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Deane KE, Klymentiev R, Heck J, Mark MD, Ohl FW, Heine M, Happel MFK. Inhibiting presynaptic calcium channel motility in the auditory cortex suppresses synchronized input processing. Front Cell Neurosci 2024; 18:1369047. [PMID: 38660672 PMCID: PMC11041022 DOI: 10.3389/fncel.2024.1369047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/18/2024] [Indexed: 04/26/2024] Open
Abstract
Introduction The emergent coherent population activity from thousands of stochastic neurons in the brain is believed to constitute a key neuronal mechanism for salient processing of external stimuli and its link to internal states like attention and perception. In the sensory cortex, functional cell assemblies are formed by recurrent excitation and inhibitory influences. The stochastic dynamics of each cell involved is largely orchestrated by presynaptic CAV2.1 voltage-gated calcium channels (VGCCs). Cav2.1 VGCCs initiate the release of neurotransmitters from the presynaptic compartment and are therefore able to add variability into synaptic transmission which can be partly explained by their mobile organization around docked vesicles. Methods To investigate the relevance of Cav2.1 channel surface motility for the input processing in the primary auditory cortex (A1) in vivo, we make use of a new optogenetic system which allows for acute, reversable cross-linking Cav2.1 VGCCs via a photo-cross-linkable cryptochrome mutant, CRY2olig. In order to map neuronal activity across all cortical layers of the A1, we performed laminar current-source density (CSD) recordings with varying auditory stimulus sets in transgenic mice with a citrine tag on the N-terminus of the VGCCs. Results Clustering VGCCs suppresses overall sensory-evoked population activity, particularly when stimuli lead to a highly synchronized distribution of synaptic inputs. Discussion Our findings reveal the importance of membrane dynamics of presynaptic calcium channels for sensory encoding by dynamically adjusting network activity across a wide range of synaptic input strength.
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Affiliation(s)
- Katrina E. Deane
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- University of California, Riverside, Riverside, CA, United States
| | - Ruslan Klymentiev
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute of Biology, Otto von Guericke University, Magdeburg, Germany
| | - Jennifer Heck
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Melanie D. Mark
- Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Frank W. Ohl
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute of Biology, Otto von Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Martin Heine
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Max F. K. Happel
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- MSB Medical School Berlin, Medical Faculty, Berlin, Germany
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2
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Happel MFK, Hechavarria JC, de Hoz L. Editorial: Cortical-Subcortical Loops in Sensory Processing. Front Neural Circuits 2022; 16:851612. [PMID: 35185480 PMCID: PMC8854134 DOI: 10.3389/fncir.2022.851612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Max F. K. Happel
- Medical Faculty, MSB Medical School Berlin, Berlin, Germany
- RG CortXplorer, Leibniz-Institute for Neurobiology, Magdeburg, Germany
- *Correspondence: Max F. K. Happel
| | - Julio C. Hechavarria
- Institute for Cell Biology and Neuroscience, Goethe University, Frankfurt am Main, Germany
| | - Livia de Hoz
- Neuroscience Research Center, Charité Medical University, Berlin, Germany
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3
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Saldeitis K, Jeschke M, Budinger E, Ohl FW, Happel MFK. Laser-Induced Apoptosis of Corticothalamic Neurons in Layer VI of Auditory Cortex Impact on Cortical Frequency Processing. Front Neural Circuits 2021; 15:659280. [PMID: 34322001 PMCID: PMC8311662 DOI: 10.3389/fncir.2021.659280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022] Open
Abstract
Corticofugal projections outnumber subcortical input projections by far. However, the specific role for signal processing of corticofugal feedback is still less well understood in comparisonto the feedforward projection. Here, we lesioned corticothalamic (CT) neurons in layers V and/or VI of the auditory cortex of Mongolian gerbils by laser-induced photolysis to investigate their contribution to cortical activation patterns. We have used laminar current-source density (CSD) recordings of tone-evoked responses and could show that, particularly, lesion of CT neurons in layer VI affected cortical frequency processing. Specifically, we found a decreased gain of best-frequency input in thalamocortical (TC)-recipient input layers that correlated with the relative lesion of layer VI neurons, but not layer V neurons. Using cortical silencing with the GABA a -agonist muscimol and layer-specific intracortical microstimulation (ICMS), we found that direct activation of infragranular layers recruited a local recurrent cortico-thalamo-cortical loop of synaptic input. This recurrent feedback was also only interrupted when lesioning layer VI neurons, but not cells in layer V. Our study thereby shows distinct roles of these two types of CT neurons suggesting a particular impact of CT feedback from layer VI to affect the local feedforward frequency processing in auditory cortex.
