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Hyperactive somatostatin interneurons contribute to excitotoxicity in neurodegenerative disorders. Nat Neurosci 2016; 19:557-559. [PMID: 26900927 PMCID: PMC4811704 DOI: 10.1038/nn.4257] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/27/2016] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are overlapping neurodegenerative disorders whose pathogenesis remains largely unknown. Here using TDP-43A315T mice, an ALS and FTD model with profound cortical pathology, we demonstrated that hyperactive somatostatin interneurons disinhibited layer 5 pyramidal neurons (L5-PN) and contributed to their excitotoxicity. Focal ablation of somatostatin interneurons efficiently restored normal excitability of L5-PN and alleviated neurodegeneration, suggesting a novel therapeutic target for ALS and FTD.
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102
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Castejon C, Barros-Zulaica N, Nuñez A. Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function. PLoS One 2016; 11:e0148169. [PMID: 26820514 PMCID: PMC4731153 DOI: 10.1371/journal.pone.0148169] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 01/13/2016] [Indexed: 11/19/2022] Open
Abstract
Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm) is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1) in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.
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Affiliation(s)
- Carlos Castejon
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Natali Barros-Zulaica
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Angel Nuñez
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- * E-mail:
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103
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Clark R, Blizzard C, Dickson T. Inhibitory dysfunction in amyotrophic lateral sclerosis: future therapeutic opportunities. Neurodegener Dis Manag 2015; 5:511-25. [DOI: 10.2217/nmt.15.49] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In amyotrophic lateral sclerosis, motor neuron hyperexcitability and inhibitory dysfunction is emerging as a potential causative link in the dysfunction and degeneration of the motoneuronal circuitry that characterizes the disease. Interneurons, as key regulators of excitability, may mediate much of this imbalance, yet we know little about the way in which inhibitory deficits perturb excitability. In this review, we explore inhibitory control of excitability and the potential contribution of altered inhibition to amyotrophic lateral sclerosis disease processes and vulnerabilities, identifying important windows of therapeutic opportunity and potential interventions, specifically targeting inhibitory control at key disease stages.
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Affiliation(s)
- Rosemary Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
| | - Catherine Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
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104
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Modes and nodes explain the mechanism of action of vortioxetine, a multimodal agent (MMA): blocking 5HT3 receptors enhances release of serotonin, norepinephrine, and acetylcholine. CNS Spectr 2015; 20:455-9. [PMID: 26122791 DOI: 10.1017/s1092852915000346] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Vortioxetine is an antidepressant with multiple pharmacologic modes of action at targets where serotonin neurons connect with other neurons. 5HT3 receptor antagonism is one of these actions, and this leads to increased release of norepinephrine (NE), acetylcholine (ACh), and serotonin (5HT) within various brain circuits.
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105
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Modes and nodes explain the mechanism of action of vortioxetine, a multimodal agent (MMA): modifying serotonin's downstream effects on glutamate and GABA (gamma amino butyric acid) release. CNS Spectr 2015; 20:331-6. [PMID: 26062900 DOI: 10.1017/s1092852915000334] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Vortioxetine is an antidepressant with multiple pharmacologic modes of action at targets where serotonin neurons connect with other neurons. These actions modify the release of both glutamate and GABA (gamma amino butyric acid) within various brain circuits.
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106
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Kubota Y, Kondo S, Nomura M, Hatada S, Yamaguchi N, Mohamed AA, Karube F, Lübke J, Kawaguchi Y. Functional effects of distinct innervation styles of pyramidal cells by fast spiking cortical interneurons. eLife 2015; 4. [PMID: 26142457 PMCID: PMC4518632 DOI: 10.7554/elife.07919] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/04/2015] [Indexed: 01/16/2023] Open
Abstract
Inhibitory interneurons target precise membrane regions on pyramidal cells, but differences in their functional effects on somata, dendrites and spines remain unclear. We analyzed inhibitory synaptic events induced by cortical, fast-spiking (FS) basket cells which innervate dendritic shafts and spines as well as pyramidal cell somata. Serial electron micrograph (EMg) reconstructions showed that somatic synapses were larger than dendritic contacts. Simulations with precise anatomical and physiological data reveal functional differences between different innervation styles. FS cell soma-targeting synapses initiate a strong, global inhibition, those on shafts inhibit more restricted dendritic zones, while synapses on spines may mediate a strictly local veto. Thus, FS cell synapses of different sizes and sites provide functionally diverse forms of pyramidal cell inhibition.
