1
|
Hidisoglu E, Chiantia G, Franchino C, Tomagra G, Giustetto M, Carbone E, Carabelli V, Marcantoni A. The ryanodine receptor-calstabin interaction stabilizer S107 protects hippocampal neurons from GABAergic synaptic alterations induced by Abeta42 oligomers. J Physiol 2022; 600:5295-5309. [PMID: 36284365 DOI: 10.1113/jp283537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/12/2022] [Indexed: 01/05/2023] Open
Abstract
The oligomeric form of the peptide amyloid beta 42 (Abeta42) contributes to the development of synaptic abnormalities and cognitive impairments associated with Alzheimer's disease (AD). To date, there is a gap in knowledge regarding how Abeta42 alters the elementary parameters of GABAergic synaptic function. Here we found that Abeta42 increased the frequency and amplitude of miniature GABAergic currents as well as the amplitude of evoked inhibitory postsynaptic currents. When we focused on paired pulse depression (PPD) to establish whether GABA release probability was affected by Abeta42, we did not observe any significant change. On the other hand, a more detailed investigation of the presynaptic effects induced by Abeta42 by means of multiple probability fluctuation analysis and cumulative amplitude analysis showed an increase in both the size of the readily releasable pool responsible for synchronous release and the number of release sites. We further explored whether ryanodine receptors (RyRs) contributed to exacerbating these changes by stabilizing the interaction between RyRs and the accessory protein calstabin. We observed that the RyR-calstabin interaction stabilizer S107 restored the synaptic parameters to values comparable to those measured in control conditions. In conclusion, our results clarify the mechanisms of potentiation of GABAergic synapses induced by Abeta42. We further suggest that RyRs are involved in the control of synaptic activity during the early stage of AD onset and that their stabilization could represent a new therapeutical approach for AD treatment. KEY POINTS: Accumulation of the peptide amyloid beta 42 (Abeta42) is a key characteristic of Alzheimer's disease (AD) and causes synaptic dysfunctions. To date, the effects of Abeta42 accumulation on GABAergic synapses are poorly understood. The findings reported here suggest that, similarly to what is observed on glutamatergic synapses, Abeta42 modifies GABAergic synapses by targeting ryanodine receptors and causing calcium dysregulation. The GABAergic impairments can be restored by the ryanodine receptor-calstabin interaction stabilizer S107. Based on this research, RyRs stabilization may represent a novel pharmaceutical strategy for preventing or delaying AD.
Collapse
Affiliation(s)
- Enis Hidisoglu
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | | | - Claudio Franchino
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Giulia Tomagra
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | | | - Emilio Carbone
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Valentina Carabelli
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Andrea Marcantoni
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| |
Collapse
|
2
|
Van Hook MJ. Brain-derived neurotrophic factor is a regulator of synaptic transmission in the adult visual thalamus. J Neurophysiol 2022; 128:1267-1277. [PMID: 36224192 PMCID: PMC9662800 DOI: 10.1152/jn.00540.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 10/12/2022] [Accepted: 10/12/2022] [Indexed: 11/22/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is an important regulator of circuit development, neuronal survival, and plasticity throughout the nervous system. In the visual system, BDNF is produced by retinal ganglion cells (RGCs) and transported along their axons to central targets. Within the dorsolateral geniculate nucleus (dLGN), a key RGC projection target for conscious vision, the BDNF receptor tropomyosin receptor kinase B (TrkB) is present on RGC axon terminals and postsynaptic thalamocortical (TC) relay neuron dendrites. Based on this, the goal of this study was to determine how BDNF modulates the conveyance of signals through the retinogeniculate (RG) pathway of adult mice. Application of BDNF to dLGN brain slices increased TC neuron spiking evoked by optogenetic stimulation of RGC axons. There was a modest contribution to this effect from a BDNF-dependent enhancement of TC neuron intrinsic excitability including increased input resistance and membrane depolarization. BDNF also increased evoked vesicle release from RGC axon terminals, as evidenced by increased amplitude of evoked excitatory postsynaptic currents (EPSCs), which was blocked by inhibition of TrkB or phospholipase C. High-frequency stimulation revealed that BDNF increased synaptic vesicle pool size, release probability, and replenishment rate. There was no effect of BDNF on EPSC amplitude or short-term plasticity of corticothalamic feedback synapses. Thus, BDNF regulates RG synapses by both presynaptic and postsynaptic mechanisms. These findings suggest that BNDF influences the flow of visual information through the retinogeniculate pathway.NEW & NOTEWORTHY Brain-derived neurotrophic factor (BDNF) is an important regulator of neuronal development and plasticity. In the visual system, BDNF is transported along retinal ganglion cell (RGC) axons to the dorsolateral geniculate nucleus (dLGN), although it is not known how it influences mature dLGN function. Here, BDNF enhanced thalamocortical relay neuron responses to signals arising from RGC axons in the dLGN, pointing toward an important role for BDNF in processing signals en route to the visual cortex.
Collapse
Affiliation(s)
- Matthew J Van Hook
- Truhlsen Eye Institute, Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| |
Collapse
|
3
|
Siller A, Hofer NT, Tomagra G, Burkert N, Hess S, Benkert J, Gaifullina A, Spaich D, Duda J, Poetschke C, Vilusic K, Fritz EM, Schneider T, Kloppenburg P, Liss B, Carabelli V, Carbone E, Ortner NJ, Striessnig J. β2-subunit alternative splicing stabilizes Cav2.3 Ca 2+ channel activity during continuous midbrain dopamine neuron-like activity. eLife 2022; 11:e67464. [PMID: 35792082 PMCID: PMC9307272 DOI: 10.7554/elife.67464] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
In dopaminergic (DA) Substantia nigra (SN) neurons Cav2.3 R-type Ca2+-currents contribute to somatodendritic Ca2+-oscillations. This activity may contribute to the selective degeneration of these neurons in Parkinson's disease (PD) since Cav2.3-knockout is neuroprotective in a PD mouse model. Here, we show that in tsA-201-cells the membrane-anchored β2-splice variants β2a and β2e are required to stabilize Cav2.3 gating properties allowing sustained Cav2.3 availability during simulated pacemaking and enhanced Ca2+-currents during bursts. We confirmed the expression of β2a- and β2e-subunit transcripts in the mouse SN and in identified SN DA neurons. Patch-clamp recordings of mouse DA midbrain neurons in culture and SN DA neurons in brain slices revealed SNX-482-sensitive R-type Ca2+-currents with voltage-dependent gating properties that suggest modulation by β2a- and/or β2e-subunits. Thus, β-subunit alternative splicing may prevent a fraction of Cav2.3 channels from inactivation in continuously active, highly vulnerable SN DA neurons, thereby also supporting Ca2+ signals contributing to the (patho)physiological role of Cav2.3 channels in PD.
Collapse
Affiliation(s)
- Anita Siller
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Nadja T Hofer
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Giulia Tomagra
- Department of Drug Science, NIS Centre, University of TorinoTorinoItaly
| | - Nicole Burkert
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Simon Hess
- Institute for Zoology, Biocenter, University of CologneCologneGermany
| | - Julia Benkert
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Aisylu Gaifullina
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Desiree Spaich
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Johanna Duda
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | | | - Kristina Vilusic
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Eva Maria Fritz
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Toni Schneider
- Institute of Neurophysiology, University of CologneCologneGermany
| | - Peter Kloppenburg
- Institute for Zoology, Biocenter, University of CologneCologneGermany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
- Linacre College & New College, University of OxfordOxfordUnited Kingdom
| | | | - Emilio Carbone
- Department of Drug Science, NIS Centre, University of TorinoTorinoItaly
| | - Nadine Jasmin Ortner
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| |
Collapse
|
4
|
Chronic partial TrkB activation reduces seizures and mortality in a mouse model of Dravet syndrome. Proc Natl Acad Sci U S A 2022; 119:2022726119. [PMID: 35165147 PMCID: PMC8851461 DOI: 10.1073/pnas.2022726119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2021] [Indexed: 12/03/2022] Open
Abstract
Dravet syndrome (DS) is a severe childhood epileptic encephalopathy characterized by intractable seizures and comorbidities, including a high rate of premature mortality. DS is mainly caused by loss-of-function mutations of the Scn1a gene encoding sodium channel Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, causing DS phenotypes. Effective pharmacological therapy targeting defective PV interneurons is currently not available. This study demonstrated that early treatment with a partial TrkB receptor agonist, LM22A-4, increased Nav1.1 expression, improved PV interneuron function, and reduced seizure occurrence and mortality rate in DS mice, suggesting a potential therapy for DS. Dravet syndrome (DS) is one of the most severe childhood epilepsies, characterized by intractable seizures and comorbidities including cognitive and social dysfunction and high premature mortality. DS is mainly caused by loss-of-function mutations in the Scn1a gene encoding Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, contributing to DS phenotypes. Effective pharmacological therapy that targets defective PV interneurons is not available. The known role of brain-derived neurotrophic factor (BDNF) in the development and maintenance of interneurons, together with our previous results showing improved PV interneuronal function and antiepileptogenic effects of a TrkB receptor agonist in a posttraumatic epilepsy model, led to the hypothesis that early treatment with a TrkB receptor agonist might prevent or reduce seizure activity in DS mice. To test this hypothesis, we treated DS mice with LM22A-4 (LM), a partial agonist at the BDNF TrkB receptor, for 7 d starting at postnatal day 13 (P13), before the onset of spontaneous seizures. Results from immunohistochemistry, Western blot, whole-cell patch-clamp recording, and in vivo seizure monitoring showed that LM treatment increased the number of perisomatic PV interneuronal synapses around cortical pyramidal cells in layer V, upregulated Nav1.1 in PV neurons, increased inhibitory synaptic transmission, and decreased seizures and the mortality rate in DS mice. The results suggest that early treatment with a partial TrkB receptor agonist may be a promising therapeutic approach to enhance PV interneuron function and reduce epileptogenesis and premature death in DS.
Collapse
|
5
|
Prestigio C, Ferrante D, Marte A, Romei A, Lignani G, Onofri F, Valente P, Benfenati F, Baldelli P. REST/NRSF drives homeostatic plasticity of inhibitory synapses in a target-dependent fashion. eLife 2021; 10:e69058. [PMID: 34855580 PMCID: PMC8639147 DOI: 10.7554/elife.69058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 11/22/2021] [Indexed: 12/31/2022] Open
Abstract
The repressor-element 1-silencing transcription/neuron-restrictive silencer factor (REST/NRSF) controls hundreds of neuron-specific genes. We showed that REST/NRSF downregulates glutamatergic transmission in response to hyperactivity, thus contributing to neuronal homeostasis. However, whether GABAergic transmission is also implicated in the homeostatic action of REST/NRSF is unknown. Here, we show that hyperactivity-induced REST/NRSF activation, triggers a homeostatic rearrangement of GABAergic inhibition, with increased frequency of miniature inhibitory postsynaptic currents (IPSCs) and amplitude of evoked IPSCs in mouse cultured hippocampal neurons. Notably, this effect is limited to inhibitory-onto-excitatory neuron synapses, whose density increases at somatic level and decreases in dendritic regions, demonstrating a complex target- and area-selectivity. The upscaling of perisomatic inhibition was occluded by TrkB receptor inhibition and resulted from a coordinated and sequential activation of the Npas4 and Bdnf gene programs. On the opposite, the downscaling of dendritic inhibition was REST-dependent, but BDNF-independent. The findings highlight the central role of REST/NRSF in the complex transcriptional responses aimed at rescuing physiological levels of network activity in front of the ever-changing environment.