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Affiliation(s)
- Katja Saldeitis
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Auditory Neuroscience and Optogenetics Group, Cognitive Hearing in Primates Lab, German Primate Center, Göttingen, Germany.,Institute for Auditory Neuroscience, University Medical Center Goettingen, Göttingen, Germany
| | - Marcus Jeschke
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Auditory Neuroscience and Optogenetics Group, Cognitive Hearing in Primates Lab, German Primate Center, Göttingen, Germany.,Institute for Auditory Neuroscience, University Medical Center Goettingen, Göttingen, Germany
| | - Eike Budinger
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Frank W Ohl
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Institute for Auditory Neuroscience, University Medical Center Goettingen, Göttingen, Germany.,Institute of Biology (IBIO), University Magdeburg, Magdeburg, Germany
| | - Max F K Happel
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Medical School Berlin, Berlin, Germany
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4
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Lin X, Brunk MGK, Yuanxiang P, Curran AW, Zhang E, Stöber F, Goldschmidt J, Gundelfinger ED, Vollmer M, Happel MFK, Herrera-Molina R, Montag D. Neuroplastin expression is essential for hearing and hair cell PMCA expression. Brain Struct Funct 2021; 226:1533-1551. [PMID: 33844052 PMCID: PMC8096745 DOI: 10.1007/s00429-021-02269-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 03/27/2021] [Indexed: 12/25/2022]
Abstract
Hearing deficits impact on the communication with the external world and severely compromise perception of the surrounding. Deafness can be caused by particular mutations in the neuroplastin (Nptn) gene, which encodes a transmembrane recognition molecule of the immunoglobulin (Ig) superfamily and plasma membrane Calcium ATPase (PMCA) accessory subunit. This study investigates whether the complete absence of neuroplastin or the loss of neuroplastin in the adult after normal development lead to hearing impairment in mice analyzed by behavioral, electrophysiological, and in vivo imaging measurements. Auditory brainstem recordings from adult neuroplastin-deficient mice (Nptn-/-) show that these mice are deaf. With age, hair cells and spiral ganglion cells degenerate in Nptn-/- mice. Adult Nptn-/- mice fail to behaviorally respond to white noise and show reduced baseline blood flow in the auditory cortex (AC) as revealed by single-photon emission computed tomography (SPECT). In adult Nptn-/- mice, tone-evoked cortical activity was not detectable within the primary auditory field (A1) of the AC, although we observed non-persistent tone-like evoked activities in electrophysiological recordings of some young Nptn-/- mice. Conditional ablation of neuroplastin in Nptnlox/loxEmx1Cre mice reveals that behavioral responses to simple tones or white noise do not require neuroplastin expression by central glutamatergic neurons. Loss of neuroplastin from hair cells in adult NptnΔlox/loxPrCreERT mice after normal development is correlated with increased hearing thresholds and only high prepulse intensities result in effective prepulse inhibition (PPI) of the startle response. Furthermore, we show that neuroplastin is required for the expression of PMCA 2 in outer hair cells. This suggests that altered Ca2+ homeostasis underlies the observed hearing impairments and leads to hair cell degeneration. Our results underline the importance of neuroplastin for the development and the maintenance of the auditory system.
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Affiliation(s)
- Xiao Lin
- Neurogenetics Laboratory, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Michael G K Brunk
- Department System Physiology and Learning, AG CortXplorer, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Pingan Yuanxiang
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Andrew W Curran
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Enqi Zhang
- Institute of Medical Psychology, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Franziska Stöber
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Jürgen Goldschmidt
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Medical Faculty, Molecular Neuroscience, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Maike Vollmer
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Department of Otolaryngology-Head and Neck Surgery, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Max F K Happel
- Department System Physiology and Learning, AG CortXplorer, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Rodrigo Herrera-Molina
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Centro Integrativo de Biología Y Química Aplicada, Universidad Bernardo O'Higgins, 8307993, Santiago, Chile
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Dirk Montag
- Neurogenetics Laboratory, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.