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Affiliation(s)
- Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Satoru Kondo
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Masaki Nomura
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Sayuri Hatada
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Noboru Yamaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Alsayed A Mohamed
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Fuyuki Karube
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Joachim Lübke
- Institute of Neuroscience and Medicine, Research Centre Jülich, Jülich, Germany
| | - Yasuo Kawaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
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107
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Nassar M, Simonnet J, Lofredi R, Cohen I, Savary E, Yanagawa Y, Miles R, Fricker D. Diversity and overlap of parvalbumin and somatostatin expressing interneurons in mouse presubiculum. Front Neural Circuits 2015; 9:20. [PMID: 26005406 PMCID: PMC4424818 DOI: 10.3389/fncir.2015.00020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/20/2015] [Indexed: 12/17/2022] Open
Abstract
The presubiculum, located between hippocampus and entorhinal cortex, plays a fundamental role in representing spatial information, notably head direction. Little is known about GABAergic interneurons of this region. Here, we used three transgenic mouse lines, Pvalb-Cre, Sst-Cre, and X98, to examine distinct interneurons labeled with tdTomato or green fluorescent protein. The distribution of interneurons in presubicular lamina for each animal line was compared to that in the GAD67-GFP knock-in animal line. Labeling was specific in the Pvalb-Cre line with 87% of labeled interneurons immunopositive for parvalbumin (PV). Immunostaining for somatostatin (SOM) revealed good specificity in the X98 line with 89% of fluorescent cells, but a lesser specificity in Sst-Cre animals where only 71% of labeled cells were immunopositive. A minority of ∼6% of interneurons co-expressed PV and SOM in the presubiculum of Sst-Cre animals. The electrophysiological and morphological properties of fluorescent interneurons from Pvalb-Cre, Sst-Cre, and X98 mice differed. Distinct physiological groups of presubicular interneurons were resolved by unsupervised cluster analysis of parameters describing passive properties, firing patterns and AP shapes. One group consisted of SOM-positive, Martinotti type neurons with a low firing threshold (cluster 1). Fast spiking basket cells, mainly from the Pvalb-Cre line, formed a distinct group (cluster 3). Another group (cluster 2) contained interneurons of intermediate electrical properties and basket-cell like morphologies. These labeled neurons were recorded from both Sst-Cre and Pvalb-Cre animals. Thus, our results reveal a wide variation in anatomical and physiological properties for these interneurons, a real overlap of interneurons immuno-positive for both PV and SOM as well as an off-target recombination in the Sst-Cre line, possibly linked to maternal cre inheritance.
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Affiliation(s)
- Mérie Nassar
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
| | - Jean Simonnet
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
| | - Roxanne Lofredi
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
| | - Ivan Cohen
- Neuroscience Paris Seine Paris, Sorbonne Universités, UPMC Université Paris 06 UM CR 18, CNRS UMR 8246, INSERM U1130 Paris, France
| | - Etienne Savary
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine Maebashi, Japan ; Japan Science and Technology Agency Tokyo, Japan
| | - Richard Miles
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
| | - Desdemona Fricker
- Institut du Cerveau et de la Moelle Epinière, Sorbonne Universités, UPMC Université Paris 06 UM 75, CHU Pitié-Salpêtrière INSERM U1127, CNRS UMR7225 Paris, France
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108
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Sakakibara A, Hatanaka Y. Neuronal polarization in the developing cerebral cortex. Front Neurosci 2015; 9:116. [PMID: 25904841 PMCID: PMC4389351 DOI: 10.3389/fnins.2015.00116] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/22/2015] [Indexed: 12/17/2022] Open
Abstract
Cortical neurons consist of excitatory projection neurons and inhibitory GABAergic interneurons, whose connections construct highly organized neuronal circuits that control higher order information processing. Recent progress in live imaging has allowed us to examine how these neurons differentiate during development in vivo or in in vivo-like conditions. These analyses have revealed how the initial steps of polarization, in which neurons establish an axon, occur. Interestingly, both excitatory and inhibitory cortical neurons establish neuronal polarity de novo by undergoing a multipolar stage reminiscent of the manner in which polarity formation occurs in hippocampal neurons in dissociated culture. In this review, we focus on polarity formation in cortical neurons and describe their typical morphology and dynamic behavior during the polarization period. We also discuss cellular and molecular mechanisms underlying polarization, with reference to polarity formation in dissociated hippocampal neurons in vitro.