Collapse
Affiliation(s)
- Cosimo Prestigio
- Department of Experimental Medicine, University of GenovaGenovaItaly
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
| | - Daniele Ferrante
- Department of Experimental Medicine, University of GenovaGenovaItaly
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
| | - Antonella Marte
- Department of Experimental Medicine, University of GenovaGenovaItaly
| | - Alessandra Romei
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square HouseLondonUnited Kingdom
| | - Franco Onofri
- Department of Experimental Medicine, University of GenovaGenovaItaly
- IRCCS, Ospedale Policlinico San MartinoGenovaItaly
| | - Pierluigi Valente
- Department of Experimental Medicine, University of GenovaGenovaItaly
- IRCCS, Ospedale Policlinico San MartinoGenovaItaly
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- IRCCS, Ospedale Policlinico San MartinoGenovaItaly
| | - Pietro Baldelli
- Department of Experimental Medicine, University of GenovaGenovaItaly
- IRCCS, Ospedale Policlinico San MartinoGenovaItaly
| |
Collapse
|
6
|
Cash RFH, Udupa K, Gunraj CA, Mazzella F, Daskalakis ZJ, Wong AHC, Kennedy JL, Chen R. Influence of BDNF Val66Met polymorphism on excitatory-inhibitory balance and plasticity in human motor cortex. Clin Neurophysiol 2021; 132:2827-2839. [PMID: 34592560 DOI: 10.1016/j.clinph.2021.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/30/2021] [Accepted: 07/27/2021] [Indexed: 01/23/2023]
Abstract
OBJECTIVE While previous studies showed that the single nucleotide polymorphism (Val66Met) of brain-derived neurotrophic factor (BDNF) can impact neuroplasticity, the influence of BDNF genotype on cortical circuitry and relationship to neuroplasticity remain relatively unexplored in human. METHODS Using individualised transcranial magnetic stimulation (TMS) parameters, we explored the influence of the BDNF Val66Met polymorphism on excitatory and inhibitory neural circuitry, its relation to I-wave TMS (ITMS) plasticity and effect on the excitatory/inhibitory (E/I) balance in 18 healthy individuals. RESULTS Excitatory and inhibitory indexes of neurotransmission were reduced in Met allele carriers. An E/I balance was evident, which was influenced by BDNF with higher E/I ratios in Val/Val homozygotes. Both long-term potentiation (LTP-) and depression (LTD-) like ITMS plasticity were greater in Val/Val homozygotes. LTP- but not LTD-like effects were restored in Met allele carriers by increasing stimulus intensity to compensate for reduced excitatory transmission. CONCLUSIONS The influence of BDNF genotype may extend beyond neuroplasticity to neurotransmission. The E/I balance was evident in human motor cortex, modulated by BDNF and measurable using TMS. Given the limited sample, these preliminary findings warrant further investigation. SIGNIFICANCE These novel findings suggest a broader role of BDNF genotype on neurocircuitry in human motor cortex.
Collapse
Affiliation(s)
- R F H Cash
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Brain Institute, Toronto, Ontario, Canada; Melbourne Neuropsychiatry Centre, The University of Melbourne, Victoria 3010, Australia; Department of Biomedical Engineering, The University of Melbourne, Victoria 3010, Australia.
| | - K Udupa
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Brain Institute, Toronto, Ontario, Canada; Dept of Neurophysiology, NIMHANS, Bengaluru, India
| | - C A Gunraj
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Brain Institute, Toronto, Ontario, Canada
| | - F Mazzella
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Brain Institute, Toronto, Ontario, Canada
| | - Z J Daskalakis
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, UC San Diego Health, San Diego, CA 92093, USA
| | - A H C Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - J L Kennedy
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - R Chen
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Brain Institute, Toronto, Ontario, Canada
| |
Collapse
|
7
|
Ferrante D, Sterlini B, Prestigio C, Marte A, Corradi A, Onofri F, Tortarolo G, Vicidomini G, Petretto A, Muià J, Thalhammer A, Valente P, Cingolani LA, Benfenati F, Baldelli P. PRRT2 modulates presynaptic Ca 2+ influx by interacting with P/Q-type channels. Cell Rep 2021; 35:109248. [PMID: 34133925 PMCID: PMC8220258 DOI: 10.1016/j.celrep.2021.109248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 04/07/2021] [Accepted: 05/24/2021] [Indexed: 12/28/2022] Open
Abstract
Loss-of-function mutations in proline-rich transmembrane protein-2 (PRRT2) cause paroxysmal disorders associated with defective Ca2+ dependence of glutamatergic transmission. We find that either acute or constitutive PRRT2 deletion induces a significant decrease in the amplitude of evoked excitatory postsynaptic currents (eEPSCs) that is insensitive to extracellular Ca2+ and associated with a reduced contribution of P/Q-type Ca2+ channels to the EPSC amplitude. This synaptic phenotype parallels a decrease in somatic P/Q-type Ca2+ currents due to a decreased membrane targeting of the channel with unchanged total expression levels. Co-immunoprecipitation, pull-down assays, and proteomics reveal a specific and direct interaction of PRRT2 with P/Q-type Ca2+ channels. At presynaptic terminals lacking PRRT2, P/Q-type Ca2+ channels reduce their clustering at the active zone, with a corresponding decrease in the P/Q-dependent presynaptic Ca2+ signal. The data highlight the central role of PRRT2 in ensuring the physiological Ca2+ sensitivity of the release machinery at glutamatergic synapses.
Collapse
Affiliation(s)
- Daniele Ferrante
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Cosimo Prestigio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Franco Onofri
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Giorgio Tortarolo
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via Enrico Melen, 83B, 16152, Genova, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via Enrico Melen, 83B, 16152, Genova, Italy
| | - Andrea Petretto
- Core Facilities-Clinical Proteomics and Metabolomics, IRCCS, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
| | - Jessica Muià
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
| |
Collapse
|
8
|
Cho I, Kim JM, Kim EJ, Kim SY, Kam EH, Cheong E, Suh M, Koo BN. Orthopedic surgery-induced cognitive dysfunction is mediated by CX3CL1/R1 signaling. J Neuroinflammation 2021; 18:93. [PMID: 33858422 PMCID: PMC8048361 DOI: 10.1186/s12974-021-02150-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/05/2021] [Indexed: 12/31/2022] Open
Abstract
Background Postoperative pain is a common phenomenon after surgery and is closely associated with the development of postoperative cognitive dysfunction (POCD). Persistent pain and systemic inflammation caused by surgery have been suggested as key factors for the development of POCD. Fractalkine (CX3CL1) and its receptor, the CX3C chemokine receptor 1 (CX3CR1), are known to play a key role in pain and inflammation signaling pathways. Recent studies have shown that the regulation of CX3CR1/L1 signaling influences the development of various diseases including neuronal diseases. We determined whether CX3CR1/L1 signaling is a putative therapeutic target for POCD in a mouse model. Methods Adult (9–11 weeks) male mice were treated with neutralizing antibody to block CX3CR1/L1 signaling both before and after surgery. Inflammatory and behavioral responses including pain were assessed postoperatively. Also, CX3CR1 mRNA level was assessed. Hippocampal astrocyte activation, Mao B expression, and GABA expression were assessed at 2 days after surgery following neutralizing antibody administration. Results The behavioral response indicated cognitive dysfunction and development of pain in the surgery group compared with the control group. Also, increased levels of pro-inflammatory cytokines and CX3CR1 mRNA were observed in the surgery group. In addition, increased levels of GABA and increased Mao B expression were observed in reactive astrocytes in the surgery group; these responses were attenuated by neutralizing antibody administration. Conclusions Increased CX3CR1 after surgery is both necessary and sufficient to induce cognitive dysfunction. CX3CR1 could be an important target for therapeutic strategies to prevent the development of POCD. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02150-x.
Collapse
Affiliation(s)
- Inja Cho
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jeong Min Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Jung Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - So Yeon Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Hee Kam
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Minah Suh
- Department of Biomedical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeong gi-do, 16419, Republic of Korea.,Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon, 16419, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon, 16419, South Korea
| | - Bon-Nyeo Koo
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea. .,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
| |
Collapse
|
9
|
Pham MV, Miyaguchi S, Watanabe H, Saito K, Otsuru N, Onishi H. Effect of Repetitive Passive Movement Before Motor Skill Training on Corticospinal Excitability and Motor Learning Depend on BDNF Polymorphisms. Front Hum Neurosci 2021; 15:621358. [PMID: 33633556 PMCID: PMC7901944 DOI: 10.3389/fnhum.2021.621358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
A decrease in cortical excitability tends to be easily followed by an increase induced by external stimuli via a mechanism aimed at restoring it; this phenomenon is called “homeostatic plasticity.” In recent years, although intervention methods aimed at promoting motor learning using this phenomenon have been studied, an optimal intervention method has not been established. In the present study, we examined whether subsequent motor learning can be promoted further by a repetitive passive movement, which reduces the excitability of the primary motor cortex (M1) before motor learning tasks. We also examined the relationship between motor learning and the brain-derived neurotrophic factor. Forty healthy subjects (Val/Val genotype, 17 subjects; Met carrier genotype, 23 subjects) participated. Subjects were divided into two groups of 20 individuals each. The first group was assigned to perform the motor learning task after an intervention consisting in the passive adduction–abduction movement of the right index finger at 5 Hz for 10 min (RPM condition), while the second group was assigned to perform the task without the passive movement (control condition). The motor learning task consisted in the visual tracking of the right index finger. The results showed that the corticospinal excitability was transiently reduced after the passive movement in the RPM condition, whereas it was increased to the level detected in the control condition after the motor learning task. Furthermore, the motor learning ability was decreased immediately after the passive movement; however, the motor performance finally improved to the level observed in the control condition. In individuals carrying the Val/Val genotype, higher motor learning was also found to be related to the more remarkable changes in corticospinal excitability caused by the RPM condition. This study revealed that the implementation of a passive movement before a motor learning tasks did not affect M1 excitatory changes and motor learning efficiency; in contrast, in subjects carrying the Val/Val polymorphism, the more significant excitatory changes in the M1 induced by the passive movement and motor learning task led to the improvement of motor learning efficiency. Our results also suggest that homeostatic plasticity occurring in the M1 is involved in this improvement.
Collapse
Affiliation(s)
- Manh Van Pham
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Graduate School, Niigata University of Health and Welfare, Niigata, Japan.,Department of Physical Therapy, Hai Duong Medical Technical University, Hai Duong, Vietnam
| | - Shota Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan
| | - Hiraku Watanabe
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Graduate School, Niigata University of Health and Welfare, Niigata, Japan
| | - Kei Saito
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan
| | - Naofumi Otsuru
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.,Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan
| |
Collapse
|
10
|
Griego E, Herrera-López G, Gómez-Lira G, Barrionuevo G, Gutiérrez R, Galván EJ. Functional expression of TrkB receptors on interneurones and pyramidal cells of area CA3 of the rat hippocampus. Neuropharmacology 2020; 182:108379. [PMID: 33130041 DOI: 10.1016/j.neuropharm.2020.108379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/09/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022]
Abstract
The dentate gyrus and hippocampal area CA3 region of the mammalian brain contains the highest levels of brain-derived neurotrophic factor (BDNF) and its canonical membrane receptor, tropomyosin-related kinase B (TrkB). Therefore, the present study examines the expression and physiological responses triggered by activation of TrkB on hippocampal area CA3 interneurones and pyramidal cells of the rat hippocampus. Triple immunolabelling for TrkB, glutamate decarboxylase 67, and the calcium-binding proteins parvalbumin, calbindin or calretinin confirms the somatic expression of TrkB in all CA3 sublayers. TrkB-positive interneurones with fast-spiking discharge are restricted to strata oriens and lucidum, whereas regular-spiking interneurones are found in the strata lucidum, radiatum and lacunosum-moleculare. Activation of TrkB receptors with 7,8-dihydroxyflavone (DHF) modulates amplitude and frequency of spontaneous synaptic currents recorded from CA3 interneurones. Furthermore, the isolated excitatory postsynaptic currents (EPSC) of CA3 interneurones evoked by the mossy fibres (MF) or commissural/associational (C/A) axons, show input-specific synaptic potentiation in response to TrkB stimulation. On CA3 pyramidal cells, stimulation with DHF potentiates the MF synaptic transmission and increases the MF-EPSP - spike coupling. The latter exhibits a dramatic increase when picrotoxin is bath perfused after DHF, indicating that local interneurones restrain the excitability mediated by activation of TrkB. Therefore, we propose that release of BDNF on area CA3 reshapes the output of this hippocampal region by simultaneous activation of TrkB on GABAergic interneurones and pyramidal cells.