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5
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Jeschke M, Happel MFK, Tziridis K, Krauss P, Schilling A, Schulze H, Ohl FW. Acute and Long-Term Circuit-Level Effects in the Auditory Cortex After Sound Trauma. Front Neurosci 2021; 14:598406. [PMID: 33469416 PMCID: PMC7813782 DOI: 10.3389/fnins.2020.598406] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/02/2020] [Indexed: 12/31/2022] Open
Abstract
Harmful environmental sounds are a prevailing source of chronic hearing impairments, including noise induced hearing loss, hyperacusis, or tinnitus. How these symptoms are related to pathophysiological damage to the sensory receptor epithelia and its effects along the auditory pathway, have been documented in numerous studies. An open question concerns the temporal evolution of maladaptive changes after damage and their manifestation in the balance of thalamocortical and corticocortical input to the auditory cortex (ACx). To address these issues, we investigated the loci of plastic reorganizations across the tonotopic axis of the auditory cortex of male Mongolian gerbils (Meriones unguiculatus) acutely after a sound trauma and after several weeks. We used a residual current-source density analysis to dissociate adaptations of intracolumnar input and horizontally relayed corticocortical input to synaptic populations across cortical layers in ACx. A pure tone-based sound trauma caused acute changes of subcortical inputs and corticocortical inputs at all tonotopic regions, particularly showing a broad reduction of tone-evoked inputs at tonotopic regions around the trauma frequency. At other cortical sites, the overall columnar activity acutely decreased, while relative contributions of lateral corticocortical inputs increased. After 4-6 weeks, cortical activity in response to the altered sensory inputs showed a general increase of local thalamocortical input reaching levels higher than before the trauma. Hence, our results suggest a detailed mechanism for overcompensation of altered frequency input in the auditory cortex that relies on a changing balance of thalamocortical and intracortical input and along the frequency gradient of the cortical tonotopic map.
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Affiliation(s)
- Marcus Jeschke
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
- Institute of Biology (IBIO), Otto-von-Guericke University Magdeburg (OVGU), Magdeburg, Germany
- Cognitive Hearing in Primates Group, Auditory Neuroscience and Optogenetics Laboratory, German Primate Center, Göttingen, Germany
- Institute for Auditory Neuroscience Göttingen, University Medical Center, Göttingen, Germany
| | - Max F. K. Happel
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
- Institute of Biology (IBIO), Otto-von-Guericke University Magdeburg (OVGU), Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Konstantin Tziridis
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Patrick Krauss
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Achim Schilling
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Holger Schulze
- Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Frank W. Ohl
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
- Institute of Biology (IBIO), Otto-von-Guericke University Magdeburg (OVGU), Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
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6
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Deane KE, Brunk MGK, Curran AW, Zempeltzi MM, Ma J, Lin X, Abela F, Aksit S, Deliano M, Ohl FW, Happel MFK. Ketamine anaesthesia induces gain enhancement via recurrent excitation in granular input layers of the auditory cortex. J Physiol 2020; 598:2741-2755. [PMID: 32329905 DOI: 10.1113/jp279705] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/16/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Ketamine is a common anaesthetic agent used in research and more recently as medication in treatment of depression. It has known effects on inhibition of interneurons and cortical stimulus-locked responses, but the underlying functional network mechanisms are still elusive. Analysing population activity across all layers within the auditory cortex, we found that doses of this anaesthetic induce a stronger activation and stimulus-locked response to pure-tone stimuli. This cortical response is driven by gain enhancement of thalamocortical input processing selectively within granular layers due to an increased recurrent excitation. Time-frequency analysis indicates a higher broadband magnitude response and prolonged phase coherence in granular layers, possibly pointing to disinhibition of this recurrent excitation. These results further the understanding of ketamine's functional mechanisms, which will improve the ability to interpret physiological studies moving from anaesthetized to awake paradigms and may lead to the development of better ketamine-based depression treatments with lower side effects. ABSTRACT Ketamine is commonly used as an anaesthetic agent and has more recently gained attention as an antidepressant. It has been linked to increased stimulus-locked excitability, inhibition of interneurons and modulation of intrinsic neuronal oscillations. However, the functional network mechanisms are still elusive. A better understanding of these anaesthetic network effects may improve upon previous interpretations of seminal studies conducted under anaesthesia and have widespread relevance for neuroscience with awake and anaesthetized subjects as well as in medicine. Here, we investigated the effects of anaesthetic doses of ketamine (15 mg kg-1 h-1 i.p.) on the network activity after pure-tone stimulation within the auditory cortex of male Mongolian gerbils (Meriones unguiculatus). We used laminar current source density (CSD) analysis and subsequent layer-specific continuous wavelet analysis to investigate spatiotemporal response dynamics on cortical columnar processing in awake and ketamine-anaesthetized animals. We found thalamocortical input processing within granular layers III/IV to be significantly increased under ketamine. This layer-dependent gain enhancement under ketamine was not due to changes in cross-trial phase coherence but was rather attributed to a broadband increase in magnitude reflecting an increase in recurrent excitation. A time-frequency analysis was indicative of a prolonged period of stimulus-induced excitation possibly due to a reduced coupling of excitation and inhibition in granular input circuits - in line with the common hypothesis of cortical disinhibition via suppression of GABAergic interneurons.