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Affiliation(s)
- Akira Sakakibara
- College of Life and Health Sciences, Chubu University Kasugai, Japan
| | - Yumiko Hatanaka
- Division of Cerebral Circuitry, National Institute for Physiological Sciences Okazaki, Japan ; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology Tokyo, Japan
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109
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Varga C, Tamas G, Barzo P, Olah S, Somogyi P. Molecular and Electrophysiological Characterization of GABAergic Interneurons Expressing the Transcription Factor COUP-TFII in the Adult Human Temporal Cortex. Cereb Cortex 2015; 25:4430-49. [PMID: 25787832 PMCID: PMC4768361 DOI: 10.1093/cercor/bhv045] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Transcription factors contribute to the differentiation of cortical neurons, orchestrate specific interneuronal circuits, and define synaptic relationships. We have investigated neurons expressing chicken ovalbumin upstream promoter transcription factor II (COUP-TFII), which plays a role in the migration of GABAergic neurons. Whole-cell, patch-clamp recording in vitro combined with colocalization of molecular cell markers in the adult cortex differentiates distinct interneurons. The majority of strongly COUP-TFII-expressing neurons were in layers I–III. Most calretinin (CR) and/or cholecystokinin- (CCK) and/or reelin-positive interneurons were also COUP-TFII-positive. CR-, CCK-, or reelin-positive neurons formed 80%, 20%, or 17% of COUP-TFII-positive interneurons, respectively. About half of COUP-TFII-/CCK-positive interneurons were CR-positive, a quarter of them reelin-positive, but none expressed both. Interneurons positive for COUP-TFII fired irregular, accommodating and adapting trains of action potentials (APs) and innervated mostly small dendritic shafts and rarely spines or somata. Paired recording showed that a calretinin-/COUP-TFII-positive interneuron elicited inhibitory postsynaptic potentials (IPSPs) in a reciprocally connected pyramidal cell. Calbindin, somatostatin, or parvalbumin-immunoreactive interneurons and most pyramidal cells express no immunohistochemically detectable COUP-TFII. In layers V and VI, some pyramidal cells expressed a low level of COUP-TFII in the nucleus. In conclusion, COUP-TFII is expressed in a diverse subset of GABAergic interneurons predominantly innervating small dendritic shafts originating from both interneurons and pyramidal cells.
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Affiliation(s)
- Csaba Varga
- Research Group for Cortical Microcircuits of the Hungarian Academy of Science, Department of Physiology, Anatomy and Neuroscience MRC, Brain Networks Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, UK Current address: Szentágothai Research Centre, Department of Physiology, University of Pécs, Pécs, Hungary
| | - Gabor Tamas
- Research Group for Cortical Microcircuits of the Hungarian Academy of Science, Department of Physiology, Anatomy and Neuroscience
| | - Pal Barzo
- Department of Neurosurgery, University of Szeged, Szeged, Hungary
| | - Szabolcs Olah
- Research Group for Cortical Microcircuits of the Hungarian Academy of Science, Department of Physiology, Anatomy and Neuroscience
| | - Peter Somogyi
- MRC, Brain Networks Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, UK Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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110
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Abstract
We describe recent progress toward defining neuronal cell types in the mouse retina and attempt to extract lessons that may be generally useful in the mammalian brain. Achieving a comprehensive catalog of retinal cell types now appears within reach, because researchers have achieved consensus concerning two fundamental challenges. The first is accuracy-defining pure cell types rather than settling for neuronal classes that are mixtures of types. The second is completeness-developing methods guaranteed to eventually identify all cell types, as well as criteria for determining when all types have been found. Case studies illustrate how these two challenges are handled by combining state-of-the-art molecular, anatomical, and physiological techniques. Progress is also being made in observing and modeling connectivity between cell types. Scaling up to larger brain regions, such as the cortex, will require not only technical advances but also careful consideration of the challenges of accuracy and completeness.
