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Marinkovic K, Woodruff D, White DR, Caudle MM, Cronan T. Neural indices of multimodal sensory and autonomic hyperexcitability in fibromyalgia. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2023; 14:100140. [PMID: 38033709 PMCID: PMC10687342 DOI: 10.1016/j.ynpai.2023.100140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 12/02/2023]
Abstract
Fibromyalgia (FM) is characterized by chronic widespread musculoskeletal pain and psychological distress. Research suggests people with FM experience increased somatosensory sensitization which generalizes to other sensory modalities and may indicate neural hyperexcitability. However, the available evidence is limited, and studies including measures of neural responsivity across sensory domains and both central and peripheral aspects of the neuraxis are lacking. Thirty-nine participants (51.5 ± 13.6 years of age) with no history of neurological disorders, psychosis, visual, auditory, or learning deficits, were recruited for this study. People with FM (N = 19) and control participants (CNT, N = 20) did not differ on demographic variables and cognitive capacity. Participants completed a task that combined innocuous auditory stimuli with electrocutaneous stimulation (ECS), delivered at individually-selected levels that were uncomfortable but not painful. Event-related potentials (ERPs) and electrodermal activity were analyzed to examine the central and sympathetic indices of neural responsivity. FM participants reported greater sensitivity to ECS and auditory stimulation, as well as higher levels of depression, anxiety, ADHD, and an array of pain-related experiences than CNT. In response to ECS, the P50 deflection was greater in FM than CNT participants, reflecting early somatosensory hyperexcitability. The P50 amplitude was positively correlated with the FM profile factor obtained with a principal component analysis. The N100 to innocuous tones and sympathetic reactivity to ECS were greater in FM participants, except in the subgroup treated with gabapentinoids, which aligns with previous evidence of symptomatic improvement with GABA-mimetic medications. These results support the principal tenet of generalized neural hyperexcitability in FM and provide preliminary mechanistic insight into the impact of GABA-mimetic pharmacological therapy on ameliorating the neural excitation dominance.
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Affiliation(s)
- Ksenija Marinkovic
- Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
- San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 5500 Campanile Dr., San Diego, CA 92182, USA
- Department of Radiology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Denali Woodruff
- Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
| | - David R. White
- Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
| | - Morgan M. Caudle
- Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
- San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 5500 Campanile Dr., San Diego, CA 92182, USA
| | - Terry Cronan
- Department of Psychology, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
- San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 5500 Campanile Dr., San Diego, CA 92182, USA
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Nocon JC, Gritton HJ, James NM, Mount RA, Qu Z, Han X, Sen K. Parvalbumin neurons enhance temporal coding and reduce cortical noise in complex auditory scenes. Commun Biol 2023; 6:751. [PMID: 37468561 PMCID: PMC10356822 DOI: 10.1038/s42003-023-05126-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/10/2023] [Indexed: 07/21/2023] Open
Abstract
Cortical representations supporting many cognitive abilities emerge from underlying circuits comprised of several different cell types. However, cell type-specific contributions to rate and timing-based cortical coding are not well-understood. Here, we investigated the role of parvalbumin neurons in cortical complex scene analysis. Many complex scenes contain sensory stimuli which are highly dynamic in time and compete with stimuli at other spatial locations. Parvalbumin neurons play a fundamental role in balancing excitation and inhibition in cortex and sculpting cortical temporal dynamics; yet their specific role in encoding complex scenes via timing-based coding, and the robustness of temporal representations to spatial competition, has not been investigated. Here, we address these questions in auditory cortex of mice using a cocktail party-like paradigm, integrating electrophysiology, optogenetic manipulations, and a family of spike-distance metrics, to dissect parvalbumin neurons' contributions towards rate and timing-based coding. We find that suppressing parvalbumin neurons degrades cortical discrimination of dynamic sounds in a cocktail party-like setting via changes in rapid temporal modulations in rate and spike timing, and over a wide range of time-scales. Our findings suggest that parvalbumin neurons play a critical role in enhancing cortical temporal coding and reducing cortical noise, thereby improving representations of dynamic stimuli in complex scenes.