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Affiliation(s)
- Katrina E Deane
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany
| | | | - Andrew W Curran
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany.,Graduate School of Life Science, Julius Maximilians University, Würzburg, D-97074, Germany
| | | | - Jing Ma
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany
| | - Xiao Lin
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany
| | - Francesca Abela
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany.,University of Pisa, Pisa, I-56126, Italy
| | - Sümeyra Aksit
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany
| | | | - Frank W Ohl
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany.,Institute of Biology, Otto von Guericke University, Magdeburg, D-39120, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, 39106, Germany
| | - Max F K Happel
- Leibniz Institute for Neurobiology, Magdeburg, D-39118, Germany.,Institute of Biology, Otto von Guericke University, Magdeburg, D-39120, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, 39106, Germany
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7
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Mitlöhner J, Kaushik R, Niekisch H, Blondiaux A, Gee CE, Happel MFK, Gundelfinger E, Dityatev A, Frischknecht R, Seidenbecher C. Dopamine Receptor Activation Modulates the Integrity of the Perisynaptic Extracellular Matrix at Excitatory Synapses. Cells 2020; 9:cells9020260. [PMID: 31972963 PMCID: PMC7073179 DOI: 10.3390/cells9020260] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 01/08/2023] Open
Abstract
In the brain, Hebbian-type and homeostatic forms of plasticity are affected by neuromodulators like dopamine (DA). Modifications of the perisynaptic extracellular matrix (ECM), which control the functions and mobility of synaptic receptors as well as the diffusion of transmitters and neuromodulators in the extracellular space, are crucial for the manifestation of plasticity. Mechanistic links between synaptic activation and ECM modifications are largely unknown. Here, we report that neuromodulation via D1-type DA receptors can induce targeted ECM proteolysis specifically at excitatory synapses of rat cortical neurons via proteases ADAMTS-4 and -5. We showed that receptor activation induces increased proteolysis of brevican (BC) and aggrecan, two major constituents of the adult ECM both in vivo and in vitro. ADAMTS immunoreactivity was detected near synapses, and shRNA-mediated knockdown reduced BC cleavage. We have outlined a molecular scenario of how synaptic activity and neuromodulation are linked to ECM rearrangements via increased cAMP levels, NMDA receptor activation, and intracellular calcium signaling.
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Affiliation(s)
- Jessica Mitlöhner
- Leibniz Institute for Neurobiology (LIN), Department of Neurochemistry and Molecular Biology, 39118 Magdeburg, Germany; (J.M.); (A.B.); (E.G.)
| | - Rahul Kaushik
- German Center for Neurodegenerative Diseases (DZNE), Molecular Neuroplasticity Group, 39120 Magdeburg, Germany;
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
| | - Hartmut Niekisch
- Leibniz Institute for Neurobiology (LIN), Department of Systems Physiology of Learning, 39118 Magdeburg, Germany; (H.N.); (M.F.K.H.)
| | - Armand Blondiaux
- Leibniz Institute for Neurobiology (LIN), Department of Neurochemistry and Molecular Biology, 39118 Magdeburg, Germany; (J.M.); (A.B.); (E.G.)
| | - Christine E. Gee
- Center for Molecular Neurobiology Hamburg (ZMNH), Institute for Synaptic Physiology, 20251 Hamburg, Germany;
| | - Max F. K. Happel
- Leibniz Institute for Neurobiology (LIN), Department of Systems Physiology of Learning, 39118 Magdeburg, Germany; (H.N.); (M.F.K.H.)