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111
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Reichel JM, Nissel S, Rogel-Salazar G, Mederer A, Käfer K, Bedenk BT, Martens H, Anders R, Grosche J, Michalski D, Härtig W, Wotjak CT. Distinct behavioral consequences of short-term and prolonged GABAergic depletion in prefrontal cortex and dorsal hippocampus. Front Behav Neurosci 2015; 8:452. [PMID: 25628548 PMCID: PMC4292780 DOI: 10.3389/fnbeh.2014.00452] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/17/2014] [Indexed: 11/13/2022] Open
Abstract
GABAergic interneurons are essential for a functional equilibrium between excitatory and inhibitory impulses throughout the CNS. Disruption of this equilibrium can lead to various neurological or neuropsychiatric disorders such as epilepsy or schizophrenia. Schizophrenia itself is clinically defined by negative (e.g., depression) and positive (e.g., hallucinations) symptoms as well as cognitive dysfunction. GABAergic interneurons are proposed to play a central role in the etiology and progression of schizophrenia; however, the specific mechanisms and the time-line of symptom development as well as the distinct involvement of cortical and hippocampal GABAergic interneurons in the etiology of schizophrenia-related symptoms are still not conclusively resolved. Previous work demonstrated that GABAergic interneurons can be selectively depleted in adult mice by means of saporin-conjugated anti-vesicular GABA transporter antibodies (SAVAs) in vitro and in vivo. Given their involvement in schizophrenia-related disease etiology, we ablated GABAergic interneurons in the medial prefrontal cortex (mPFC) and dorsal hippocampus (dHPC) in adult male C57BL/6N mice. Subsequently we assessed alterations in anxiety, sensory processing, hyperactivity and cognition after long-term (>14 days) and short-term (<14 days) GABAergic depletion. Long-term GABAergic depletion in the mPFC resulted in a decrease in sensorimotor-gating and impairments in cognitive flexibility. Notably, the same treatment at the level of the dHPC completely abolished spatial learning capabilities. Short-term GABAergic depletion in the dHPC revealed a transient hyperactive phenotype as well as marked impairments regarding the acquisition of a spatial memory. In contrast, recall of a spatial memory was not affected by the same intervention. These findings emphasize the importance of functional local GABAergic networks for the encoding but not the recall of hippocampus-dependent spatial memories.