Collapse
Affiliation(s)
- Ernesto Griego
- Departamento de Farmacobiología, Cinvestav Sur, México City, México
| | | | | | - Germán Barrionuevo
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, United States
| | - Rafael Gutiérrez
- Departamento de Farmacobiología, Cinvestav Sur, México City, México
| | - Emilio J Galván
- Departamento de Farmacobiología, Cinvestav Sur, México City, México.
| |
Collapse
|
11
|
Marcantoni A, Calorio C, Hidisoglu E, Chiantia G, Carbone E. Cav1.2 channelopathies causing autism: new hallmarks on Timothy syndrome. Pflugers Arch 2020; 472:775-789. [PMID: 32621084 DOI: 10.1007/s00424-020-02430-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 02/07/2023]
Abstract
Cav1.2 L-type calcium channels play key roles in long-term synaptic plasticity, sensory transduction, muscle contraction, and hormone release. De novo mutations in the gene encoding Cav1.2 (CACNA1C) causes two forms of Timothy syndrome (TS1, TS2), characterized by a multisystem disorder inclusive of cardiac arrhythmias, long QT, autism, and adrenal gland dysfunction. In both TS1 and TS2, the missense mutation G406R is on the alternatively spliced exon 8 and 8A coding for the IS6-helix of Cav1.2 and is responsible for the penetrant form of autism in most TS individuals. The mutation causes specific gain-of-function changes to Cav1.2 channel gating: a "leftward shift" of voltage-dependent activation, reduced voltage-dependent inactivation, and a "leftward shift" of steady-state inactivation. How this occurs and how Cav1.2 gating changes alter neuronal firing and synaptic plasticity is still largely unexplained. Trying to better understanding the molecular basis of Cav1.2 gating dysfunctions leading to autism, here, we will present and discuss the properties of recently reported typical and atypical TS phenotypes and the effective gating changes exhibited by missense mutations associated with long QTs without extracardiac symptoms, unrelated to TS. We will also discuss new emerging views achieved from using iPSCs-derived neurons and the newly available autistic TS2-neo mouse model, both appearing promising for understanding neuronal mistuning in autistic TS patients. We will also analyze and describe recent proposals of molecular pathways that might explain mistuned Ca2+-mediated and Ca2+-independent excitation-transcription signals to the nucleus. Briefly, we will also discuss possible pharmacological approaches to treat autism associated with L-type channelopathies.
Collapse
Affiliation(s)
- Andrea Marcantoni
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, N.I.S. Centre, Corso Raffaello 30, 10125, Torino, Italy
| | - Chiara Calorio
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, N.I.S. Centre, Corso Raffaello 30, 10125, Torino, Italy
| | - Enis Hidisoglu
- Department of Biophysics, Faculty of Medicine, Akdeniz University, Antalya, Turkey
| | - Giuseppe Chiantia
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, N.I.S. Centre, Corso Raffaello 30, 10125, Torino, Italy
| | - Emilio Carbone
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, N.I.S. Centre, Corso Raffaello 30, 10125, Torino, Italy.
| |
Collapse
|
12
|
Gu F, Parada I, Yang T, Longo FM, Prince DA. Partial Activation of TrkB Receptors Corrects Interneuronal Calcium Channel Dysfunction and Reduces Epileptogenic Activity in Neocortex following Injury. Cereb Cortex 2020; 30:5180-5189. [PMID: 32488246 PMCID: PMC7391412 DOI: 10.1093/cercor/bhz254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 09/12/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
Decreased GABAergic inhibition due to dysfunction of inhibitory interneurons plays an important role in post-traumatic epileptogenesis. Reduced N-current Ca2+ channel function in GABAergic terminals contributes to interneuronal abnormalities and neural circuit hyperexcitability in the partial neocortical isolation (undercut, UC) model of post-traumatic epileptogenesis. Because brain-derived neurotrophic factor (BDNF) supports the development and maintenance of interneurons, we hypothesized that the activation of BDNF tropomyosin kinase B (TrkB) receptors by a small molecule, TrkB partial agonist, PTX BD4-3 (BD), would correct N channel abnormalities and enhance inhibitory synaptic transmission in UC cortex. Immunocytochemistry (ICC) and western blots were used to quantify N- and P/Q-type channels. We recorded evoked (e)IPSCs and responses to N and P/Q channel blockers to determine the effects of BD on channel function. Field potential recordings were used to determine the effects of BD on circuit hyperexcitability. Chronic BD treatment 1) upregulated N and P/Q channel immunoreactivity in GABAergic terminals; 2) increased the effects of N or P/Q channel blockade on evoked inhibitory postsynaptic currents (eIPSCs); 3) increased GABA release probability and the frequency of sIPSCs; and 4) reduced the incidence of epileptiform discharges in UC cortex. The results suggest that chronic TrkB activation is a promising approach for rescuing injury-induced calcium channel abnormalities in inhibitory terminals, thereby improving interneuronal function and suppressing circuit hyperexcitability.
Collapse
Affiliation(s)
- Feng Gu
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Isabel Parada
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Tao Yang
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Frank M Longo
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - David A Prince
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| |
Collapse
|
13
|
Marcantoni A, Cerullo MS, Buxeda P, Tomagra G, Giustetto M, Chiantia G, Carabelli V, Carbone E. Amyloid Beta42 oligomers up-regulate the excitatory synapses by potentiating presynaptic release while impairing postsynaptic NMDA receptors. J Physiol 2020; 598:2183-2197. [PMID: 32246769 DOI: 10.1113/jp279345] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/26/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS NMDA receptors (NMDARs) are key molecules for controlling neuronal plasticity, learning and memory processes. Their function is impaired during Alzheimer's disease (AD) but the exact consequence on synaptic function is not yet fully identified. An important hallmark of AD onset is represented by the neuronal accumulation of Amyloid Beta42 oligomers (Abeta42) that we have recently shown to be responsible for the increased intracellular Ca2+ concentration through ryanodine receptors (RyRs). Here we characterized the effects of Abeta42 on NMDA synapses showing specific pre- and post-synaptic functional changes that lead to a potentiation of basal and synchronous NMDA synaptic transmission. These overall effects can be abolished by decreasing Ca2+ release from RyRs with specific inhibitors that we propose as new pharmacological tools for AD treatment. ABSTRACT We have recently shown that Amyloid Beta42 oligomers (Abeta42) cause calcium dysregulation in hippocampal neurons by stimulating Ca2+ release from ryanodine receptors (RyRs) and inhibiting Ca2+ entry through NMDA receptors (NMDARs). Here, we found that Abeta42 decrease the average NMDA-activated inward current and that Ca2+ entry through NMDARs is accompanied by Ca2+ release from the stores. The overall amount of intraellular Ca2+ concentration([Ca2+ ]i ) increase during NMDA application is 50% associated with RyR opening and 50% with NMDARs activation. Addition of Abeta42 does not change this proportion. We estimated the number of NMDARs expressed in hippocampal neurons and their unitary current. We found that Abeta42 decrease the number of NMDARs without altering their unitary current. Paradoxically, the oligomer increases the size of electrically evoked eEPSCs induced by NMDARs activation. We found that this is the consequence of the increased release probability (p) of glutamate and the number of release sites (N) of NMDA synapses, while the quantal size (q) is significantly decreased as expected from the decreased number of NMDARs. An increased number of release sites induced by Abeta42 is also supported by the increased size of the ready releasable pool (RRPsyn) and by the enhanced percentage of paired pulse depression (PPD). Interestingly, the RyRs inhibitor dantrolene prevents the increase of PPD induced by Abeta42 oligomers. In conclusion, Abeta42 up-regulates NMDA synaptic responses with a mechanism involving RyRs that occurs during the early stages of Alzheimer's disease (AD) onset. This suggests that new selective modulators of RyRs may be useful for designing effective therapies to treat AD patients.
Collapse
Affiliation(s)
| | | | - Pol Buxeda
- Department of Drug Science and Technology, Torino University, Italy
| | - Giulia Tomagra
- Department of Drug Science and Technology, Torino University, Italy
| | - Maurizio Giustetto
- Department of Neurosciences / National Institute of Neuroscience, Torino University, Italy.,National Institute of Neuroscience-Italy, Turin, Italy
| | | | | | - Emilio Carbone
- Department of Drug Science and Technology, Torino University, Italy
| |
Collapse
|
14
|
Russo I, Gavello D, Menna E, Vandael D, Veglia C, Morello N, Corradini I, Focchi E, Alfieri A, Angelini C, Bianchi FT, Morellato A, Marcantoni A, Sassoè-Pognetto M, Ottaviani MM, Yekhlef L, Giustetto M, Taverna S, Carabelli V, Matteoli M, Carbone E, Turco E, Defilippi P. p140Cap Regulates GABAergic Synaptogenesis and Development of Hippocampal Inhibitory Circuits. Cereb Cortex 2020; 29:91-105. [PMID: 29161354 DOI: 10.1093/cercor/bhx306] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/23/2017] [Indexed: 01/19/2023] Open
Abstract
The neuronal scaffold protein p140Cap was investigated during hippocampal network formation. p140Cap is present in presynaptic GABAergic terminals and its genetic depletion results in a marked alteration of inhibitory synaptic activity. p140Cap-/- cultured neurons display higher frequency of miniature inhibitory postsynaptic currents (mIPSCs) with no changes of their mean amplitude. Consistent with a potential presynaptic alteration of basal GABA release, p140Cap-/- neurons exhibit a larger synaptic vesicle readily releasable pool, without any variation of single GABAA receptor unitary currents and number of postsynaptic channels. Furthermore, p140Cap-/- neurons show a premature and enhanced network synchronization and appear more susceptible to 4-aminopyridine-induced seizures in vitro and to kainate-induced seizures in vivo. The hippocampus of p140Cap-/- mice showed a significant increase in the number of both inhibitory synapses and of parvalbumin- and somatostatin-expressing interneurons. Specific deletion of p140Cap in forebrain interneurons resulted in increased susceptibility to in vitro epileptic events and increased inhibitory synaptogenesis, comparable to those observed in p140Cap-/- mice. Altogether, our data demonstrate that p140Cap finely tunes inhibitory synaptogenesis and GABAergic neurotransmission, thus regulating the establishment and maintenance of the proper hippocampal excitatory/inhibitory balance.
Collapse
Affiliation(s)
- Isabella Russo
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Daniela Gavello
- Department of Drug Science, University of Torino, Torino, Italy.,NIS Centre of Excellence, Torino, Italy
| | - Elisabetta Menna
- Institute of Neuroscience, CNR, Milano, Italy.,Istituto Clinico Humanitas, IRCCS, Rozzano, Italy
| | - David Vandael
- Department of Drug Science, University of Torino, Torino, Italy.,NIS Centre of Excellence, Torino, Italy
| | - Carola Veglia
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Noemi Morello
- Department of Neuroscience, University of Torino, Torino, Italy
| | - Irene Corradini
- Institute of Neuroscience, CNR, Milano, Italy.,Istituto Clinico Humanitas, IRCCS, Rozzano, Italy
| | | | - Annalisa Alfieri
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Costanza Angelini
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Federico Tommaso Bianchi
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Orbassano, Italy
| | - Alessandro Morellato
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Andrea Marcantoni
- Department of Drug Science, University of Torino, Torino, Italy.,NIS Centre of Excellence, Torino, Italy
| | - Marco Sassoè-Pognetto
- Department of Neuroscience, University of Torino, Torino, Italy.,National Institute of Neuroscience-Italy, Torino, Italy
| | | | - Latefa Yekhlef
- Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
| | - Maurizio Giustetto
- Department of Neuroscience, University of Torino, Torino, Italy.,National Institute of Neuroscience-Italy, Torino, Italy
| | - Stefano Taverna
- Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
| | - Valentina Carabelli
- Department of Drug Science, University of Torino, Torino, Italy.,NIS Centre of Excellence, Torino, Italy
| | - Michela Matteoli
- Institute of Neuroscience, CNR, Milano, Italy.,Istituto Clinico Humanitas, IRCCS, Rozzano, Italy
| | - Emilio Carbone
- Department of Drug Science, University of Torino, Torino, Italy.,NIS Centre of Excellence, Torino, Italy
| | - Emilia Turco
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Paola Defilippi
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| |
Collapse
|
15
|
Hameed MQ, Hsieh TH, Morales-Quezada L, Lee HHC, Damar U, MacMullin PC, Hensch TK, Rotenberg A. Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model. Cereb Cortex 2019; 29:4506-4518. [PMID: 30590449 PMCID: PMC7150617 DOI: 10.1093/cercor/bhy328] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022] Open
Abstract
Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a β-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.
