERK and Akt activation significantly attenuated E2 induction of excitatory glutamatergic synapses. Administration of E2-BSA likewise significantly enhanced excitatory glutamatergic synapses in cortical neurons, and administration of an ER antagonist, ICI182,780 and a non-NMDA receptor antagonist (NBQX) significantly attenuated the effect of E2 upon enhancement of excitatory glutamatergic synapses, suggesting mediation by extranuclear estrogen receptors and involvement of non-NMDA receptor activation and signaling. As a whole, the studies demonstrate that E2 enhances spine density in both the PFC and SSC, and that E2 enhances excitatory glutamatergic synapse formation in cortical neurons via a rapid extranuclear ER-mediated signaling mechanism that involves up-regulation of GluR1 and mediation by Akt and ERK signaling pathways.
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Affiliation(s)
- Mohammad M. Khan
- Institute of Molecular Medicine and Genetics, Department of Neurology, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912
| | - Krishnan M. Dhandapani
- Department of Neurosurgery, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912
| | - Quan-guang Zhang
- Institute of Molecular Medicine and Genetics, Department of Neurology, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912
| | - Darrell W. Brann
- Institute of Molecular Medicine and Genetics, Department of Neurology, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912
- To Whom Correspondence should be addressed: Darrell W. Brann, Ph.D., Regents’ Professor and Director, Graduate Program in Neuroscience, Institute of Molecular Medicine and Genetics, and Department of Neurology, Georgia Health Sciences University, 1120 15th Street, Augusta, GA 30912, Phone: 706-721-7779, Fax: 706-721-8685,
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Granmo M, Jensen T, Schouenborg J. Nociceptive transmission to rat primary somatosensory cortex--comparison of sedative and analgesic effects. PLoS One 2013; 8:e53966. [PMID: 23320109 PMCID: PMC3540052 DOI: 10.1371/journal.pone.0053966] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 12/06/2012] [Indexed: 11/18/2022] Open
Abstract
CO(2)-laser C-fibre evoked cortical potentials (LCEPs) is a potentially useful animal model for studies of pain mechanisms. A potential confounding factor when assessing analgesic effects of systemically administered drugs using LCEP is sedation. This study aims to clarify: 1) the relation between level of anaesthesia and magnitude of LCEP, 2) the effects of a sedative and an analgesic on LCEP and dominant EEG frequency 3) the effects of a sedative and analgesic on LCEP when dominant EEG frequency is kept stable. LCEP and EEG were recorded in isoflurane/nitrous-oxide anaesthetized rats. Increasing isoflurane level gradually reduced LCEPs and lowered dominant EEG frequencies. Systemic midazolam (10 μmol/kg) profoundly reduced LCEP (19% of control) and lowered dominant EEG frequency. Similarly, morphine 1 and 3 mg/kg reduced LCEP (39%, 12% of control, respectively) and decreased EEG frequency. When keeping the dominant EEG frequency stable, midazolam caused no significant change of LCEP. Under these premises, morphine at 3 mg/kg, but not 1 mg/kg, caused a significant LCEP reduction (26% of control). In conclusion, the present data indicate that the sedative effects should be accounted for when assessing the analgesic effects of drug. Furthermore, it is suggested that LCEP, given that changes in EEG induced by sedation are compensated for, can provide information about the analgesic properties of systemically administrated drugs.
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Affiliation(s)
- Marcus Granmo
- Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden.
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44
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Shih AY, Blinder P, Tsai PS, Friedman B, Stanley G, Lyden PD, Kleinfeld D. The smallest stroke: occlusion of one penetrating vessel leads to infarction and a cognitive deficit. Nat Neurosci 2013; 16:55-63. [PMID: 23242312 PMCID: PMC3952571 DOI: 10.1038/nn.3278] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/15/2012] [Indexed: 11/09/2022]
Abstract
Microinfarctions are present in the aged and injured human brain. Their clinical relevance is controversial, with postulated sequelae ranging from cognitive sparing to vascular dementia. To address the consequences of microinfarcts, we used controlled optical methods to create occlusions of individual penetrating arterioles or venules in rat cortex. Single microinfarcts, targeted to encompass all or part of a cortical column, impaired performance in a macrovibrissa-based behavioral task. Furthermore, the targeting of multiple vessels resulted in tissue damage that coalesced across cortex, even though the intervening penetrating vessels were acutely patent. Post-occlusion administration of memantine, a glutamate receptor antagonist that reduces cognitive decline in Alzheimer's disease, ameliorated tissue damage and perceptual deficits. Collectively, these data imply that microinfarcts likely contribute to cognitive decline. Strategies that have received limited success in the treatment of ischemic injury, which include therapeutics against excitotoxicity, may be successful against the progressive nature of vascular dementia.
