1
|
Kopsick JD, Kilgore JA, Adam GC, Ascoli GA. Formation and retrieval of cell assemblies in a biologically realistic spiking neural network model of area CA3 in the mouse hippocampus. J Comput Neurosci 2024; 52:303-321. [PMID: 39285088 PMCID: PMC11470887 DOI: 10.1007/s10827-024-00881-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 08/05/2024] [Accepted: 09/06/2024] [Indexed: 09/25/2024]
Abstract
The hippocampal formation is critical for episodic memory, with area Cornu Ammonis 3 (CA3) a necessary substrate for auto-associative pattern completion. Recent theoretical and experimental evidence suggests that the formation and retrieval of cell assemblies enable these functions. Yet, how cell assemblies are formed and retrieved in a full-scale spiking neural network (SNN) of CA3 that incorporates the observed diversity of neurons and connections within this circuit is not well understood. Here, we demonstrate that a data-driven SNN model quantitatively reflecting the neuron type-specific population sizes, intrinsic electrophysiology, connectivity statistics, synaptic signaling, and long-term plasticity of the mouse CA3 is capable of robust auto-association and pattern completion via cell assemblies. Our results show that a broad range of assembly sizes could successfully and systematically retrieve patterns from heavily incomplete or corrupted cues after a limited number of presentations. Furthermore, performance was robust with respect to partial overlap of assemblies through shared cells, substantially enhancing memory capacity. These novel findings provide computational evidence that the specific biological properties of the CA3 circuit produce an effective neural substrate for associative learning in the mammalian brain.
Collapse
Affiliation(s)
- Jeffrey D Kopsick
- Center for Neural Informatics, Structures, & Plasticity, College of Engineering and Computing, George Mason University, Fairfax, VA, USA
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, VA, USA
| | - Joseph A Kilgore
- Department of Electrical and Computer Engineering, George Washington University, Washington, D.C., USA
| | - Gina C Adam
- Department of Electrical and Computer Engineering, George Washington University, Washington, D.C., USA
| | - Giorgio A Ascoli
- Center for Neural Informatics, Structures, & Plasticity, College of Engineering and Computing, George Mason University, Fairfax, VA, USA.
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, VA, USA.
- Bioengineering Department, College of Engineering and Computing, George Mason University, Fairfax, VA, USA.
| |
Collapse
|
2
|
Joubert B. The neurobiology and immunology of CASPR2-associated neurological disorders. Rev Neurol (Paris) 2024:S0035-3787(24)00597-6. [PMID: 39341757 DOI: 10.1016/j.neurol.2024.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2024] [Accepted: 09/09/2024] [Indexed: 10/01/2024]
Abstract
CASPR2-associated neurological disorders encompass a wide clinical spectrum broadly divided into overlapping three autoimmune syndromes: CASPR2 limbic encephalitis, Morvan syndrome, and Isaacs syndrome. CASPR2 is a neuronal protein expressed at different sites in the central and peripheral nervous system and has a variety of roles and functions regarding neuronal excitability, synaptic plasticity, and homeostasis of inhibitory networks, most of which are only partially understood. CASPR2 antibodies have various pathogenic effects including internalization of CASPR2, disruption of protein-protein interactions, and, possibly, complement activation. Their pathogenic effect is well demonstrated in the limbic encephalitis phenotype, but the role of pathogenic antibodies in the development of other clinical manifestations is less clear. CASPR2 limbic encephalitis also differ from the other CASPR2-associated disorders in regard to HLA allele and paraneoplastic associations, suggesting it has immunological mechanisms distinct from the other clinical forms. Future studies are needed to better understand how the immunological alterations lead to the different phenotypes associated with CASPR2 antibodies.
Collapse
Affiliation(s)
- B Joubert
- Service de neurologie clinique et fonctionnelle, groupe hospitalier Sud, hospices civils de Lyon, Lyon, France; Centre de référence pour les encéphalites auto-immunes et les syndromes neurologiques paranéoplasiques, hospices civils de Lyon, Lyon, France.