Collapse
Affiliation(s)
- Mustafa Q Hameed
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tsung-Hsun Hsieh
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Physical Therapy & Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Leon Morales-Quezada
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Henry H C Lee
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ugur Damar
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Paul C MacMullin
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Takao K Hensch
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Molecular & Cellular Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexander Rotenberg
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
16
|
Gaidin SG, Turovskaya MV, Gavrish MS, Babaev AA, Mal'tseva VN, Blinova EV, Turovsky EA. The selective BDNF overexpression in neurons protects neuroglial networks against OGD and glutamate-induced excitotoxicity. Int J Neurosci 2019; 130:363-383. [PMID: 31694441 DOI: 10.1080/00207454.2019.1691205] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Objective: Cerebral ischemia is accompanied by damage and death of a significant number of neurons due to glutamate excitotoxicity with subsequent a global increase of cytosolic Ca2+ concentration ([Ca2+]i). This study aimed to investigate the neuroprotective action of BDNF overexpression in hippocampal neurons against injury under ischemia-like conditions (oxygen and glucose deprivation) and glutamate-induced excitotoxicity (GluTox).Methods: The overexpression of BDNF was reached by the transduction of cell cultures with the adeno-associated (AAV)-Syn-BDNF-EGFP virus construct. Neuroprotective effects were mediated by Ca2+-dependent BDNF release followed by activation of the neuroprotective signaling cascades and changes of the gene expression. Thus, BDNF overexpression modulates Ca2+ homeostasis in cells, preventing Ca2+ overload and initiation of apoptotic and necrotic processes.Results:Antiapoptotic effect of BDNF overexpression is mediated via activation of phosphoinositide-3-kinase (PI3K) pathway and changing the expression of PI3K, HIF-1, Src and an anti-inflammatory cytokine IL-10. On the contrary, the decrease of expression of proapoptotic proteins such as Jun, Mapk8, caspase-3 and an inflammatory cytokine IL-1β was observed. These changes of expression were accompanied by the decrease of quantity of IL-1β receptors and the level of TNFα in cells in control, as well as 24 h after OGD. Besides, BDNF overexpression changes the expression of GABA(B) receptors. Also, the expression of NMDA and AMPA receptor subunits was altered towards a change in the conductivity of the receptors for Ca2+.Conclusion: Thus, our results demonstrate that neuronal BDNF overexpression reveals complex neuroprotective effects on the neurons and astrocytes under OGD and GluTox via inhibition of Ca2+ responses and regulation of gene expression.
Collapse
Affiliation(s)
- S G Gaidin
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Russian Academy of Sciences, Pushchino, Russia
| | - M V Turovskaya
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Russian Academy of Sciences, Pushchino, Russia
| | - M S Gavrish
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - A A Babaev
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - V N Mal'tseva
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Russian Academy of Sciences, Pushchino, Russia
| | - E V Blinova
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia.,N. P. Ogarev Mordovia State University, Saransk, Russia
| | - E A Turovsky
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Russian Academy of Sciences, Pushchino, Russia
| |
Collapse
|
17
|
Gavello D, Calorio C, Franchino C, Cesano F, Carabelli V, Carbone E, Marcantoni A. Early Alterations of Hippocampal Neuronal Firing Induced by Abeta42. Cereb Cortex 2019; 28:433-446. [PMID: 27999123 DOI: 10.1093/cercor/bhw377] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Indexed: 12/11/2022] Open
Abstract
We studied the effect of Amyloid β 1-42 oligomers (Abeta42) on Ca2+ dependent excitability profile of hippocampal neurons. Abeta42 is one of the Amyloid beta peptides produced by the proteolytic processing of the amyloid precursor protein and participates in the initiating event triggering the progressive dismantling of synapses and neuronal circuits. Our experiments on cultured hippocampal network reveal that Abeta42 increases intracellular Ca2+ concentration by 46% and inhibits firing discharge by 19%. More precisely, Abeta42 differently regulates ryanodine (RyRs), NMDA receptors (NMDARs), and voltage gated calcium channels (VGCCs) by increasing Ca2+ release through RyRs and inhibiting Ca2+ influx through NMDARs and VGCCs. The overall increased intracellular Ca2+ concentration causes stimulation of K+ current carried by big conductance Ca2+ activated potassium (BK) channels and hippocampal network firing inhibition. We conclude that Abeta42 alters neuronal function by means of at least 4 main targets: RyRs, NMDARs, VGCCs, and BK channels. The development of selective modulators of these channels may in turn be useful for developing effective therapies that could enhance the quality of life of AD patients during the early onset of the pathology.
Collapse
Affiliation(s)
- Daniela Gavello
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Chiara Calorio
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Claudio Franchino
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Federico Cesano
- Department of Chemistry Via Pietro Giuria 7, Torino University, 10125 Torino, Italy
| | - Valentina Carabelli
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Emilio Carbone
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Andrea Marcantoni
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| |
Collapse
|
18
|
Chong PN, Sangu M, Huat TJ, Reza F, Begum T, Yusoff AAM, Jaafar H, Abdullah JM. Trkb-IP3 Pathway Mediating Neuroprotection in Rat Hippocampal Neuronal Cell Culture Following Induction of Kainic Acid. Malays J Med Sci 2018; 25:28-45. [PMID: 30914877 PMCID: PMC6422567 DOI: 10.21315/mjms2018.25.6.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 10/17/2018] [Indexed: 12/18/2022] Open
Abstract
Background Following brain injury, development of hippocampal sclerosis often led to the temporal lobe epilepsy which is sometimes resistant to common anti-epileptic drugs. Cellular and molecular changes underlying epileptogenesis in animal models were studied, however, the underlying mechanisms of kainic acid (KA) mediated neuronal damage in rat hippocampal neuron cell culture alone has not been elucidated yet. Methods Embryonic day 18 (E-18) rat hippocampus neurons were cultured with poly-L-lysine coated glass coverslips. Following optimisation, KA (0.5 μM), a chemoconvulsant agent, was administered at three different time-points (30, 60 and 90 min) to induce seizure in rat hippocampal neuronal cell culture. We examined cell viability, neurite outgrowth density and immunoreactivity of the hippocampus neuron culture by measuring brain derived neurotrophic factor (BDNF), γ-amino butyric acid A (GABAA) subunit α-1 (GABRA1), tyrosine receptor kinase B (TrkB), and inositol trisphosphate receptor (IP3R/IP3) levels. Results The results revealed significantly decreased and increased immunoreactivity changes in TrkB (a BDNF receptor) and IP3R, respectively, at 60 min time point. Conclusion The current findings suggest that TrkB and IP3 could have a neuroprotective role which could be a potential pharmacological target for anti-epilepsy drugs.
Collapse
Affiliation(s)
- Pei Nei Chong
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Muthuraju Sangu
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Tee Jong Huat
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Faruque Reza
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Tahamina Begum
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Abdul Aziz Mohamed Yusoff
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Hasnan Jaafar
- Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Jafri Malin Abdullah
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.,Centre for Neuroscience Services and Research, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| |
Collapse
|
19
|
Neuronal excitability and spontaneous synaptic transmission in the entorhinal cortex of BDNF heterozygous mice. Neurosci Lett 2018; 690:69-75. [PMID: 30316983 DOI: 10.1016/j.neulet.2018.10.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/21/2018] [Accepted: 10/10/2018] [Indexed: 02/04/2023]
Abstract
Brain Derived Neurotropic Factor (BDNF) is a neutrophic factor that is required for the normal neuronal development and function. BDNF is involved in regulation of synapses as well as neuronal excitability. Entorhinal Cortex (EC) is a key brain area involved in many physiological and pathological processes. In this study we investigated the effects of chronically reduced BDNF levels on layer 3 pyramidal neurons of EC. We aimed to assess the effects of reduced levels of BDNF on firing properties, spontaneous synaptic currents and excitation/inhibition balance from acute brain slices. Patch clamp recordings were obtained from pyramidal neurons of Entorhinal Cortex Layer 3. Findings of BDNF heterozygous (BDNF (+/-)) mice compared to their wild-type littermates at the age of 23-28 days. Action potential threshold was shifted (p = 0,002) to depolarized potentials and spike frequency was smaller in response to somatic current injection steps in BDNF (+/-) mice. Spontaneous synaptic currents were also affected. sEPSC amplitude (p = 0,009), sIPSC frequency (p = 0,001) and sIPSC amplitudes (p = 0,023) were reduced in BDNF (+/-). Decay times of sIPSCs were longer in BDNF (+/-) (p = 0,014). Calculated balance of excitatory/inhibitory balance was shifted in the favor of excitation in BDNF (+/-) mice (p = 0,01). These findings suggest that reductions in concentrations of BDNF results in altered status of excitability and excitation/inhibition imbalance. However, these differences observed in BDNF (+/-) seem to have opposing effects on neuronal activity.
Collapse
|
20
|
Tamura H, Shiosaka S, Morikawa S. Trophic modulation of gamma oscillations: The key role of processing protease for Neuregulin-1 and BDNF precursors. Neurochem Int 2018; 119:2-10. [DOI: 10.1016/j.neuint.2017.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/11/2017] [Accepted: 12/08/2017] [Indexed: 12/26/2022]
|
21
|
BDNF Val66Met polymorphism is associated with altered activity-dependent modulation of short-interval intracortical inhibition in bilateral M1. PLoS One 2018; 13:e0197505. [PMID: 29856758 PMCID: PMC5983496 DOI: 10.1371/journal.pone.0197505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 05/03/2018] [Indexed: 11/19/2022] Open
Abstract
The BDNF Val66Met polymorphism is associated with impaired short-term plasticity in the motor cortex, short-term motor learning, and intermanual transfer of a procedural motor skill. Here, we investigated the impact of the Val66Met polymorphism on the modulation of cortical excitability and interhemispheric inhibition through sensorimotor practice of simple dynamic skills with the right and left first dorsal interosseous (FDI) muscles. To that end, we compared motor evoked potentials (MEP) amplitudes and short-interval intracortical inhibition (SICI) in the bilateral representations of the FDI muscle in the primary motor cortex (M1), and interhemispheric inhibition (IHI) from the left to right M1, before and after right and left FDI muscle training in an alternated sequence. Val66Met participants did not differ from their Val66Val counterparts on motor performance at baseline and following motor training, or on measures of MEP amplitude and IHI. However, while the Val66Val group displayed significant SICI reduction in the bilateral M1 in response to motor training, SICI remained unchanged in the Val66Met group. Further, Val66Val group's SICI decrease in the left M1, which was also observed following unimanual training with the right hand in the Control Right group, was correlated with motor improvement with the left hand. The potential interaction between left and right M1 activity during bimanual training and the implications of altered activity-dependent cortical excitability on short-term motor learning in Val66Met carriers are discussed.
Collapse
|
22
|
New Insights into Microglia-Neuron Interactions: A Neuron's Perspective. Neuroscience 2018; 405:103-117. [PMID: 29753862 DOI: 10.1016/j.neuroscience.2018.04.046] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 01/16/2023]
Abstract
Microglia are the primary immune cells of the central nervous system. However, recent data indicate that microglia also contribute to diverse physiological and pathophysiological processes that extend beyond immune-related functions and there is a growing interest to understand the mechanisms through which microglia interact with other cells in the brain. In particular, the molecular processes that contribute to microglia-neuron communication in the healthy brain and their role in common brain diseases have been intensively studied during the last decade. In line with this, fate-mapping studies, genetic models and novel pharmacological approaches have revealed the origin of microglial progenitors, demonstrated the role of self-maintaining microglial populations during brain development or in adulthood, and identified the unexpectedly long lifespan of microglia that may profoundly change our view about senescence and age-related human diseases. Despite the exponentially increasing knowledge about microglia, the role of these cells in health and disease is still extremely controversial and the precise molecular targets for intervention are not well defined. This is in part due to the lack of microglia-specific manipulation approaches until very recently and to the high level of complexity of the interactions between microglia and other cells in the brain that occur at different temporal and spatial scales. In this review, we briefly summarize the known physiological roles of microglia-neuron interactions in brain homeostasis and attempt to outline some major directions and challenges of future microglia research.