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Affiliation(s)
- Jian Carlo Nocon
- Neurophotonics Center, Boston University, Boston, 02215, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
- Hearing Research Center, Boston University, Boston, 02215, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, 02215, MA, USA
| | - Howard J Gritton
- Department of Comparative Biosciences, University of Illinois, Urbana, 61820, IL, USA
- Department of Bioengineering, University of Illinois, Urbana, 61820, IL, USA
| | - Nicholas M James
- Neurophotonics Center, Boston University, Boston, 02215, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
- Hearing Research Center, Boston University, Boston, 02215, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, 02215, MA, USA
| | - Rebecca A Mount
- Neurophotonics Center, Boston University, Boston, 02215, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
- Hearing Research Center, Boston University, Boston, 02215, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, 02215, MA, USA
| | - Zhili Qu
- Department of Comparative Biosciences, University of Illinois, Urbana, 61820, IL, USA
- Department of Bioengineering, University of Illinois, Urbana, 61820, IL, USA
| | - Xue Han
- Neurophotonics Center, Boston University, Boston, 02215, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
- Hearing Research Center, Boston University, Boston, 02215, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, 02215, MA, USA
| | - Kamal Sen
- Neurophotonics Center, Boston University, Boston, 02215, MA, USA.
- Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA.
- Hearing Research Center, Boston University, Boston, 02215, MA, USA.
- Department of Biomedical Engineering, Boston University, Boston, 02215, MA, USA.
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Scott KE, Mann RS, Schormans AL, Schmid S, Allman BL. Hyperexcitable and Immature-Like Neuronal Activity in the Auditory Cortex of Adult Rats Lacking the Language-Linked CNTNAP2 Gene. Cereb Cortex 2022; 32:4797-4817. [PMID: 35106542 PMCID: PMC9626820 DOI: 10.1093/cercor/bhab517] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/12/2022] Open
Abstract
The contactin-associated protein-like 2 gene, CNTNAP2, is a highly penetrant risk gene thought to play a role in the genetic etiology of language-related disorders, such as autism spectrum disorder and developmental language disorder. Despite its candidacy for influencing language development, few preclinical studies have examined the role of CNTNAP2 in auditory processing. Using in vivo and in vitro electrophysiological recordings in a rat model with translational validity, we report that a loss of the Cntnap2 gene function caused immature-like cortical evoked potentials, delayed multiunit response latencies to acoustic stimuli, impaired temporal processing, and led to a pattern of hyperexcitability in both multiunit and single cell recordings in adulthood. These collective results provide direct evidence that a constitutive loss of Cntnap2 gene function in rats can cause auditory processing impairments similar to those seen in language-related human disorders, indicating that its contribution in maintaining cortical neuron excitability may underlie the cortical activity alterations observed in Cntnap2−/− rats.
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Affiliation(s)
- Kaela E Scott
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Rajkamalpreet S Mann
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Ashley L Schormans
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Susanne Schmid
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Brian L Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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Kuntz A, Missonnier P, Prévot A, Favre G, Herrmann FR, Debatisse D, Merlo MCG, Gothuey I. Persistence of Neuronal Alterations in Alcohol-Dependent Patients at Conclusion of the Gold Standard Withdrawal Treatment: Evidence From ERPs. Front Psychiatry 2021; 12:666063. [PMID: 34526916 PMCID: PMC8435667 DOI: 10.3389/fpsyt.2021.666063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/23/2021] [Indexed: 11/24/2022] Open
Abstract
Background: One of the main challenges for clinicians is to ensure that alcohol withdrawal treatment is the most effective possible after discharge. To address this issue, we designed a pilot study to investigate the efficacy of the rehabilitation treatment on the main stages of information processing, using an electroencephalographic method. This topic is of main importance as relapse rates after alcohol withdrawal treatment remain very high, indicating that established treatment methods are not fully effective in all patients in the long run. Method: We examined in alcohol-dependent patients (ADP) the effects of the benzodiazepine-based standard detoxification program on event-related potential components at incoming (D0) and completion (D15) of the treatment, using tasks of increasing difficulty (with and without workload) during an auditory oddball target paradigm. Untreated non-alcohol-dependent-volunteers were used as matching controls. Results: At D0, ADP displayed significantly lower amplitude for all ERP components in both tasks, as compared to controls. At D15, this difference disappeared for the amplitude of the N1 component during the workload-free task, as well as the amplitude of the P3b for both tasks. Meanwhile, the amplitude of the N2 remained lower in both tasks for ADP. At D0, latencies of N2 and P3b in both task conditions were longer in ADP, as compared to controls, whilst the latency of N1 was unchanged. At D15, the N2 latency remained longer for the workload condition only, whereas the P3b latency remained longer for the workload-free task only. Conclusion: The present pilot results provide evidence for a persistence of impaired parameters of ERP components, especially the N2 component. This suggests that neural networks related to attention processing remain dysfunctional. Longitudinal long-term follow-up of these patients is mandatory for further assessment of a link between ERP alterations and a later risk of relapse.