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Affiliation(s)
- Andy Y. Shih
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Pablo Blinder
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Philbert S. Tsai
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Beth Friedman
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, USA
| | - Geoffrey Stanley
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Patrick D. Lyden
- Department of Neurology, Cedars-Sinai Hospital, Los Angeles, CA, USA
| | - David Kleinfeld
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
- Section of Neurobiology, University of California at San Diego, La Jolla, CA, USA
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45
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Abstract
A single 17β-oestradiol (E(2)) treatment reduces the loss in cholinergic fibre density in the cortex after NMDA lesion into the nucleus basalis magnocellularis (NBM) of the basal forebrain (BF) in young female mice. In the present study, we examined whether age influences this protective effect of E(2) on cholinergic neurones in male and female mice. Gonad-intact young and aged animals of both sexes were treated with E(2) after unilateral NMDA lesion into the NBM. NMDA lesion elicited ipsilateral cholinergic cell loss in the NBM and ipsilateral fibre loss in the somatosensory cortex to the same extent, irrespective of age or sex. A single E(2) injection performed 1 h post-lesion did not affect the cholinergic cell loss but reduced the loss of fibres in the ipsilateral cortex in young male and female mice. By contrast, E(2) did not have an effect on the NMDA-induced cholinergic cell and fibre loss in aged male or female mice. The oestrous stage of young female mice did not alter the number of cholinergic cells/fibres or the protective effect of E(2) on cholinergic fibres after NMDA injection. Our results show that E(2) has a protective action on BF cholinergic fibres in young males and females, although the treatment potential of E(2) declines with age.
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Affiliation(s)
- Z Kőszegi
- Centre for Neuroendocrinology and Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
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46
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Ying SW, Kanda VA, Hu Z, Purtell K, King EC, Abbott GW, Goldstein PA. Targeted deletion of Kcne2 impairs HCN channel function in mouse thalamocortical circuits. PLoS One 2012; 7:e42756. [PMID: 22880098 PMCID: PMC3411840 DOI: 10.1371/journal.pone.0042756] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/12/2012] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels generate the pacemaking current, I(h), which regulates neuronal excitability, burst firing activity, rhythmogenesis, and synaptic integration. The physiological consequence of HCN activation depends on regulation of channel gating by endogenous modulators and stabilization of the channel complex formed by principal and ancillary subunits. KCNE2 is a voltage-gated potassium channel ancillary subunit that also regulates heterologously expressed HCN channels; whether KCNE2 regulates neuronal HCN channel function is unknown. METHODOLOGY/PRINCIPAL FINDINGS We investigated the effects of Kcne2 gene deletion on I(h) properties and excitability in ventrobasal (VB) and cortical layer 6 pyramidal neurons using brain slices prepared from Kcne2(+/+) and Kcne2(-/-) mice. Kcne2 deletion shifted the voltage-dependence of I(h) activation to more hyperpolarized potentials, slowed gating kinetics, and decreased I(h) density. Kcne2 deletion was associated with a reduction in whole-brain expression of both HCN1 and HCN2 (but not HCN4), although co-immunoprecipitation from whole-brain lysates failed to detect interaction of KCNE2 with HCN1 or 2. Kcne2 deletion also increased input resistance and temporal summation of subthreshold voltage responses; this increased intrinsic excitability enhanced burst firing in response to 4-aminopyridine. Burst duration increased in corticothalamic, but not thalamocortical, neurons, suggesting enhanced cortical excitatory input to the thalamus; such augmented excitability did not result from changes in glutamate release machinery since miniature EPSC frequency was unaltered in Kcne2(-/-) neurons. CONCLUSIONS/SIGNIFICANCE Loss of KCNE2 leads to downregulation of HCN channel function associated with increased excitability in neurons in the cortico-thalamo-cortical loop. Such findings further our understanding of the normal physiology of brain circuitry critically involved in cognition and have implications for our understanding of various disorders of consciousness.