| | - Eckart Gundelfinger
- Leibniz Institute for Neurobiology (LIN), Department of Neurochemistry and Molecular Biology, 39118 Magdeburg, Germany; (J.M.); (A.B.); (E.G.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
- Otto-von-Guericke University, Medical Faculty, 39120 Magdeburg, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), Molecular Neuroplasticity Group, 39120 Magdeburg, Germany;
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
- Otto-von-Guericke University, Medical Faculty, 39120 Magdeburg, Germany
- Correspondence: (A.D.); (R.F.); (C.S.); Tel.: +49-391 67-24526 (A.D.); +49-9131 85-28051 (R.F.); +49-391-6263-92401 (C.S.)
| | - Renato Frischknecht
- Leibniz Institute for Neurobiology (LIN), Department of Neurochemistry and Molecular Biology, 39118 Magdeburg, Germany; (J.M.); (A.B.); (E.G.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
- Correspondence: (A.D.); (R.F.); (C.S.); Tel.: +49-391 67-24526 (A.D.); +49-9131 85-28051 (R.F.); +49-391-6263-92401 (C.S.)
| | - Constanze Seidenbecher
- Leibniz Institute for Neurobiology (LIN), Department of Neurochemistry and Molecular Biology, 39118 Magdeburg, Germany; (J.M.); (A.B.); (E.G.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
- Otto-von-Guericke University, Medical Faculty, 39120 Magdeburg, Germany
- Correspondence: (A.D.); (R.F.); (C.S.); Tel.: +49-391 67-24526 (A.D.); +49-9131 85-28051 (R.F.); +49-391-6263-92401 (C.S.)
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8
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Brunk MGK, Deane KE, Kisse M, Deliano M, Vieweg S, Ohl FW, Lippert MT, Happel MFK. Optogenetic stimulation of the VTA modulates a frequency-specific gain of thalamocortical inputs in infragranular layers of the auditory cortex. Sci Rep 2019; 9:20385. [PMID: 31892726 PMCID: PMC6938496 DOI: 10.1038/s41598-019-56926-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/16/2019] [Indexed: 12/22/2022] Open
Abstract
Reward associations during auditory learning induce cortical plasticity in the primary auditory cortex. A prominent source of such influence is the ventral tegmental area (VTA), which conveys a dopaminergic teaching signal to the primary auditory cortex. Yet, it is unknown, how the VTA influences cortical frequency processing and spectral integration. Therefore, we investigated the temporal effects of direct optogenetic stimulation of the VTA onto spectral integration in the auditory cortex on a synaptic circuit level by current-source-density analysis in anesthetized Mongolian gerbils. While auditory lemniscal input predominantly terminates in the granular input layers III/IV, we found that VTA-mediated modulation of spectral processing is relayed by a different circuit, namely enhanced thalamic inputs to the infragranular layers Vb/VIa. Activation of this circuit yields a frequency-specific gain amplification of local sensory input and enhances corticocortical information transfer, especially in supragranular layers I/II. This effects persisted over more than 30 minutes after VTA stimulation. Altogether, we demonstrate that the VTA exhibits a long-lasting influence on sensory cortical processing via infragranular layers transcending the signaling of a mere reward-prediction error. We thereby demonstrate a cellular and circuit substrate for the influence of reinforcement-evaluating brain systems on sensory processing in the auditory cortex.
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Affiliation(s)
- Michael G K Brunk
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
| | - Katrina E Deane
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Martin Kisse
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Matthias Deliano
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Silvia Vieweg
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - Frank W Ohl
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
- Institute for Biology, Otto-von-Guericke-University, 39120, Magdeburg, Germany
| | - Michael T Lippert
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Max F K Happel
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
- Institute for Biology, Otto-von-Guericke-University, 39120, Magdeburg, Germany.