Collapse
|
23
|
Guarina L, Calorio C, Gavello D, Moreva E, Traina P, Battiato A, Ditalia Tchernij S, Forneris J, Gai M, Picollo F, Olivero P, Genovese M, Carbone E, Marcantoni A, Carabelli V. Nanodiamonds-induced effects on neuronal firing of mouse hippocampal microcircuits. Sci Rep 2018; 8:2221. [PMID: 29396456 PMCID: PMC5797106 DOI: 10.1038/s41598-018-20528-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/11/2018] [Indexed: 01/31/2023] Open
Abstract
Fluorescent nanodiamonds (FND) are carbon-based nanomaterials that can efficiently incorporate optically active photoluminescent centers such as the nitrogen-vacancy complex, thus making them promising candidates as optical biolabels and drug-delivery agents. FNDs exhibit bright fluorescence without photobleaching combined with high uptake rate and low cytotoxicity. Focusing on FNDs interference with neuronal function, here we examined their effect on cultured hippocampal neurons, monitoring the whole network development as well as the electrophysiological properties of single neurons. We observed that FNDs drastically decreased the frequency of inhibitory (from 1.81 Hz to 0.86 Hz) and excitatory (from 1.61 to 0.68 Hz) miniature postsynaptic currents, and consistently reduced action potential (AP) firing frequency (by 36%), as measured by microelectrode arrays. On the contrary, bursts synchronization was preserved, as well as the amplitude of spontaneous inhibitory and excitatory events. Current-clamp recordings revealed that the ratio of neurons responding with AP trains of high-frequency (fast-spiking) versus neurons responding with trains of low-frequency (slow-spiking) was unaltered, suggesting that FNDs exerted a comparable action on neuronal subpopulations. At the single cell level, rapid onset of the somatic AP (“kink”) was drastically reduced in FND-treated neurons, suggesting a reduced contribution of axonal and dendritic components while preserving neuronal excitability.
Collapse
Affiliation(s)
- L Guarina
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - C Calorio
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - D Gavello
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - E Moreva
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy
| | - P Traina
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy
| | - A Battiato
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - S Ditalia Tchernij
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - J Forneris
- Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - M Gai
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy
| | - F Picollo
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - P Olivero
- Department of Physics and "NIS" inter-departmental centre, University of Torino, Via P. Giuria 1, 10125, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - M Genovese
- Istituto Nazionale Ricerca Metrologica, Strada delle Cacce 91, 10135, Torino, Italy.,Istituto Nazionale di Fisica Nucleare, sezione di Torino, Via P. Giuria 1, 10125, Torino, Italy
| | - E Carbone
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - A Marcantoni
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy
| | - V Carabelli
- Department of Drug Science and Technology, "NIS" inter-departmental centre, University of Torino, Corso Raffaello 30, 10125, Torino, Italy.
| |
Collapse
|
24
|
Gu F, Parada I, Yang T, Longo FM, Prince DA. Partial TrkB receptor activation suppresses cortical epileptogenesis through actions on parvalbumin interneurons. Neurobiol Dis 2018; 113:45-58. [PMID: 29408225 DOI: 10.1016/j.nbd.2018.01.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/21/2018] [Accepted: 01/24/2018] [Indexed: 01/17/2023] Open
Abstract
Post-traumatic epilepsy is one of the most common and difficult to treat forms of acquired epilepsy worldwide. Currently, there is no effective way to prevent post-traumatic epileptogenesis. It is known that abnormalities of interneurons, particularly parvalbumin-containing interneurons, play a critical role in epileptogenesis following traumatic brain injury. Thus, enhancing the function of existing parvalbumin interneurons might provide a logical therapeutic approach to prevention of post-traumatic epilepsy. The known positive effects of brain-derived neurotrophic factor on interneuronal growth and function through activation of its receptor tropomyosin receptor kinase B, and its decrease after traumatic brain injury, led us to hypothesize that enhancing trophic support might improve parvalbumin interneuronal function and decrease epileptogenesis. To test this hypothesis, we used the partial neocortical isolation ('undercut', UC) model of posttraumatic epileptogenesis in mature rats that were treated for 2 weeks, beginning on the day of injury, with LM22A-4, a newly designed partial agonist at the tropomyosin receptor kinase B. Effects of treatment were assessed with Western blots to measure pAKT/AKT; immunocytochemistry and whole cell patch clamp recordings to examine functional and structural properties of GABAergic interneurons; field potential recordings of epileptiform discharges in vitro; and video-EEG recordings of PTZ-induced seizures in vivo. Results showed that LM22A-4 treatment 1) increased pyramidal cell perisomatic immunoreactivity for VGAT, GAD65 and parvalbumin; 2) increased the density of close appositions of VGAT/gephyrin immunoreactive puncta (putative inhibitory synapses) on pyramidal cell somata; 3) increased the frequency of mIPSCs in pyramidal cells; and 4) decreased the incidence of spontaneous and evoked epileptiform discharges in vitro. 5) Treatment of rats with PTX BD4-3, another partial TrkB receptor agonist, reduced the incidence of bicuculline-induced ictal episodes in vitro and PTZ induced electrographic and behavioral ictal episodes in vivo. 6) Inactivation of TrkB receptors in undercut TrkBF616A mice with 1NMPP1 abolished both LM22A-4-induced effects on mIPSCs and on increased perisomatic VGAT-IR. Results indicate that chronic activation of the tropomyosin receptor kinase B by a partial agonist after cortical injury can enhance structural and functional measures of GABAergic inhibition and suppress posttraumatic epileptogenesis. Although the full agonist effects of brain-derived neurotrophic factor and tropomyosin receptor kinase B activation in epilepsy models have been controversial, the present results indicate that such trophic activation by a partial agonist may potentially serve as an effective therapeutic option for prophylactic treatment of posttraumatic epileptogenesis, and treatment of other neurological and psychiatric disorders whose pathogenesis involves impaired parvalbumin interneuronal function.
Collapse
Affiliation(s)
- Feng Gu
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Isabel Parada
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - David A Prince
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States.
| |
Collapse
|
25
|
Hansen MG, Ledri LN, Kirik D, Kokaia M, Ledri M. Preserved Function of Afferent Parvalbumin-Positive Perisomatic Inhibitory Synapses of Dentate Granule Cells in Rapidly Kindled Mice. Front Cell Neurosci 2018; 11:433. [PMID: 29375319 PMCID: PMC5767181 DOI: 10.3389/fncel.2017.00433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/22/2017] [Indexed: 11/13/2022] Open
Abstract
Parvalbumin- (PV-) containing basket cells constitute perisomatic GABAergic inhibitory interneurons innervating principal cells at perisomatic area, a strategic location that allows them to efficiently control the output and synchronize oscillatory activity at gamma frequency (30–90 Hz) oscillations. This oscillatory activity can convert into higher frequency epileptiform activity, and therefore could play an important role in the generation of seizures. However, the role of endogenous modulators of seizure activity, such as Neuropeptide Y (NPY), has not been fully explored in at PV input and output synapses. Here, using selective optogenetic activation of PV cells in the hippocampus, we show that seizures, induced by rapid kindling (RK) stimulations, enhance gamma-aminobutyric acid (GABA) release from PV cells onto dentate gyrus (DG) granule cells (GC). However, PV-GC synapses did not differ between controls and kindled animals in terms of GABA release probability, short-term plasticity and sensitivity to NPY. Kinetics of gamma-aminobutyric acid A (GABA-A) mediated currents in postsynaptic GC were also unaffected. When challenged by repetitive high-frequency optogenetic stimulations, PV synapses in kindled animals responded with enhanced GABA release onto GC. These results unveil a mechanism that might possibly contribute to the generation of abnormal synchrony and maintenance of epileptic seizures.
Collapse
Affiliation(s)
- Marita G Hansen
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Litsa N Ledri
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems (BRAINS) Unit, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Merab Kokaia
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Marco Ledri
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| |
Collapse
|
26
|
Valente P, Farisello P, Valtorta F, Baldelli P, Benfenati F. Impaired GABA B-mediated presynaptic inhibition increases excitatory strength and alters short-term plasticity in synapsin knockout mice. Oncotarget 2017; 8:90061-90076. [PMID: 29163811 PMCID: PMC5685732 DOI: 10.18632/oncotarget.21405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/03/2017] [Indexed: 11/25/2022] Open
Abstract
Synapsins are a family of synaptic vesicle phosphoproteins regulating synaptic transmission and plasticity. SYN1/2 genes are major epilepsy susceptibility genes in humans. Consistently, synapsin I/II/III triple knockout (TKO) mice are epileptic and exhibit severe impairments in phasic and tonic GABAergic inhibition that precede the appearance of the epileptic phenotype. These changes are associated with an increased strength of excitatory transmission that has never been mechanistically investigated. Here, we observed that an identical effect in excitatory transmission could be induced in wild-type (WT) Schaffer collateral-CA1 pyramidal cell synapses by blockade of GABAB receptors (GABABRs). The same treatment was virtually ineffective in TKO slices, suggesting that the increased strength of the excitatory transmission results from an impairment of GABAB presynaptic inhibition. Exogenous stimulation of GABABRs in excitatory autaptic neurons, where GABA spillover is negligible, demonstrated that GABABRs were effective in inhibiting excitatory transmission in both WT and TKO neurons. These results demonstrate that the decreased GABA release and spillover, previously observed in TKO hippocampal slices, removes the tonic brake of presynaptic GABABRs on glutamate transmission, making the excitation/inhibition imbalance stronger.
Collapse
Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy
| | - Pasqualina Farisello
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Flavia Valtorta
- S. Raffaele Scientific Institute and Vita-Salute University, 20132 Milano, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| |
Collapse
|
27
|
Ruan H, Gao J, Qi X, Tao Y, Guo X, Guo Z, Zheng L, Song Y, Liao Y, Shen W. Visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing Xenopus tectum in vivo. Dev Neurobiol 2017; 77:947-962. [PMID: 28033671 DOI: 10.1002/dneu.22480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/13/2016] [Accepted: 12/16/2016] [Indexed: 01/28/2023]
Abstract
Histone deacetylase 1 (HDAC1) is thought to play pivotal roles in neurogenesis and neurodegeneration. However, the role of HDAC1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. Here, we show that in the optic tectum of Xenopus laevis, HDAC1 knockdown dramatically decreased the frequency of AMPAR-mediated synaptic currents and increased the frequency of GABAAR-mediated currents, whereas HDAC1 overexpression significantly decreased the frequency of GABAAR-mediated synaptic currents. Both HDAC1 knockdown and overexpression adversely affected dendritic arbor growth and visual experience-dependent structural plasticity. Furthermore, HDAC1 knockdown decreased BDNF expression via a mechanism that involves acetylation of specific histone H4 residues at lysine K5. In particular, the deficits in dendritic growth and visually guided avoidance behavior in HDAC1-knockdown tadpoles could be rescued by acute tectal infusion of BDNF. These results establish a relationship between HDAC1 expression, histone H4 modification and BDNF signaling in the visual-experience dependent regulation of dendritic growth, structural plasticity and function in intact animals in vivo. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 947-962, 2017.