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Affiliation(s)
- André Kuntz
- Mental Health Network Fribourg (RFSM), Sector of Psychiatry and Psychotherapy for Adults, Marsens, Switzerland
| | - Pascal Missonnier
- Mental Health Network Fribourg (RFSM), Sector of Psychiatry and Psychotherapy for Adults, Marsens, Switzerland.,Laboratory for Psychiatric Neuroscience and Psychotherapy, Department of Neuroscience, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Anne Prévot
- School of Health Sciences (HEdS-FR), HES-SO University of Applied Sciences and Arts Western Switzerland, Fribourg, Switzerland
| | - Grégoire Favre
- Mental Health Network Fribourg (RFSM), Sector of Psychiatry and Psychotherapy for Adults, Marsens, Switzerland.,Laboratory for Psychiatric Neuroscience and Psychotherapy, Department of Neuroscience, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - François R Herrmann
- Division of Geriatrics, Department of Rehabilitation and Geriatrics, Geneva University Hospitals and University of Geneva, Thônex, Switzerland
| | - Damien Debatisse
- HELIOS Privatkliniken GmbH - Wuppertal-Universität/Barmen, Wuppertal, Germany.,Department of Neurosurgery, Universität Kliniken der Stadt Köln gGmbH, Krankenhaus Merheim, Cologne, Germany
| | - Marco C G Merlo
- Laboratory for Psychiatric Neuroscience and Psychotherapy, Department of Neuroscience, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Isabelle Gothuey
- Mental Health Network Fribourg (RFSM), Sector of Psychiatry and Psychotherapy for Adults, Marsens, Switzerland
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Hayes SH, Schormans AL, Sigel G, Beh K, Herrmann B, Allman BL. Uncovering the contribution of enhanced central gain and altered cortical oscillations to tinnitus generation. Prog Neurobiol 2020; 196:101893. [PMID: 32783988 DOI: 10.1016/j.pneurobio.2020.101893] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/20/2020] [Accepted: 08/02/2020] [Indexed: 12/22/2022]
Abstract
Various theories and their associated mechanisms have been proposed as the neural basis of phantom sound perception (tinnitus), including central gain enhancement and altered cortical oscillations. However, it remains unknown whether these cortical changes directly cause tinnitus, or simply coexist with the phantom percept. Using chronically-implanted electrodes and drug delivery cannulae in rats, we examined whether enhanced central gain and cortical oscillations are consistent across different tinnitus induction methods (noise exposure; salicylate), and if directly-inducing enhanced central gain or altered cortical oscillations via pharmacologic manipulation of inhibition along the auditory pathway would cause behavioral evidence of tinnitus. We show that, while there appeared to be no clear link between tinnitus and the presence of enhanced sound-evoked cortical activity or altered spontaneous cortical oscillations, pharmacologic impairment of GABAergic neurotransmission in the auditory cortex was sufficient to cause tinnitus; collective findings which further advance our understanding of the neural basis of tinnitus.
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Affiliation(s)
- Sarah H Hayes
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada.
| | - Ashley L Schormans
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Gregory Sigel
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Krystal Beh
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Björn Herrmann
- Department of Psychology, Brain and Mind Institute, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Brian L Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
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6
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Liu X, Zhou L, Ding F, Wang Y, Yan J. Local field potentials are local events in the mouse auditory cortex. Eur J Neurosci 2015; 42:2289-97. [PMID: 26112462 PMCID: PMC5014213 DOI: 10.1111/ejn.13003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 06/05/2015] [Accepted: 06/18/2015] [Indexed: 11/30/2022]
Abstract
Local field potentials (LFPs) and spikes (SPKs) sampled at the thalamocortical recipient layers represent the inputs from the thalamus and outputs to other layers. Previous studies have shown that SPK‐constructed receptive fields (RFSPK) of cortical neurons are much smaller than LFP‐constructed RFs (RFLFP). The difference in cortical RFLFP and RFSPK is therefore a plausible indication of local networking. The presence of a boarder RFLFP appears due to contamination, to some degree, from remote sites. Our studies of the mouse primary auditory cortex show that the best frequencies and minimum thresholds of RFSPK and RFLFP were similar. We also observed that the RFLFP area was only slightly larger than the RFSPK area, a very different finding from previous reports. The bandwidth of RFLFP was slightly broader than that of RFSPK at all levels. These data do not support the explanation that bioelectrical signals from distant sites impact on cortical LFP through volume conduction. That the cortical LFP represents a local event is further supported by comparisons of RFSPK and RFLFP after cortical inhibition by muscimol and cortical disinhibition by bicuculine. We conclude that the difference between RFSPK (output of cortical neurons) and RFLFP (input of cortical neurons) results from intracortical processing, including cortical lateral inhibition and excitation.