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Affiliation(s)
- Judith M Reichel
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
| | - Sabine Nissel
- Paul Flechsig Institute for Brain Research, University of Leipzig Leipzig, Germany
| | - Gabriela Rogel-Salazar
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
| | - Anna Mederer
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
| | - Karola Käfer
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
| | - Benedikt T Bedenk
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
| | | | - Rebecca Anders
- Paul Flechsig Institute for Brain Research, University of Leipzig Leipzig, Germany
| | - Jens Grosche
- Paul Flechsig Institute for Brain Research, University of Leipzig Leipzig, Germany ; Effigos AG Leipzig, Germany
| | | | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig Leipzig, Germany
| | - Carsten T Wotjak
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Research Group "Neuronal Plasticity" Munich, Germany
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112
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Youssofzadeh V, Prasad G, Wong-Lin K. On self-feedback connectivity in neural mass models applied to event-related potentials. Neuroimage 2015; 108:364-76. [PMID: 25562823 DOI: 10.1016/j.neuroimage.2014.12.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 12/22/2014] [Accepted: 12/25/2014] [Indexed: 12/13/2022] Open
Abstract
Neural mass models (NMMs) applied to neuroimaging data often do not emphasise intrinsic self-feedback within a neural population. However, based on mean-field theory, any population of coupled neurons is intrinsically endowed with effective self-coupling. In this work, we examine the effectiveness of three cortical NMMs with different self-feedbacks using a dynamic causal modelling approach. Specifically, we compare the classic Jansen and Rit (1995) model (no self-feedback), a modified model by Moran et al. (2007) (only inhibitory self-feedback), and our proposed model with inhibitory and excitatory self-feedbacks. Using bifurcation analysis, we show that single-unit Jansen-Rit model is less robust in generating oscillatory behaviour than the other two models. Next, under Bayesian inversion, we simulate single-channel event-related potentials (ERPs) within a mismatch negativity auditory oddball paradigm. We found fully self-feedback model (FSM) to provide the best fit to single-channel data. By analysing the posterior covariances of model parameters, we show that self-feedback connections are less sensitive to the generated evoked responses than the other model parameters, and hence can be treated analogously to "higher-order" parameter corrections of the original Jansen-Rit model. This is further supported in the more realistic multi-area case where FSM can replicate data better than JRM and MoM in the majority of subjects by capturing the finer features of the ERP data more accurately. Our work informs how NMMs with full self-feedback connectivity are not only more consistent with the underlying neurophysiology, but can also account for more complex features in ERP data.
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Affiliation(s)
- Vahab Youssofzadeh
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster, Magee Campus, Northland Road, L'Derry BT48 7JL, UK
| | - Girijesh Prasad
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster, Magee Campus, Northland Road, L'Derry BT48 7JL, UK
| | - KongFatt Wong-Lin
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster, Magee Campus, Northland Road, L'Derry BT48 7JL, UK.
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113
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Hioki H. Compartmental organization of synaptic inputs to parvalbumin-expressing GABAergic neurons in mouse primary somatosensory cortex. Anat Sci Int 2014; 90:7-21. [PMID: 25467527 DOI: 10.1007/s12565-014-0264-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/17/2014] [Indexed: 12/19/2022]
Abstract
Parvalbumin (PV)-positive fast-spiking cells in the neocortex are known to generate gamma oscillations by mutual chemical and electrical connections. Recent findings suggest that this rhythm might be responsible for higher-order brain functions, and related to psychiatric disorders. To elucidate the precise structural rules of the connections of PV neurons, we first produced genetic tools. Using a lentiviral expression system, we developed neuron-specific promoters and a new reporter protein that labels the somatodendritic membrane of neurons. We applied the reporter protein to the generation of transgenic mice, and succeeded in visualizing the dendrites and cell bodies of PV neurons efficiently. Then we analyzed excitatory and inhibitory inputs to PV neurons in the primary somatosensory cortex using the mice. Corticocortical glutamatergic inputs were more frequently found on the distal dendrites than on the soma, whereas thalamocortical inputs did not differ between the proximal and distal portions. Corticocortical inhibitory inputs were more densely distributed on the soma than on the dendrites. We further investigated which types of neocortical GABAergic neurons preferred the PV soma over their dendrites. We revealed that the somatic and dendritic compartments principally received GABAergic inputs from vasoactive intestinal polypeptide (VIP)-positive and PV neurons, respectively. This compartmental organization suggests that PV neurons communicate with each other mainly via the dendrites, and that their activity is effectively controlled by the somatic inputs of VIP neurons. These findings provide new insights into the neuronal circuits involving PV neurons, and contribute to a better understanding of brain functions and mental disorders.