Collapse
Affiliation(s)
- Hangze Ruan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Xianjie Qi
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yi Tao
- Department of Neurosurgery, Nanjing Medical University Affiliated Jiangsu Cancer Hospital, Nanjing, Jiangsu, 210029, China
| | - Xia Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Zhaoyi Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Lijun Zheng
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yaling Song
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yuan Liao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| |
Collapse
|
28
|
Barnes AK, Koul-Tiwari R, Garner JM, Geist PA, Datta S. Activation of brain-derived neurotrophic factor-tropomyosin receptor kinase B signaling in the pedunculopontine tegmental nucleus: a novel mechanism for the homeostatic regulation of rapid eye movement sleep. J Neurochem 2017; 141:111-123. [PMID: 28027399 PMCID: PMC5364057 DOI: 10.1111/jnc.13938] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/09/2016] [Accepted: 12/09/2016] [Indexed: 02/04/2023]
Abstract
Rapid eye movement (REM) sleep dysregulation is a symptom of many neuropsychiatric disorders, yet the mechanisms of REM sleep homeostatic regulation are not fully understood. We have shown that, after REM sleep deprivation, the pedunculopontine tegmental nucleus (PPT) plays a critical role in the generation of recovery REM sleep. In this study, we used multidisciplinary techniques to show a causal relationship between brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling in the PPT and the development of REM sleep homeostatic drive. Rats were randomly assigned to conditions of unrestricted sleep or selective REM sleep deprivation (RSD) with PPT microinjections of vehicle control or a dose of a TrkB receptor inhibitor (2, 3, or 4 nmol K252a or 4 nmol ANA-12). On experimental days, rats received PPT microinjections and their sleep-wake physiological signals were recorded for 3 or 6 h, during which selective RSD was performed in the first 3 h. At the end of all 3 h recordings, rats were killed and the PPT was dissected out for BDNF quantification. Our results show that K252a and ANA-12 dose-dependently reduced the homeostatic responses to selective RSD. Specifically, TrkB receptor inhibition reduced REM sleep homeostatic drive and limited REM sleep rebound. There was also a dose-dependent suppression of PPT BDNF up-regulation, and regression analysis revealed a significant positive relationship between REM sleep homeostatic drive and the level of PPT BDNF expression. These data provide the first direct evidence that activation of BDNF-TrkB signaling in the PPT is a critical step for the development of REM sleep homeostatic drive.
Collapse
Affiliation(s)
- Abigail K Barnes
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Richa Koul-Tiwari
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Jennifer M Garner
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Phillip A Geist
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Subimal Datta
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA.,Program in Comparative and Experimental Medicine, The University of Tennessee, Knoxville, Tennessee, USA
| |
Collapse
|
29
|
BDNF-induced presynaptic facilitation of GABAergic transmission in the hippocampus of young adults is dependent of TrkB and adenosine A2A receptors. Purinergic Signal 2016; 12:283-94. [PMID: 26897393 DOI: 10.1007/s11302-016-9502-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/10/2016] [Indexed: 01/03/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) and adenosine are widely recognized as neuromodulators of glutamatergic transmission in the adult brain. Most BDNF actions upon excitatory plasticity phenomena are under control of adenosine A2A receptors (A2ARs). Concerning gamma-aminobutyric acid (GABA)-mediated transmission, the available information refers to the control of GABA transporters. We now focused on the influence of BDNF and the interplay with adenosine on phasic GABAergic transmission. To assess this, we evaluated evoked and spontaneous synaptic currents recorded from CA1 pyramidal cells in acute hippocampal slices from adult rat brains (6 to 10 weeks old). BDNF (10-100 ng/mL) increased miniature inhibitory postsynaptic current (mIPSC) frequency, but not amplitude, as well as increased the amplitude of inhibitory postsynaptic currents (IPSCs) evoked by afferent stimulation. The facilitatory action of BDNF upon GABAergic transmission was lost in the presence of a Trk inhibitor (K252a, 200 nM), but not upon p75(NTR) blockade (anti-p75(NTR) IgG, 50 μg/mL). Moreover, the facilitatory action of BDNF onto GABAergic transmission was also prevented upon A2AR antagonism (SCH 58261, 50 nM). We conclude that BDNF facilitates GABAergic signaling at the adult hippocampus via a presynaptic mechanism that depends on TrkB and adenosine A2AR activation.
Collapse
|
30
|
Prince D, Gu F, Parada I. Antiepileptogenic repair of excitatory and inhibitory synaptic connectivity after neocortical trauma. PROGRESS IN BRAIN RESEARCH 2016; 226:209-27. [DOI: 10.1016/bs.pbr.2016.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
31
|
Allio A, Calorio C, Franchino C, Gavello D, Carbone E, Marcantoni A. Bud extracts from Tilia tomentosa Moench inhibit hippocampal neuronal firing through GABAA and benzodiazepine receptors activation. JOURNAL OF ETHNOPHARMACOLOGY 2015; 172:288-296. [PMID: 26144285 DOI: 10.1016/j.jep.2015.06.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/10/2015] [Accepted: 06/14/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tilia tomentosa Moench bud extracts (TTBEs) is used in traditional medicine for centuries as sedative compound. Different plants belonging to the Tilia genus have shown their efficacy in the treatment of anxiety but still little is known about the mechanism of action of their bud extracts. AIM OF THE STUDY To evaluate the action of TTBEs as anxiolytic and sedative compound on in vitro hippocampal neurons. MATERIAL AND METHODS The anxiolytic effect of TTBEs was assayed by testing the effects of these compounds on GABAA receptor-activated chloride current of hippocampal neurons by means of the patch-clamp technique and microelectrode-arrays (MEAs). RESULTS TTBEs acutely administered on mouse hippocampal neurons, activated a chloride current comparable to that measured in the presence of GABA (100 µM). Bicuculline (100 µM) and picrotoxin (100 µM) blocked about 90% of this current, while the remaining 10% was blocked by adding the benzodiazepine (BDZ) antagonist flumazenil (30 µM). Flumazenil alone blocked nearly 60% of the TTBEs activated current, suggesting that TTBEs binds to both GABAA and BDZ receptor sites. Application of high-doses of TTBEs on spontaneous active hippocampal neurons grown for 3 weeks on MEAs blocked the synchronous activity of these neurons. The effects were mimicked by GABA and prevented by picrotoxin (100µM) and flumazenil (30 µM). At minimal doses, TTBEs reduced the frequency of synchronized bursts and increased the cross-correlation index of synchronized neuronal firing. CONCLUSIONS Our data suggest that TTBEs mimics GABA and BDZ agonists by targeting hippocampal GABAergic synapses and inhibiting network excitability by increasing the strength of inhibitory synaptic outputs. Our results contribute toward the validation of TTBEs as effective sedative and anxiolytic compound.
Collapse
Affiliation(s)
- Arianna Allio
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| | - Chiara Calorio
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| | - Claudio Franchino
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| | - Daniela Gavello
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| | - Emilio Carbone
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| | - Andrea Marcantoni
- Department of Drug Science and Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy.
| |
Collapse
|
32
|
ERV enhances spatial learning and prevents the development of infarcts, accompanied by upregulated BDNF in the cortex. Brain Res 2015; 1610:110-23. [PMID: 25842373 DOI: 10.1016/j.brainres.2015.03.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 03/19/2015] [Accepted: 03/24/2015] [Indexed: 01/18/2023]
Abstract
PURPOSES An anti-allergic and analgesic drug, "an extract derived from the inflamed cutaneous tissue of rabbits inoculated with vaccinia virus (ERV)", has been used in medical practice in Japan and some other countries. We examined the effect of ERV, prior to induction of ischemia, on the development of cerebral infarction, on learning and memory, or on brain-derived neurotrophic factor (BDNF) levels in C57BL/6J mice. METHODS Following oral administration of ERV (the same in humans: ×1) or vehicle, daily for three consecutive weeks, temporary focal ischemia was induced by the three vessel occlusion technique. In the other group of animals, after daily ERV (Low: ×1; Med: ×3, or High dose: ×9) or vehicle administration for three weeks, we performed a quantitative assessment of spatial learning or intracerebral BDNF levels. RESULTS The volumes of infarcted lesions, brain edema and the extent of the neurological deficits were significantly reduced in the ERV-treated group. ERV treatment also enhanced spatial learning, accompanied by upregulated BDNF in the cortex. CONCLUSIONS Daily oral intake of ERV, at a clinically relevant dose, protects the brain from ischemic stroke, and also enhances the learning function in normal mice. As millions of people are currently taking the drug safely, and have been for many years in some cases, there is a need to test the inhibitory actions of the drug on progressive dementia encountered in humans with recurrent ischemic attacks or Alzheimer's disease.
Collapse
|
33
|
Valente P, Orlando M, Raimondi A, Benfenati F, Baldelli P. Fine Tuning of Synaptic Plasticity and Filtering by GABA Released from Hippocampal Autaptic Granule Cells. Cereb Cortex 2015; 26:1149-67. [PMID: 25576534 DOI: 10.1093/cercor/bhu301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The functional consequence of γ-aminobutyric acid (GABA) release at mossy fiber terminals is still a debated topic. Here, we provide multiple evidence of GABA release in cultured autaptic hippocampal granule cells. In ∼50% of the excitatory autaptic neurons, GABA, VGAT, or GAD67 colocalized with vesicular glutamate transporter 1-positive puncta, where both GABAB and GABAA receptors (Rs) were present. Patch-clamp recordings showed a clear enhancement of autaptic excitatory postsynaptic currents in response to the application of the GABABR antagonist CGP58845 only in neurons positive to the selective granule cell marker Prox1, and expressing low levels of GAD67. Indeed, GCP non-responsive excitatory autaptic neurons were both Prox1- and GAD67-negative. Although the amount of released GABA was not sufficient to activate functional postsynaptic GABAARs, it effectively activated presynaptic GABABRs that maintain a tonic "brake" on the probability of release and on the size of the readily releasable pool and contributed to resting potential hyperpolarization possibly through extrasynaptic GABAAR activation. The autocrine inhibition exerted by GABABRs on glutamate release enhanced both paired-pulse facilitation and post-tetanic potentiation. Such GABABR-mediated changes in short-term plasticity confer to immature granule cells the capability to modulate their filtering properties in an activity-dependent fashion, with remarkable consequences on the dynamic behavior of neural circuits.
Collapse
Affiliation(s)
- Pierluigi Valente
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy Department of Experimental Medicine, Section of Physiology, University of Genova, Genova 16132, Italy
| | - Marta Orlando
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy
| | - Andrea Raimondi
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy
| | - Fabio Benfenati
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy Department of Experimental Medicine, Section of Physiology, University of Genova, Genova 16132, Italy
| | - Pietro Baldelli
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy Department of Experimental Medicine, Section of Physiology, University of Genova, Genova 16132, Italy
| |
Collapse
|
34
|
The activity-dependent transcription factor NPAS4 regulates domain-specific inhibition. Nature 2013; 503:121-5. [PMID: 24201284 DOI: 10.1038/nature12743] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 10/09/2013] [Indexed: 11/08/2022]
Abstract
A heterogeneous population of inhibitory neurons controls the flow of information through a neural circuit. Inhibitory synapses that form on pyramidal neuron dendrites modulate the summation of excitatory synaptic potentials and prevent the generation of dendritic calcium spikes. Precisely timed somatic inhibition limits both the number of action potentials and the time window during which firing can occur. The activity-dependent transcription factor NPAS4 regulates inhibitory synapse number and function in cell culture, but how this transcription factor affects the inhibitory inputs that form on distinct domains of a neuron in vivo was unclear. Here we show that in the mouse hippocampus behaviourally driven expression of NPAS4 coordinates the redistribution of inhibitory synapses made onto a CA1 pyramidal neuron, simultaneously increasing inhibitory synapse number on the cell body while decreasing the number of inhibitory synapses on the apical dendrites. This rearrangement of inhibition is mediated in part by the NPAS4 target gene brain derived neurotrophic factor (Bdnf), which specifically regulates somatic, and not dendritic, inhibition. These findings indicate that sensory stimuli, by inducing NPAS4 and its target genes, differentially control spatial features of neuronal inhibition in a way that restricts the output of the neuron while creating a dendritic environment that is permissive for plasticity.