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Affiliation(s)
- Xiuping Liu
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Linran Zhou
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Fangchao Ding
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Yehan Wang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Jun Yan
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
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7
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Tziridis K, Ahlf S, Jeschke M, Happel MFK, Ohl FW, Schulze H. Noise Trauma Induced Neural Plasticity Throughout the Auditory System of Mongolian Gerbils: Differences between Tinnitus Developing and Non-Developing Animals. Front Neurol 2015; 6:22. [PMID: 25713557 PMCID: PMC4322711 DOI: 10.3389/fneur.2015.00022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/27/2015] [Indexed: 12/29/2022] Open
Abstract
In this study, we describe differences between neural plasticity in auditory cortex (AC) of animals that developed subjective tinnitus (group T) after noise-induced hearing loss (NIHL) compared to those that did not [group non-tinnitus (NT)]. To this end, our analysis focuses on the input activity of cortical neurons based on the temporal and spectral analysis of local field potential (LFP) recordings and an in-depth analysis of auditory brainstem responses (ABR) in the same animals. In response to NIHL in NT animals we find a significant general reduction in overall cortical activity and spectral power as well as changes in all ABR wave amplitudes as a function of loudness. In contrast, T-animals show no significant change in overall cortical activity as assessed by root mean square analysis of LFP amplitudes, but a specific increase in LFP spectral power and in the amplitude of ABR wave V reflecting activity in the inferior colliculus (IC). Based on these results, we put forward a refined model of tinnitus prevention after NIHL that acts via a top-down global (i.e., frequency-unspecific) inhibition reducing overall neuronal activity in AC and IC, thereby counteracting NIHL-induced bottom-up frequency-specific neuroplasticity suggested in current models of tinnitus development.
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Affiliation(s)
- Konstantin Tziridis
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg , Erlangen , Germany
| | - Sönke Ahlf
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg , Erlangen , Germany
| | - Marcus Jeschke
- Leibniz Institute for Neurobiology , Magdeburg , Germany
| | - Max F K Happel
- Leibniz Institute for Neurobiology , Magdeburg , Germany ; Institute of Biology, Otto-von-Guericke-University , Magdeburg , Germany
| | - Frank W Ohl
- Leibniz Institute for Neurobiology , Magdeburg , Germany ; Institute of Biology, Otto-von-Guericke-University , Magdeburg , Germany ; Center for Behavioral Brain Sciences , Magdeburg , Germany
| | - Holger Schulze
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg , Erlangen , Germany
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Ahlf S, Tziridis K, Korn S, Strohmeyer I, Schulze H. Predisposition for and prevention of subjective tinnitus development. PLoS One 2012; 7:e44519. [PMID: 23056180 PMCID: PMC3462765 DOI: 10.1371/journal.pone.0044519] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/08/2012] [Indexed: 11/19/2022] Open
Abstract
Dysfunction of the inner ear as caused by presbyacusis, injuries or noise traumata may result in subjective tinnitus, but not everyone suffering from one of these diseases develops a tinnitus percept and vice versa. The reasons for these individual differences are still unclear and may explain why different treatments of the disease are beneficial for some patients but not for others. Here we for the first time compare behavioral and neurophysiological data from hearing impaired Mongolian gerbils with (T) and without (NT) a tinnitus percept that may elucidate why some specimen do develop subjective tinnitus after noise trauma while others do not. Although noise trauma induced a similar permanent hearing loss in all animals, tinnitus did develop only in about three quarters of these animals. NT animals showed higher overall cortical and auditory brainstem activity before noise trauma compared to T animals; that is, animals with low overall neuronal activity in the auditory system seem to be prone to develop tinnitus after noise trauma. Furthermore, T animals showed increased activity of cortical neurons representing the tinnitus frequencies after acoustic trauma, whereas NT animals exhibited an activity decrease at moderate sound intensities by that time. Spontaneous activity was generally increased in T but decreased in NT animals. Plastic changes of tonotopic organization were transient, only seen in T animals and vanished by the time the tinnitus percept became chronic. We propose a model for tinnitus prevention that points to a global inhibitory mechanism in auditory cortex that may prevent tinnitus genesis in animals with high overall activity in the auditory system, whereas this mechanism seems not potent enough for tinnitus prevention in animals with low overall activity.