| |
Collapse
|
3
|
Kopsick JD, Kilgore JA, Adam GC, Ascoli GA. Formation and Retrieval of Cell Assemblies in a Biologically Realistic Spiking Neural Network Model of Area CA3 in the Mouse Hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.586909. [PMID: 38585941 PMCID: PMC10996657 DOI: 10.1101/2024.03.27.586909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The hippocampal formation is critical for episodic memory, with area Cornu Ammonis 3 (CA3) a necessary substrate for auto-associative pattern completion. Recent theoretical and experimental evidence suggests that the formation and retrieval of cell assemblies enable these functions. Yet, how cell assemblies are formed and retrieved in a full-scale spiking neural network (SNN) of CA3 that incorporates the observed diversity of neurons and connections within this circuit is not well understood. Here, we demonstrate that a data-driven SNN model quantitatively reflecting the neuron type-specific population sizes, intrinsic electrophysiology, connectivity statistics, synaptic signaling, and long-term plasticity of the mouse CA3 is capable of robust auto-association and pattern completion via cell assemblies. Our results show that a broad range of assembly sizes could successfully and systematically retrieve patterns from heavily incomplete or corrupted cues after a limited number of presentations. Furthermore, performance was robust with respect to partial overlap of assemblies through shared cells, substantially enhancing memory capacity. These novel findings provide computational evidence that the specific biological properties of the CA3 circuit produce an effective neural substrate for associative learning in the mammalian brain.
Collapse
Affiliation(s)
- Jeffrey D. Kopsick
- Center for Neural Informatics, Structures, & Plasticity, College of Engineering and Computing, George Mason University, Fairfax, VA, United States
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, VA, United States
| | - Joseph A. Kilgore
- Department of Electrical and Computer Engineering, George Washington University, Washington, D.C., United States
| | - Gina C. Adam
- Department of Electrical and Computer Engineering, George Washington University, Washington, D.C., United States
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, & Plasticity, College of Engineering and Computing, George Mason University, Fairfax, VA, United States
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, VA, United States
- Bioengineering Department, College of Engineering and Computing, George Mason University, Fairfax, VA, United States
| |
Collapse
|
4
|
Fincham GW, Kartar A, Uthaug MV, Anderson B, Hall L, Nagai Y, Critchley H, Colasanti A. High ventilation breathwork practices: An overview of their effects, mechanisms, and considerations for clinical applications. Neurosci Biobehav Rev 2023; 155:105453. [PMID: 37923236 DOI: 10.1016/j.neubiorev.2023.105453] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/19/2023] [Accepted: 10/30/2023] [Indexed: 11/07/2023]
Abstract
High Ventilation Breathwork (HVB) refers to practices employing specific volitional manipulation of breathing, with a long history of use to relieve various forms of psychological distress. This paper seeks to offer a consolidative insight into potential clinical application of HVB as a treatment of psychiatric disorders. We thus review the characteristic phenomenological and neurophysiological effects of these practices to inform their mechanism of therapeutic action, safety profiles and future clinical applications. Clinical observations and data from neurophysiological studies indicate that HVB is associated with extraordinary changes in subjective experience, as well as with profound effects on central and autonomic nervous systems functions through modulation of neurometabolic parameters and interoceptive sensory systems. This growing evidence base may guide how the phenomenological effects of HVB can be understood, and potentially harnessed in the context of such volitional perturbation of psychophysiological state. Reports of putative beneficial effects for trauma-related, affective, and somatic disorders invite further research to obtain detailed mechanistic knowledge, and rigorous clinical testing of these potential therapeutic uses.
Collapse
Affiliation(s)
- Guy W Fincham
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK; University of Sussex, School of Psychology, Brighton, UK.
| | - Amy Kartar
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK
| | - Malin V Uthaug
- The Centre for Psychedelic Research, Division of Psychiatry, Imperial College London, UK; Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, The Netherlands
| | - Brittany Anderson
- University of Wisconsin School of Medicine & Public Health, Department of Psychiatry, University of Wisconsin-Madison, USA
| | - Lottie Hall
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK
| | - Yoko Nagai
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK
| | - Hugo Critchley
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK
| | - Alessandro Colasanti
- Brighton & Sussex Medical School, Department of Neuroscience, University of Sussex, UK; Sussex Partnership NHS Foundation Trust.
| |
Collapse
|
5
|
Michon FX, Laplante I, Bosson A, Robitaille R, Lacaille JC. mTORC1-mediated acquisition of reward-related representations by hippocampal somatostatin interneurons. Mol Brain 2023; 16:55. [PMID: 37400913 DOI: 10.1186/s13041-023-01042-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/03/2023] [Indexed: 07/05/2023] Open
Abstract
Plasticity of principal cells and inhibitory interneurons underlies hippocampal memory. Bidirectional modulation of somatostatin cell mTORC1 activity, a crucial translational control mechanism in synaptic plasticity, causes parallel changes in hippocampal CA1 somatostatin interneuron (SOM-IN) long-term potentiation and hippocampus-dependent memory, indicating a key role in learning. However, SOM-IN activity changes and behavioral correlates during learning, and the role of mTORC1 in these processes, remain ill-defined. To address these questions, we used two-photon Ca2+ imaging from SOM-INs during a virtual reality goal-directed spatial memory task in head-fixed control mice (SOM-IRES-Cre mice) or in mice with conditional knockout of Rptor (SOM-Rptor-KO mice) to block mTORC1 activity in SOM-INs. We found that control mice learn the task, but SOM-Raptor-KO mice exhibit a deficit. Also, SOM-IN Ca2+ activity became increasingly related to reward during learning in control mice but not in SOM-Rptor-KO mice. Four types of SOM-IN activity patterns related to reward location were observed, "reward off sustained", "reward off transient", "reward on sustained" and "reward on transient", and these responses showed reorganization after reward relocation in control but not SOM-Rptor-KO mice. Thus, SOM-INs develop mTORC1-dependent reward- related activity during learning. This coding may bi-directionally interact with pyramidal cells and other structures to represent and consolidate reward location.