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Deliano M, Brunk MGK, El-Tabbal M, Zempeltzi MM, Happel MFK, Ohl FW. Dopaminergic neuromodulation of high gamma stimulus phase-locking in gerbil primary auditory cortex mediated by D1/D5-receptors. Eur J Neurosci 2018. [PMID: 29514417 DOI: 10.1111/ejn.13898] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cortical release of the neurotransmitter dopamine has been implied in adapting cortical processing with respect to various functions including coding of stimulus salience, expectancy, error prediction, behavioral relevance and learning. Dopamine agonists have been shown to modulate recurrent cortico-thalamic feedback, and should therefore also affect synchronization and amplitude of thalamo-cortical oscillations. In this study, we have used multitaper spectral and time-frequency analysis of stimulus-evoked and spontaneous current source density patterns in primary auditory cortex of Mongolian gerbils to characterize dopaminergic neuromodulation of the oscillatory structure of current sources and sinks. We systemically applied D1/D5-receptor agonist SKF-38393 followed by competitive D1/D5-receptor antagonist SCH-23390. Our results reveal an increase in stimulus phase-locking in the high gamma-band (88-97 Hz) by SKF-38393, specifically in layers III/IV at the best frequency, which occurred at 20 ms after tone onset, and was reversed by SCH-23390. However, changes in induced oscillatory power after SKF-38393 treatment occurred stimulus-independently in the background activity in different layers than phase-locking effects and were not reversed by SCH-23390. These effects might either reflect longer-lasting changes in neural background noise, non-specific changes due to ketamine anesthesia, or an interaction of both. Without concomitant stimulus-induced power increase, increased stimulus phase-locking in layers III/IV indicates enhanced phase-resetting of neural oscillations by the stimulus after D1/D5-receptor activation. The frequency characteristics, together with the demonstrated stimulus specificity and layer specificity, suggest that changes in phase-resetting originate from dopaminergic neuromodulation of thalamo-cortical interactions. Enhanced phase-resetting might be a key step in the recruitment of cortical activity modes interpreting sensory input.
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Affiliation(s)
- Matthias Deliano
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany
| | - Michael G K Brunk
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany
| | - Mohamed El-Tabbal
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany
| | - Maria M Zempeltzi
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany
| | - Max F K Happel
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany
| | - Frank W Ohl
- Department Systems Physiology of Learning (SPL), Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, Magdeburg, 39118, Germany.,Otto von Guericke University (OVGU), Magdeburg, Germany.,Center for Behavioral Brain Sciences (OVGU), Magdeburg, Germany
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10
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Happel MFK, Ohl FW. Compensating Level-Dependent Frequency Representation in Auditory Cortex by Synaptic Integration of Corticocortical Input. PLoS One 2017; 12:e0169461. [PMID: 28046062 PMCID: PMC5207691 DOI: 10.1371/journal.pone.0169461] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/16/2016] [Indexed: 11/20/2022] Open
Abstract
Robust perception of auditory objects over a large range of sound intensities is a fundamental feature of the auditory system. However, firing characteristics of single neurons across the entire auditory system, like the frequency tuning, can change significantly with stimulus intensity. Physiological correlates of level-constancy of auditory representations hence should be manifested on the level of larger neuronal assemblies or population patterns. In this study we have investigated how information of frequency and sound level is integrated on the circuit-level in the primary auditory cortex (AI) of the Mongolian gerbil. We used a combination of pharmacological silencing of corticocortically relayed activity and laminar current source density (CSD) analysis. Our data demonstrate that with increasing stimulus intensities progressively lower frequencies lead to the maximal impulse response within cortical input layers at a given cortical site inherited from thalamocortical synaptic inputs. We further identified a temporally precise intercolumnar synaptic convergence of early thalamocortical and horizontal corticocortical inputs. Later tone-evoked activity in upper layers showed a preservation of broad tonotopic tuning across sound levels without shifts towards lower frequencies. Synaptic integration within corticocortical circuits may hence contribute to a level-robust representation of auditory information on a neuronal population level in the auditory cortex.
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Affiliation(s)
- Max F. K. Happel
- Leibniz Institute for Neurobiology, D-39118, Magdeburg, Germany
- Institute of Biology, Otto-von-Guericke-University, D-39120 Magdeburg, Germany
- * E-mail: (MH); (FO)
| | - Frank W. Ohl
- Leibniz Institute for Neurobiology, D-39118, Magdeburg, Germany
- Institute of Biology, Otto-von-Guericke-University, D-39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- * E-mail: (MH); (FO)
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11
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Abstract
The harmonic structure of sounds is an important grouping cue in auditory scene analysis. The ability of ferrets to detect mistuned harmonics was measured using a go/no-go task paradigm. Psychometric functions plotting sensitivity as a function of degree of mistuning were used to evaluate behavioral performance using signal detection theory. The mean (± standard error of the mean) threshold for mistuning detection was 0.8 ± 0.1 Hz, with sensitivity indices and reaction times depending on the degree of mistuning. These data provide a basis for investigation of the neural basis for the perception of complex sounds in ferrets, an increasingly used animal model in auditory research.