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Affiliation(s)
- Shui-Wang Ying
- Department of Anesthesiology, Weill Cornell Medical College, New York, New York, United States of America
| | - Vikram A. Kanda
- Department of Pharmacology, Weill Cornell Medical College, New York, New York, United States of America
| | - Zhaoyang Hu
- Departments of Pharmacology, and Physiology and Biophysics, University of California Irvine, Irvine, California, United States of America
| | - Kerry Purtell
- Department of Pharmacology, Weill Cornell Medical College, New York, New York, United States of America
| | - Elizabeth C. King
- Department of Pharmacology, Weill Cornell Medical College, New York, New York, United States of America
| | - Geoffrey W. Abbott
- Departments of Pharmacology, and Physiology and Biophysics, University of California Irvine, Irvine, California, United States of America
| | - Peter A. Goldstein
- Department of Anesthesiology, Weill Cornell Medical College, New York, New York, United States of America
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Diukova A, Ware J, Smith JE, Evans CJ, Murphy K, Rogers PJ, Wise RG. Separating neural and vascular effects of caffeine using simultaneous EEG-FMRI: differential effects of caffeine on cognitive and sensorimotor brain responses. Neuroimage 2012; 62:239-49. [PMID: 22561357 PMCID: PMC3778750 DOI: 10.1016/j.neuroimage.2012.04.041] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 04/16/2012] [Accepted: 04/21/2012] [Indexed: 11/27/2022] Open
Abstract
The effects of caffeine are mediated through its non-selective antagonistic effects on adenosine A(1) and A(2A) adenosine receptors resulting in increased neuronal activity but also vasoconstriction in the brain. Caffeine, therefore, can modify BOLD FMRI signal responses through both its neural and its vascular effects depending on receptor distributions in different brain regions. In this study we aim to distinguish neural and vascular influences of a single dose of caffeine in measurements of task-related brain activity using simultaneous EEG-FMRI. We chose to compare low-level visual and motor (paced finger tapping) tasks with a cognitive (auditory oddball) task, with the expectation that caffeine would differentially affect brain responses in relation to these tasks. To avoid the influence of chronic caffeine intake, we examined the effect of 250 mg of oral caffeine on 14 non and infrequent caffeine consumers in a double-blind placebo-controlled cross-over study. Our results show that the task-related BOLD signal change in visual and primary motor cortex was significantly reduced by caffeine, while the amplitude and latency of visual evoked potentials over occipital cortex remained unaltered. However, during the auditory oddball task (target versus non-target stimuli) caffeine significantly increased the BOLD signal in frontal cortex. Correspondingly, there was also a significant effect of caffeine in reducing the target evoked response potential (P300) latency in the oddball task and this was associated with a positive potential over frontal cortex. Behavioural data showed that caffeine also improved performance in the oddball task with a significantly reduced number of missed responses. Our results are consistent with earlier studies demonstrating altered flow-metabolism coupling after caffeine administration in the context of our observation of a generalised caffeine-induced reduction in cerebral blood flow demonstrated by arterial spin labelling (19% reduction over grey matter). We were able to identify vascular effects and hence altered neurovascular coupling through the alteration of low-level task FMRI responses in the face of a preserved visual evoked potential. However, our data also suggest a cognitive effect of caffeine through its positive effect on the frontal BOLD signal consistent with the shortening of oddball EEG response latency. The combined use of EEG-FMRI is a promising methodology for investigating alterations in brain function in drug and disease studies where neurovascular coupling may be altered on a regional basis.