Collapse
|
35
|
Ferrini F, De Koninck Y. Microglia control neuronal network excitability via BDNF signalling. Neural Plast 2013; 2013:429815. [PMID: 24089642 PMCID: PMC3780625 DOI: 10.1155/2013/429815] [Citation(s) in RCA: 229] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 07/28/2013] [Indexed: 12/27/2022] Open
Abstract
Microglia-neuron interactions play a crucial role in several neurological disorders characterized by altered neural network excitability, such as epilepsy and neuropathic pain. While a series of potential messengers have been postulated as substrates of the communication between microglia and neurons, including cytokines, purines, prostaglandins, and nitric oxide, the specific links between messengers, microglia, neuronal networks, and diseases have remained elusive. Brain-derived neurotrophic factor (BDNF) released by microglia emerges as an exception in this riddle. Here, we review the current knowledge on the role played by microglial BDNF in controlling neuronal excitability by causing disinhibition. The efforts made by different laboratories during the last decade have collectively provided a robust mechanistic paradigm which elucidates the mechanisms involved in the synthesis and release of BDNF from microglia, the downstream TrkB-mediated signals in neurons, and the biophysical mechanism by which disinhibition occurs, via the downregulation of the K⁺-Cl⁻ cotransporter KCC2, dysrupting Cl⁻ homeostasis, and hence the strength of GABA(A)- and glycine receptor-mediated inhibition. The resulting altered network activity appears to explain several features of the associated pathologies. Targeting the molecular players involved in this canonical signaling pathway may lead to novel therapeutic approach for ameliorating a wide array of neural dysfunctions.
Collapse
Affiliation(s)
- Francesco Ferrini
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095 Turin, Italy
| | - Yves De Koninck
- Institut Universitaire en Santé Mentale de Québec, Québec, QC, Canada G1J 2G3
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC, Canada G13 7P4
| |
Collapse
|
36
|
Ninan I. Synaptic regulation of affective behaviors; role of BDNF. Neuropharmacology 2013; 76 Pt C:684-95. [PMID: 23747574 DOI: 10.1016/j.neuropharm.2013.04.011] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 03/31/2013] [Accepted: 04/02/2013] [Indexed: 12/23/2022]
Abstract
Brain derived neurotrophic factor (BDNF), a neurotrophin essential for nervous system development and synaptic plasticity, has been found to have a significant influence on affective behaviors. The notion that an impairment in BDNF signaling might be involved in affective disorders is originated primarily from the opposing effects of antidepressants and stress on BDNF signaling. Antidepressants enhance BDNF signaling and synaptic plasticity. On the other hand, negative environmental factors such as severe stress suppress BDNF signaling, impair synaptic activity and increase susceptibility to affective disorders. Postmortem studies provided strong support for decreased BDNF signaling in depressive disorders. Remarkably, studies in humans with a single nucleotide polymorphism in the BDNF gene, the BDNF Val66Met which affects regulated release of BDNF, showed profound deficits in hippocampal and prefrontal cortical (PFC) plasticity and cognitive behaviors. BDNF regulates synaptic mechanisms responsible for various cognitive processes including attenuation of aversive memories, a key process in the regulation of affective behaviors. The unique role of BDNF in cognitive and affective behaviors suggests that cognitive deficits due to altered BDNF signaling might underlie affective disorders. Understanding how BDNF modulates synapses in neural circuits relevant to affective behaviors, particularly the medial prefrontal cortical (mPFC)-hippocampus-amygdala pathway, and its interaction with development, sex, and environmental risk factors might shed light on potential therapeutic targets for affective disorders. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.
Collapse
Affiliation(s)
- Ipe Ninan
- Department of Psychiatry, NYU School of Medicine, SKI 5-3, 540 1st Ave, NY 10016, United States.
| |
Collapse
|
37
|
Yang D, Nakajo Y, Iihara K, Kataoka H, Yanamoto H. Alogliptin, a dipeptidylpeptidase-4 inhibitor, for patients with diabetes mellitus type 2, induces tolerance to focal cerebral ischemia in non-diabetic, normal mice. Brain Res 2013; 1517:104-13. [PMID: 23602966 DOI: 10.1016/j.brainres.2013.04.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 12/15/2022]
Abstract
Effective interventions that provide obvious neuroprotection are currently fairly limited. Glucagon-like peptide-1 (GLP-1), an enhancer of insulin production with a trophic effect on β cells in the islets, has been found to be trophic for neuronal cells. Alogliptin benzoate (AGL), a selective inhibitor of dipeptidylpeptidase-4 (DPP-4) functioning as a long-acting agonist of GLP-1, is in clinical use worldwide for patients with diabetes mellitus type 2. To clarify whether administration of AGL, independent of the insulinotropic effect, protects the brain against focal ischemia, we investigated the effect of AGL on the development of cerebral infarction in non-diabetic normal mice. Male C57BL/6J mice were administered AGL (7.5, 15, or 30μg) once a day for three weeks by intragastric gavage. After the induction of temporary focal ischemia, volumes of infarcted lesions and neurological deficits were analyzed at 24h (acute phase) and seven days (chronic phase). In the acute phase, significant reductions were observed in the volumes of infarcted lesions (p=0.009), and in the severity of neurological deficits (p=0.004), in the group treated with 15μg of alogliptin benzoate, but not the 7.5 or 30μg-treated groups. This significant reduction in volumes of infarcted lesions persisted into the chronic phase. At the end of the AGL treatment; before the induction of ischemia, the levels of brain-derived neurotrophic factor (BDNF), a potent neuroprotectant in the brain, were elevated in the cortex (p=0.008), or in the whole forebrain (p=0.023). AGL could be used as a daily neuroprotectant or an enhancer of BDNF production aiming to attenuate cerebral injuries, for the growing number of people who have the risk of ischemic stroke.
Collapse
Affiliation(s)
- Dong Yang
- Laboratory of Neurology and Neurosurgery, National Cerebral and Cardiovascular Research Center, Suita 565-8565, Japan
| | | | | | | | | |
Collapse
|
38
|
Gonzalez JC, Lignani G, Maroto M, Baldelli P, Hernandez-Guijo JM. Presynaptic Muscarinic Receptors Reduce Synaptic Depression and Facilitate its Recovery at Hippocampal GABAergic Synapses. Cereb Cortex 2013; 24:1818-31. [DOI: 10.1093/cercor/bht032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
39
|
Maroto M, Fernández-Morales JC, Padín JF, González JC, Hernández-Guijo JM, Montell E, Vergés J, de Diego AMG, García AG. Chondroitin sulfate, a major component of the perineuronal net, elicits inward currents, cell depolarization, and calcium transients by acting on AMPA and kainate receptors of hippocampal neurons. J Neurochem 2013; 125:205-13. [PMID: 23350646 DOI: 10.1111/jnc.12159] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 10/08/2012] [Accepted: 01/15/2013] [Indexed: 12/19/2022]
Abstract
Chondroitin sulfate (CS) proteoglycans (CSPGs) are the most abundant PGs of the brain extracellular matrix (ECM). Free CS could be released during ECM degradation and exert physiological functions; thus, we aimed to investigate the effects of CS on voltage- and current-clamped rat embryo hippocampal neurons in primary cultures. We found that CS elicited a whole-cell Na(+)-dependent inward current (ICS) that produced drastic cell depolarization, and a cytosolic calcium transient ([Ca(2+)]c). Those effects were similar to those elicited by α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) and kainate, were completely blocked by NBQX and CNQX, were partially blocked by GYKI, and were unaffected by MK801 and D-APV. Furthermore, ICS and AMPA currents were similarly potentiated by cyclothiazide, a positive allosteric modulator of AMPA receptors. Because CSPGs have been attributed Ca(2) (+) -dependent roles, such as neural network development, axon pathfinding, plasticity and regeneration after CNS injury, CS action after ECM degradation could be contributing to the mediation of these effects through its interaction with AMPA and kainate receptors.
Collapse
Affiliation(s)
- Marcos Maroto
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - José-Carlos Fernández-Morales
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Juan Fernando Padín
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - José C González
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús M Hernández-Guijo
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Eulalia Montell
- Pre-Clinical R&D Area, Pharmascience Division, Bioibérica, Barcelona, Spain
| | - Josep Vergés
- Pre-Clinical R&D Area, Pharmascience Division, Bioibérica, Barcelona, Spain
| | - Antonio M G de Diego
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio G García
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa. Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
40
|
Laudes T, Meis S, Munsch T, Lessmann V. Impaired transmission at corticothalamic excitatory inputs and intrathalamic GABAergic synapses in the ventrobasal thalamus of heterozygous BDNF knockout mice. Neuroscience 2012; 222:215-27. [DOI: 10.1016/j.neuroscience.2012.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/27/2012] [Accepted: 07/02/2012] [Indexed: 01/08/2023]
|
41
|
Gavello D, Rojo-Ruiz J, Marcantoni A, Franchino C, Carbone E, Carabelli V. Leptin counteracts the hypoxia-induced inhibition of spontaneously firing hippocampal neurons: a microelectrode array study. PLoS One 2012; 7:e41530. [PMID: 22848520 PMCID: PMC3405131 DOI: 10.1371/journal.pone.0041530] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 06/26/2012] [Indexed: 01/24/2023] Open
Abstract
Besides regulating energy balance and reducing body-weight, the adipokine leptin has been recently shown to be neuroprotective and antiapoptotic by promoting neuronal survival after excitotoxic and oxidative insults. Here, we investigated the firing properties of mouse hippocampal neurons and the effects of leptin pretreatment on hypoxic damage (2 hours, 3% O(2)). Experiments were carried out by means of the microelectrode array (MEA) technology, monitoring hippocampal neurons activity from 11 to 18 days in vitro (DIV). Under normoxic conditions, hippocampal neurons were spontaneously firing, either with prevailing isolated and randomly distributed spikes (11 DIV), or with patterns characterized by synchronized bursts (18 DIV). Exposure to hypoxia severely impaired the spontaneous activity of hippocampal neurons, reducing their firing frequency by 54% and 69%, at 11 and 18 DIV respectively, and synchronized their firing activity. Pretreatment with 50 nM leptin reduced the firing frequency of normoxic neurons and contrasted the hypoxia-induced depressive action, either by limiting the firing frequency reduction (at both ages) or by increasing it to 126% (in younger neurons). In order to find out whether leptin exerts its effect by activating large conductance Ca(2+)-activated K(+) channels (BK), as shown on rat hippocampal neurons, we applied the BK channel blocker paxilline (1 µM). Our data show that paxilline reversed the effects of leptin, both on normoxic and hypoxic neurons, suggesting that the adipokine counteracts hypoxia through BK channels activation in mouse hippocampal neurons.
Collapse
Affiliation(s)
- Daniela Gavello
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
| | - Jonathan Rojo-Ruiz
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
| | - Andrea Marcantoni
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
| | - Claudio Franchino
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
| | - Emilio Carbone
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
| | - Valentina Carabelli
- Department of Drug Science and Technology, NIS Center, CNISM, University of Torino, Torino, Italy
- * E-mail:
| |
Collapse
|
42
|
Site-specific synapsin I phosphorylation participates in the expression of post-tetanic potentiation and its enhancement by BDNF. J Neurosci 2012; 32:5868-79. [PMID: 22539848 DOI: 10.1523/jneurosci.5275-11.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A large amount of experimental evidence has highlighted the rapid changes in synaptic efficacy induced by high-frequency stimulation and BDNF at central excitatory synapses. We clarified the quantal mechanisms and the involvement of Synapsin I (SynI) phosphorylation in the expression of post-tetanic potentiation (PTP) and in its modulation by BDNF in mouse glutamatergic autapses. We found that PTP is associated with an elevation in the probability of release and a concomitant increase in the size of the readily releasable pool (RRP). The latter component was virtually absent in SynI knock-out (KO) neurons, which indeed displayed impaired PTP. PTP was fully rescued by the expression of wild-type SynI, but not of its dephosphomimetic mutants in the phosphorylation sites for cAMP-dependent protein kinase and Ca²⁺/calmodulin-dependent protein kinases I/II. BDNF potently enhanced PTP through a further increase in the RRP size, which was missing in SynI KO neurons. In these neurons, the BDNF-induced PTP enhancement was rescued by the expression of wild-type SynI, but not of its dephosphomimetic mutant at the mitogen-dependent protein kinase sites. The results indicate that the increase in RRP size necessary for the full expression of PTP, and its sensitivity to BDNF, involve phosphorylation of SynI at distinct sites, thus implicating SynI as an essential downstream effector for the expression of PTP and for its enhancement by BDNF.