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Affiliation(s)
- Sönke Ahlf
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Konstantin Tziridis
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Erlangen, Germany
- * E-mail:
| | - Sabine Korn
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Ilona Strohmeyer
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Holger Schulze
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Erlangen, Germany
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Felix RA, Kadner A, Berrebi AS. Effects of ketamine on response properties of neurons in the superior paraolivary nucleus of the mouse. Neuroscience 2011; 201:307-19. [PMID: 22123167 DOI: 10.1016/j.neuroscience.2011.11.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 11/09/2011] [Accepted: 11/10/2011] [Indexed: 11/19/2022]
Abstract
The superior paraolivary nucleus (SPON; alternative abbreviation: SPN for the same nucleus in certain species) is a prominent brainstem structure that provides strong inhibitory input to the auditory midbrain. Previous studies established that SPON neurons encode temporal sound features with high precision. These earlier characterizations of SPON responses were recorded under the influence of ketamine, a dissociative anesthetic agent and known antagonist of N-methyl-d-aspartate glutamate (NMDA) receptors. Because NMDA alters neural responses from the auditory brainstem, single unit extracellular recordings of SPON neurons were performed in the presence and absence of ketamine. In doing so, this study represents the first in vivo examination of the SPON of the mouse. Herein, independent data sets of SPON neurons are characterized that did or did not receive ketamine, as well as neurons that were recorded both prior to and following ketamine administration. In all conditions, SPON neurons exhibited contralaterally driven spikes triggered by the offset of pure tone stimuli. Ketamine lowered both evoked and spontaneous spiking, decreased the sharpness of frequency tuning, and increased auditory thresholds and first-spike latencies. In addition, ketamine limited the range of modulation frequencies to which neurons phase-locked to sinusoidally amplitude-modulated tones.
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Affiliation(s)
- R A Felix
- Department of Otolaryngology-Head and Neck Surgery, and the Sensory Neuroscience Research Center, PO Box 9303 Health Sciences Center, West Virginia University School of Medicine, Morgantown, WV 26506, USA
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10
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Moeller CK, Kurt S, Happel MFK, Schulze H. Long-range effects of GABAergic inhibition in gerbil primary auditory cortex. Eur J Neurosci 2009; 31:49-59. [PMID: 20092555 DOI: 10.1111/j.1460-9568.2009.07039.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Throughout the literature, the effects of iontophoretically applied neurotransmitter agonists or antagonists on the local activity of neurons are typically studied at the site of drug application. Recently, we have demonstrated long-range inhibitory interactions within the primary auditory cortex (AI) that are effective in complex acoustic situations. To further characterize this long-range functional connectivity, we here report the effects of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and the GABA(A) antagonist gabazine (SR 95531) on neuronal activity as a function of distance from the application site reaching beyond the diffusion radius of the applied drug. Neuronal responses to pure tone stimulation were simultaneously recorded at the application site and four additional sites, at distances between 300 and 1350 microm from the application site. We found that whereas application of GABA during best frequency (BF) stimulation in general led to a decrease, and gabazine to an increase, in neuronal activity at the application site, a considerable number of units at remote recording sites showed effects opposite to these local, drug-induced effects. These effects were seen both in spiking activity and in amplitudes of local field potentials. At all locations, the effects varied as a function of pure tone stimulation frequency, pointing to a Mexican-hat-like input function resulting from thalamic inputs to the BF region of the cortical neurons and intracortical interconnections projecting to off-BF regions of the neurons. These data demonstrate the existence of long-range, inhibitory interactions within the gerbil AI, realized either by long-range inhibitory projections or by long-range excitatory projections to local inhibitory interneurons.
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Affiliation(s)
- Christoph K Moeller
- Experimental Otolaryngology, University of Erlangen-Nuremberg, Waldstr. 1, 91054 Erlangen, Germany
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