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Affiliation(s)
- Ana Diukova
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Jennifer Ware
- Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Jessica E. Smith
- Department of Experimental Psychology, University of Bristol, Bristol, UK
| | - C. John Evans
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Kevin Murphy
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Peter J. Rogers
- Department of Experimental Psychology, University of Bristol, Bristol, UK
| | - Richard G. Wise
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
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48
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Matukhno AE, Sukhov AG, Sinitsyna VV. [The role of GABAA and GABAB receptors in formation of evoked potentials in the barrel cortex of rats]. Zh Vyssh Nerv Deiat Im I P Pavlova 2012; 62:372-382. [PMID: 22891583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
By means of local microapplication of GABA, picrotoxin and CGP 52432, different roles of GABAA and GABAB receptors in the geneses of primary and secondary components of evoked potentials in the somatosensory barrel cortex of rats were shown. The authors conclude that the aftereffect rhythmical components of the evoked potentials are caused by the local pacemaker mechanisms based on endogene properties of barrel neurons.
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49
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Abstract
In the mammalian CNS, the expression of neuronal gap junction protein, connexin 36 (Cx36), increases during the first 2 weeks of postnatal development and then decreases during the following 2 weeks. Recently we showed that the developmental increase in Cx36 expression is augmented by chronic (2 weeks) activation of group II metabotropic glutamate receptors (mGluR), prevented by chronic receptor inactivation, and the receptor-dependent increase in Cx36 expression is regulated via transcriptional control of the Cx36 gene activity. We demonstrate here that acute (60 min) activation of group II mGluRs in developing cortical neuronal cultures causes transient increase in Cx36 protein expression with decrease during the following 24h. However, there is no change in Cx36 mRNA expression. In addition, the data indicate that transient increase in Cx36 expression is due to new protein synthesis. The results suggest that, during development, acute activation of group II mGluRs causes up-regulation of Cx36 via post-transcriptional mechanisms. However, if the receptor activation is sustained, transcriptional activation of the Cx36 gene occurs.
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Affiliation(s)
- Ji-Hoon Song
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Yongfu Wang
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Joseph D. Fontes
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Andrei B. Belousov
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Turner CP, Gutierrez S, Liu C, Miller L, Chou J, Finucane B, Carnes A, Kim J, Shing E, Haddad T, Phillips A. Strategies to defeat ketamine-induced neonatal brain injury. Neuroscience 2012; 210:384-92. [PMID: 22406413 DOI: 10.1016/j.neuroscience.2012.02.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 02/03/2012] [Accepted: 02/07/2012] [Indexed: 11/19/2022]
Abstract
Studies using animal models have shown that general anesthetics such as ketamine trigger widespread and robust apoptosis in the infant rodent brain. Recent clinical evidence suggests that the use of general anesthetics on young children (at ages equivalent to those used in rodent studies) can promote learning deficits as they mature. Thus, there is a growing need to develop strategies to prevent this injury. In this study, we describe a number of independent approaches to address therapeutic intervention. Postnatal day 7 (P7) rats were injected with vehicle (sterile PBS) or the NMDAR antagonist ketamine (20 mg/kg). After 8 h, we prepared brains for immunohistochemical detection of the pro-apoptotic enzyme activated caspase-3 (AC3). Focusing on the somatosensory cortex, AC3-positive cells were then counted in a non-biased stereological manner. We found AC3 levels were markedly increased in ketamine-treated animals. In one study, microarray analysis of the somatosensory cortex from ketamine-treated P7 pups revealed that expression of activity dependent neuroprotective protein (ADNP) was enhanced. Thus, we injected P7 animals with the ADNP peptide fragment NAPVSIPQ (NAP) 15 min before ketamine administration and found we could dose-dependently reverse the injury. In separate studies, pretreatment of P6 animals with 20 mg/kg vitamin D(3) or a nontoxic dose of ketamine (5 mg/kg) also prevented ketamine-induced apoptosis at P7. In contrast, pretreatment of P7 animals with aspirin (30 mg/kg) 15 min before ketamine administration actually increased AC3 counts in some regions. These data show that a number of unique approaches can be taken to address anesthesia-induced neurotoxicity in the infant brain, thus providing MDs with a variety of alternative strategies that enhance therapeutic flexibility.
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Affiliation(s)
- C P Turner
- Neurobiology & Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1010, USA.
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