Collapse
|
43
|
Marconi E, Nieus T, Maccione A, Valente P, Simi A, Messa M, Dante S, Baldelli P, Berdondini L, Benfenati F. Emergent functional properties of neuronal networks with controlled topology. PLoS One 2012; 7:e34648. [PMID: 22493706 PMCID: PMC3321036 DOI: 10.1371/journal.pone.0034648] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Accepted: 03/05/2012] [Indexed: 01/30/2023] Open
Abstract
The interplay between anatomical connectivity and dynamics in neural networks plays a key role in the functional properties of the brain and in the associated connectivity changes induced by neural diseases. However, a detailed experimental investigation of this interplay at both cellular and population scales in the living brain is limited by accessibility. Alternatively, to investigate the basic operational principles with morphological, electrophysiological and computational methods, the activity emerging from large in vitro networks of primary neurons organized with imposed topologies can be studied. Here, we validated the use of a new bio-printing approach, which effectively maintains the topology of hippocampal cultures in vitro and investigated, by patch-clamp and MEA electrophysiology, the emerging functional properties of these grid-confined networks. In spite of differences in the organization of physical connectivity, our bio-patterned grid networks retained the key properties of synaptic transmission, short-term plasticity and overall network activity with respect to random networks. Interestingly, the imposed grid topology resulted in a reinforcement of functional connections along orthogonal directions, shorter connectivity links and a greatly increased spiking probability in response to focal stimulation. These results clearly demonstrate that reliable functional studies can nowadays be performed on large neuronal networks in the presence of sustained changes in the physical network connectivity.
Collapse
Affiliation(s)
- Emanuele Marconi
- Department of Neuroscience and Brain Technologies, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Farisello P, Boido D, Nieus T, Medrihan L, Cesca F, Valtorta F, Baldelli P, Benfenati F. Synaptic and extrasynaptic origin of the excitation/inhibition imbalance in the hippocampus of synapsin I/II/III knockout mice. Cereb Cortex 2012; 23:581-93. [PMID: 22368083 DOI: 10.1093/cercor/bhs041] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Synapsins (Syn I, Syn II, and Syn III) are a family of synaptic vesicle phosphoproteins regulating synaptic transmission and plasticity. SYN1/2 genes have been identified as major epilepsy susceptibility genes in humans and synapsin I/II/III triple knockout (TKO) mice are epileptic. However, excitatory and inhibitory synaptic transmission and short-term plasticity have never been analyzed in intact neuronal circuits of TKO mice. To clarify the generation and expression of the epileptic phenotype, we performed patch-clamp recordings in the CA1 region of acute hippocampal slices from 1-month-old presymptomatic and 6-month-old epileptic TKO mice and age-matched controls. We found a strong imbalance between basal glutamatergic and γ-aminobutyric acid (GABA)ergic transmission with increased evoked excitatory postsynaptic current and impaired evoked inhibitory postsynaptic current amplitude. This imbalance was accompanied by a parallel derangement of short-term plasticity paradigms, with enhanced facilitation of glutamatergic transmission in the presymptomatic phase and milder depression of inhibitory synapses in the symptomatic phase. Interestingly, a lower tonic GABA(A) current due to the impaired GABA release is responsible for the more depolarized resting potential found in TKO CA1 neurons, which makes them more susceptible to fire. All these changes preceded the appearance of epilepsy, indicating that the distinct changes in excitatory and inhibitory transmission due to the absence of Syns initiate the epileptogenic process.
Collapse
Affiliation(s)
- Pasqualina Farisello
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, 16163 Genova, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Kuzirian MS, Paradis S. Emerging themes in GABAergic synapse development. Prog Neurobiol 2011; 95:68-87. [PMID: 21798307 DOI: 10.1016/j.pneurobio.2011.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/30/2011] [Accepted: 07/03/2011] [Indexed: 12/25/2022]
Abstract
Glutamatergic synapse development has been rigorously investigated for the past two decades at both the molecular and cell biological level yet a comparable intensity of investigation into the cellular and molecular mechanisms of GABAergic synapse development has been lacking until relatively recently. This review will provide a detailed overview of the current understanding of GABAergic synapse development with a particular emphasis on assembly of synaptic components, molecular mechanisms of synaptic development, and a subset of human disorders which manifest when GABAergic synapse development is disrupted. An unexpected and emerging theme from these studies is that glutamatergic and GABAergic synapse development share a number of overlapping molecular and cell biological mechanisms that will be emphasized in this review.
Collapse
Affiliation(s)
- Marissa S Kuzirian
- Brandeis Univeristy, Department of Biology, National Center for Behavioral Genomics, Volen Center for Complex Systems, Waltham, MA 02453, USA
| | | |
Collapse
|
46
|
Jacobi S, Soriano J, Moses E. BDNF and NT-3 Increase Velocity of Activity Front Propagation in Unidimensional Hippocampal Cultures. J Neurophysiol 2010; 104:2932-9. [DOI: 10.1152/jn.00002.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neurotrophins are known to promote synapse development as well as to regulate the efficacy of mature synapses. We have previously reported that in two-dimensional rat hippocampal cultures, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 significantly increase the number of excitatory input connections. Here we measure the effect of these neurotrophic agents on propagating fronts that arise spontaneously in quasi-one-dimensional rat hippocampal cultures. We observe that chronic treatment with BDNF increased the velocity of the propagation front by about 30%. This change is attributed to an increase in the excitatory input connectivity. We analyze the experiment using the Feinerman–Golomb/Ermentrout–Jacobi/Moses–Osan model for the propagation of fronts in a one-dimensional neuronal network with synaptic delay and introduce the synaptic connection probability between adjacent neurons as a new parameter of the model. We conclude that BDNF increases the number of excitatory connections by favoring the probability to form connections between neurons, but without significantly modifying the range of the connections (connectivity footprint).
Collapse
Affiliation(s)
- Shimshon Jacobi
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel; and
| | - Jordi Soriano
- Departament Estructura i Constituents de la Matería, Facultat de Física, Universitat de Barcelona, Barcelona, Spain
| | - Elisha Moses
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel; and
| |
Collapse
|
47
|
González JC, Albiñana E, Baldelli P, García AG, Hernández-Guijo JM. Presynaptic muscarinic receptor subtypes involved in the enhancement of spontaneous GABAergic postsynaptic currents in hippocampal neurons. Eur J Neurosci 2010; 33:69-81. [PMID: 21091801 DOI: 10.1111/j.1460-9568.2010.07475.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigated the effects of muscarinic acetylcholine receptor (mAChR) activation on GABAergic synaptic transmission in rat hippocampal neurons. Current-clamp recordings revealed that methacholine produced membrane depolarization and action potential firing. Methacholine augmented the bicuculline-sensitive and GABA(A) -mediated frequency of spontaneous inhibitory postsynaptic currents (sIPSCs); the action of methacholine had a slow onset and longer duration. The increase in methacholine-evoked sIPSCs was completely inhibited by atropine and was insensitive to glutamatergic receptor blockers. Interestingly, methacholine action was not inhibited by intracellular perfusion with GDP-β-S, suggesting that muscarinic effects on membrane excitability and sIPSC frequency are mainly presynaptic. McN-A-343 and pirenzepine, selective agonist and antagonist of the m1 mAChR subtype, respectively, neither enhanced sIPSCs nor inhibited the methacholine effect. However, the m3-m5 mAChR antagonist 4-DAMP, and the m2-m4 mAChR antagonist himbacine inhibited the methacholine effect. U73122, an IP(3) production inhibitor, and 2APB, an IP(3) receptor blocker, drastically decreased the methacholine effect. Recording of miniature events revealed that besides the effect exerted by methacholine on membrane firing properties and sIPSC frequency, muscarinic receptors also enhanced the frequency of mIPSCs with no effect on their amplitude, possibly modulating the molecular machinery subserving vesicle docking and fusion and suggesting a tight colocalization at the active zone of the presynaptic terminals. These data strongly suggest that by activating presynaptic m2, m3, m4 and m5 mAChRs, methacholine can increase membrane excitability and enhance efficiency in the GABA release machinery, perhaps through a mechanism involving the release of calcium from the endoplasmic reticulum.
Collapse
Affiliation(s)
- J C González
- Instituto Teófilo Hernando, IIS Hospital Universitario de la Princesa, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | | | | | | | | |
Collapse
|
48
|
Brain-derived neurotrophic factor controls cannabinoid CB1 receptor function in the striatum. J Neurosci 2010; 30:8127-37. [PMID: 20554863 DOI: 10.1523/jneurosci.1683-10.2010] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The role of brain-derived neurotrophic factor (BDNF) in emotional processes suggests an interaction with the endocannabinoid system. Here, we addressed the functional interplay between BDNF and cannabinoid CB(1) receptors (CB(1)Rs) in the striatum, a brain area in which both BDNF and CB(1)s play a role in the emotional consequences of stress and of rewarding experiences. BDNF potently inhibited CB(1)R function in the striatum, through a mechanism mediated by altered cholesterol metabolism and membrane lipid raft function. The effect of BDNF was restricted to CB(1)Rs controlling GABA-mediated IPSCs (CB(1)R(GABA)), whereas CB(1)Rs modulating glutamate transmission and GABA(B) receptors were not affected. The action of BDNF on CB(1)R(GABA) function was tyrosine kinase dependent and was complete even after receptor sensitization with cocaine or environmental manipulations activating the dopamine (DA)-dependent reward system. In mice lacking one copy of the BDNF gene (BDNF(+/-)), CB(1)R(GABA) responses were potentiated and were preserved from the action of haloperidol, a DA D(2) receptor (D(2)R) antagonist able to fully abolish CB(1)R(GABA) function in rewarded animals. Haloperidol also enhanced BDNF levels in the striatum, suggesting that this neurotrophin may act as a downstream effector of D(2)Rs in the modulation of cannabinoid signaling. Accordingly, 5 d cocaine exposure both reduced striatal BDNF levels and increased CB(1)R(GABA) activity, through a mechanism dependent on D(2)Rs. The present study identifies a novel mechanism of CB(1)R regulation mediated by BDNF and cholesterol metabolism and provides some evidence that DA D(2)R-dependent modulation of striatal CB(1)R activity is mediated by this neurotrophin.
Collapse
|
49
|
Normal hearing is required for the emergence of long-lasting inhibitory potentiation in cortex. J Neurosci 2010; 30:331-41. [PMID: 20053914 DOI: 10.1523/jneurosci.4554-09.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Long-term synaptic plasticity is a putative mechanism for learning in adults. However, there is little understanding of how synaptic plasticity mechanisms develop or whether their maturation depends on experience. Since inhibitory synapses are particularly malleable to sensory stimulation, long-lasting potentiation of inhibitory synapses was characterized in auditory thalamocortical slices. Intracortical high-frequency electrical stimulation led to a 67% increase in inhibitory synaptic currents. In the absence of stimulation, inhibitory potentiation was induced by a brief exposure to exogenous brain-derived neurotrophic factor (BDNF). BDNF exposure occluded any additional potentiation by high-frequency afferent stimulation, suggesting that BDNF signaling is sufficient to account for inhibitory potentiation. Moreover, inhibitory potentiation was reduced significantly by extracellular application of a BDNF scavenger or by intracellular blockade of BDNF receptor [tropomyosin-related kinase B (TrkB)] signaling. In contrast, glutamatergic or GABAergic antagonists did not prevent the induction of inhibitory potentiation. Since BDNF and TrkB expression are influenced strongly by activity, we predicted that inhibitory potentiation would be diminished by manipulations that decrease central auditory activity, such as hearing loss. Two forms of hearing loss were examined: conductive hearing loss in which the cochleae are not damaged or sensorineural hearing loss in which both cochleae are removed. Both forms of hearing loss were found to reduce significantly the magnitude of inhibitory potentiation. These data indicate that early experience is necessary for the normal development of BDNF-mediated long-lasting inhibitory potentiation, which may be associated with perceptual deficits at later ages.
Collapse
|
50
|
Mizoguchi Y, Monji A, Kato T, Seki Y, Gotoh L, Horikawa H, Suzuki SO, Iwaki T, Yonaha M, Hashioka S, Kanba S. Brain-Derived Neurotrophic Factor Induces Sustained Elevation of Intracellular Ca2+ in Rodent Microglia. THE JOURNAL OF IMMUNOLOGY 2009; 183:7778-86. [DOI: 10.4049/jimmunol.0901326] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|