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Affiliation(s)
- Natsumi Y Homma
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom , , ,
| | - Victoria M Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom , , ,
| | - Max F K Happel
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom , , ,
| | - Fernando R Nodal
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom , , ,
| | - Andrew J King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, United Kingdom , , ,
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12
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Happel MFK. Dopaminergic impact on local and global cortical circuit processing during learning. Behav Brain Res 2015; 299:32-41. [PMID: 26608540 DOI: 10.1016/j.bbr.2015.11.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/10/2015] [Accepted: 11/15/2015] [Indexed: 11/17/2022]
Abstract
We have learned to detect, predict and behaviorally respond to important changes in our environment on short and longer time scales. Therefore, brains of humans and higher animals build upon a perceptual and semantic salience stored in their memories mainly generated by associative reinforcement learning. Functionally, the brain needs to extract and amplify a small number of features of sensory input with behavioral relevance to a particular situation in order to guide behavior. In this review, I argue that dopamine action, particularly in sensory cortex, orchestrates layer-dependent local and long-range cortical circuits integrating sensory associated bottom-up and semantically relevant top-down information, respectively. Available evidence reveals that dopamine thereby controls both the selection of perceptually or semantically salient signals as well as feedback processing from higher-order areas in the brain. Sensory cortical dopamine thereby governs the integration of selected sensory information within a behavioral context. This review proposes that dopamine enfolds this function by temporally distinct actions on particular layer-dependent local and global cortical circuits underlying the integration of sensory, and non-sensory cognitive and behavioral variables.
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Affiliation(s)
- Max F K Happel
- Leibniz Institute for Neurobiology, D-39118 Magdeburg, Germany; Institute of Biology, Otto-von-Guericke-University, D-39120 Magdeburg, Germany.
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13
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Happel MFK, Deliano M, Ohl FW. Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning. J Vis Exp 2015:e53002. [PMID: 26556300 DOI: 10.3791/53002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Shuttle-box avoidance learning is a well-established method in behavioral neuroscience and experimental setups were traditionally custom-made; the necessary equipment is now available by several commercial companies. This protocol provides a detailed description of a two-way shuttle-box avoidance learning paradigm in rodents (here Mongolian gerbils; Meriones unguiculatus) in combination with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical electrophysiological in vivo recordings. The detailed protocol is applicable to study multiple aspects of learning behavior and perception in different rodent species. Site-specific ICMS of auditory cortical circuits as conditioned stimuli here is used as a tool to test the perceptual relevance of specific afferent, efferent and intracortical connections. Distinct activation patterns can be evoked by using different stimulation electrode arrays for local, layer-dependent ICMS or distant ICMS sites. Utilizing behavioral signal detection analysis it can be determined which stimulation strategy is most effective for eliciting a behaviorally detectable and salient signal. Further, parallel multichannel-recordings using different electrode designs (surface electrodes, depth electrodes, etc.) allow for investigating neuronal observables over the time course of such learning processes. It will be discussed how changes of the behavioral design can increase the cognitive complexity (e.g. detection, discrimination, reversal learning).