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Affiliation(s)
- Hiroyuki Hioki
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan,
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114
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Seney ML, Tripp A, McCune S, Lewis DA, Sibille E. Laminar and cellular analyses of reduced somatostatin gene expression in the subgenual anterior cingulate cortex in major depression. Neurobiol Dis 2014; 73:213-9. [PMID: 25315685 DOI: 10.1016/j.nbd.2014.10.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/08/2014] [Accepted: 10/02/2014] [Indexed: 02/05/2023] Open
Abstract
Somatostatin (SST), a neuropeptide expressed in dendritic-targeting gamma-aminobutyric acid (GABA) neurons, is decreased across corticolimbic areas in major depressive disorder (MDD). SST-positive GABA neurons form heterogeneous subgroups with different laminar distributions and electrophysiological properties, so knowing the anatomical and cellular localization of reduced SST may provide insight into the nature of the pathology in MDD. In cohorts of MDD subjects with known reduction of SST in postmortem sgACC gray matter, we used in situ hybridization to quantify the laminar and cellular patterns of altered SST mRNA expression. SST mRNA levels were lower across all cortical layers in the MDD subjects. Expression levels per cell were also lower, but the density of labeled neurons did not differ between subject groups. Consistent with the previous tissue level analysis, differences were more robust in females. In summary, we report MDD-related reduction in SST expression per cell across cortical layers in sgACC, suggesting a general vulnerability of SST neurons independent of specific cell type.
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Affiliation(s)
- Marianne L Seney
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Adam Tripp
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Samuel McCune
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Etienne Sibille
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; Campbell Family Research Institute, Centre for Addiction and Mental Health, Departments of Psychiatry, Pharmacology and Toxicology, University of Toronto, Toronto, Canada.
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115
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Lee AJ, Wang G, Jiang X, Johnson SM, Hoang ET, Lanté F, Stornetta RL, Beenhakker MP, Shen Y, Julius Zhu J. Canonical Organization of Layer 1 Neuron-Led Cortical Inhibitory and Disinhibitory Interneuronal Circuits. Cereb Cortex 2014; 25:2114-26. [PMID: 24554728 DOI: 10.1093/cercor/bhu020] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Interneurons play a key role in cortical function and dysfunction, yet organization of cortical interneuronal circuitry remains poorly understood. Cortical Layer 1 (L1) contains 2 general GABAergic interneuron groups, namely single bouquet cells (SBCs) and elongated neurogliaform cells (ENGCs). SBCs predominantly make unidirectional inhibitory connections (SBC→) with L2/3 interneurons, whereas ENGCs frequently form reciprocal inhibitory and electric connections (ENGC↔) with L2/3 interneurons. Here, we describe a systematic investigation of the pyramidal neuron targets of L1 neuron-led interneuronal circuits in the rat barrel cortex with simultaneous octuple whole-cell recordings and report a simple organizational scheme of the interneuronal circuits. Both SBCs→ and ENGC ↔ L2/3 interneuronal circuits connect to L2/3 and L5, but not L6, pyramidal neurons. SBC → L2/3 interneuronal circuits primarily inhibit the entire dendritic-somato-axonal axis of a few L2/3 and L5 pyramidal neurons located within the same column. In contrast, ENGC ↔ L2/3 interneuronal circuits generally inhibit the distal apical dendrite of many L2/3 and L5 pyramidal neurons across multiple columns. Finally, L1 interneuron-led circuits target distinct subcellular compartments of L2/3 and L5 pyramidal neurons in a L2/3 interneuron type-dependent manner. These results suggest that L1 neurons form canonical interneuronal circuits to control information processes in both supra- and infragranular cortical layers.
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Affiliation(s)
- Alice J Lee
- Department of Pharmacology Department of Biology
| | | | | | | | - Elizabeth T Hoang
- Department of Pharmacology Department of Psychology, School of Medicine and College of Arts and Sciences, University of Virginia, Charlottesville, VA 22908, USA
| | | | | | | | - Ying Shen
- Department of Neurobiology and Key Laboratory of Medical Neurobiology of Chinese Ministry of Health, Zhejiang University School of Medicine, 388 Yu Hang Tang Road, Hangzhou 310058, PR China
| | - J Julius Zhu
- Department of Pharmacology Department of Neuroscience
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