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Affiliation(s)
- Max F K Happel
- Leibniz Institute for Neurobiology, Magdeburg, Germany; Otto-von-Guericke University, Magdeburg, Germany;
| | | | - Frank W Ohl
- Leibniz Institute for Neurobiology, Magdeburg, Germany; Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Meyer AF, Diepenbrock JP, Happel MFK, Ohl FW, Anemüller J. Discriminative learning of receptive fields from responses to non-Gaussian stimulus ensembles. PLoS One 2014; 9:e93062. [PMID: 24699631 PMCID: PMC3974709 DOI: 10.1371/journal.pone.0093062] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/28/2014] [Indexed: 11/19/2022] Open
Abstract
Analysis of sensory neurons' processing characteristics requires simultaneous measurement of presented stimuli and concurrent spike responses. The functional transformation from high-dimensional stimulus space to the binary space of spike and non-spike responses is commonly described with linear-nonlinear models, whose linear filter component describes the neuron's receptive field. From a machine learning perspective, this corresponds to the binary classification problem of discriminating spike-eliciting from non-spike-eliciting stimulus examples. The classification-based receptive field (CbRF) estimation method proposed here adapts a linear large-margin classifier to optimally predict experimental stimulus-response data and subsequently interprets learned classifier weights as the neuron's receptive field filter. Computational learning theory provides a theoretical framework for learning from data and guarantees optimality in the sense that the risk of erroneously assigning a spike-eliciting stimulus example to the non-spike class (and vice versa) is minimized. Efficacy of the CbRF method is validated with simulations and for auditory spectro-temporal receptive field (STRF) estimation from experimental recordings in the auditory midbrain of Mongolian gerbils. Acoustic stimulation is performed with frequency-modulated tone complexes that mimic properties of natural stimuli, specifically non-Gaussian amplitude distribution and higher-order correlations. Results demonstrate that the proposed approach successfully identifies correct underlying STRFs, even in cases where second-order methods based on the spike-triggered average (STA) do not. Applied to small data samples, the method is shown to converge on smaller amounts of experimental recordings and with lower estimation variance than the generalized linear model and recent information theoretic methods. Thus, CbRF estimation may prove useful for investigation of neuronal processes in response to natural stimuli and in settings where rapid adaptation is induced by experimental design.
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Affiliation(s)
- Arne F. Meyer
- Department of Medical Physics and Acoustics and Cluster of Excellence ''Hearing4all'', University of Oldenburg, Oldenburg, Germany
- * E-mail:
| | - Jan-Philipp Diepenbrock
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Max F. K. Happel
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Department of Neuroprosthetics, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
| | - Frank W. Ohl
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Department of Neuroprosthetics, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
| | - Jörn Anemüller
- Department of Medical Physics and Acoustics and Cluster of Excellence ''Hearing4all'', University of Oldenburg, Oldenburg, Germany
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16
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Lison H, Happel MFK, Schneider F, Baldauf K, Kerbstat S, Seelbinder B, Schneeberg J, Zappe M, Goldschmidt J, Budinger E, Schröder UH, Ohl FW, Schilling S, Demuth HU, Scheich H, Reymann KG, Rönicke R. Disrupted cross-laminar cortical processing in β amyloid pathology precedes cell death. Neurobiol Dis 2013; 63:62-73. [PMID: 24291517 DOI: 10.1016/j.nbd.2013.11.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/04/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023] Open
Abstract
Disruption of neuronal networks in the Alzheimer-afflicted brain is increasingly recognized as a key correlate of cognitive and memory decline in Alzheimer patients. We hypothesized that functional synaptic disconnections within cortical columnar microcircuits by pathological β-amyloid accumulation, rather than cell death, initially causes the cognitive impairments. During development of cortical β-amyloidosis with still few plaques in the transgenic 5xFAD mouse model single cell resolution mapping of neuronal thallium uptake revealed that electrical activity of pyramidal cells breaks down throughout infragranular cortical layer V long before cell death occurs. Treatment of 5xFAD mice with the glutaminyl cyclase inhibitor, PQ 529, partially prevented the decline of pyramidal cell activity, indicating pyroglutamate-modified forms, potentially mixed oligomers of Aβ are contributing to neuronal impairment. Laminar investigation of cortical circuit dysfunction with current source density analysis identified an early loss of excitatory synaptic input in infragranular layers, linked to pathological recurrent activations in supragranular layers. This specific disruption of normal cross-laminar cortical processing coincided with a decline of contextual fear learning.
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Affiliation(s)
- H Lison
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - M F K Happel
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - F Schneider
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - K Baldauf
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - S Kerbstat
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - B Seelbinder
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - J Schneeberg
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - M Zappe
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - J Goldschmidt
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - E Budinger
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - U H Schröder
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - F W Ohl
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - S Schilling
- Probiodrug AG, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - H-U Demuth
- Probiodrug AG, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - H Scheich
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - K G Reymann
- Leibniz-Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany
| | - R Rönicke
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), c/o Universitätsklinikum Magdeburg, Leipziger Strasse 44/Haus 64, 39120 Magdeburg, Germany; Department of Clinical Chemistry and Pathobiochemistry, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
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17
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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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