Collapse
Affiliation(s)
- François-Xavier Michon
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Isabel Laplante
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Anthony Bosson
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Richard Robitaille
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Jean-Claude Lacaille
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada.
| |
Collapse
|
6
|
Kopsick JD, Tecuatl C, Moradi K, Attili SM, Kashyap HJ, Xing J, Chen K, Krichmar JL, Ascoli GA. Robust Resting-State Dynamics in a Large-Scale Spiking Neural Network Model of Area CA3 in the Mouse Hippocampus. Cognit Comput 2023; 15:1190-1210. [PMID: 37663748 PMCID: PMC10473858 DOI: 10.1007/s12559-021-09954-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 10/10/2021] [Indexed: 12/19/2022]
Abstract
Hippocampal area CA3 performs the critical auto-associative function underlying pattern completion in episodic memory. Without external inputs, the electrical activity of this neural circuit reflects the spontaneous spiking interplay among glutamatergic pyramidal neurons and GABAergic interneurons. However, the network mechanisms underlying these resting-state firing patterns are poorly understood. Leveraging the Hippocampome.org knowledge base, we developed a data-driven, large-scale spiking neural network (SNN) model of mouse CA3 with 8 neuron types, 90,000 neurons, 51 neuron-type specific connections, and 250,000,000 synapses. We instantiated the SNN in the CARLsim4 multi-GPU simulation environment using the Izhikevich and Tsodyks-Markram formalisms for neuronal and synaptic dynamics, respectively. We analyzed the resultant population activity upon transient activation. The SNN settled into stable oscillations with a biologically plausible grand-average firing frequency, which was robust relative to a wide range of transient activation. The diverse firing patterns of individual neuron types were consistent with existing knowledge of cell type-specific activity in vivo. Altered network structures that lacked neuron- or connection-type specificity were neither stable nor robust, highlighting the importance of neuron type circuitry. Additionally, external inputs reflecting dentate mossy fibers shifted the observed rhythms to the gamma band. We freely released the CARLsim4-Hippocampome framework on GitHub to test hippocampal hypotheses. Our SNN may be useful to investigate the circuit mechanisms underlying the computational functions of CA3. Moreover, our approach can be scaled to the whole hippocampal formation, which may contribute to elucidating how the unique neuronal architecture of this system subserves its crucial cognitive roles.
Collapse
Affiliation(s)
- Jeffrey D. Kopsick
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Carolina Tecuatl
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
| | - Keivan Moradi
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Sarojini M. Attili
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Hirak J. Kashyap
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA
| | - Jinwei Xing
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
| | - Kexin Chen
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
| | - Jeffrey L. Krichmar
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA
| | - Giorgio A. Ascoli
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
| |
Collapse
|
7
|
Liu M, Sun X. Spatial integration of dendrites in fast-spiking basket cells. Front Neurosci 2023; 17:1132980. [PMID: 37081933 PMCID: PMC10110864 DOI: 10.3389/fnins.2023.1132980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
Dendrites of fast-spiking basket cells (FS BCs) impact neural circuit functions in brain with both supralinear and sublinear integration strategies. Diverse spatial synaptic inputs and active properties of dendrites lead to distinct neuronal firing patterns. How the FS BCs with this bi-modal dendritic integration respond to different spatial dispersion of synaptic inputs remains unclear. In this study, we construct a multi-compartmental model of FS BC and analyze neuronal firings following simulated synaptic protocols from fully clustered to fully dispersed. Under these stimulation protocols, we find that supralinear dendrites dominate somatic firing of FS BC, while the preference for dispersing is due to sublinear dendrites. Moreover, we find that dendritic diameter and Ca2+-permeable AMPA conductance play an important role in it, while A-type K+ channel and NMDA conductance have little effect. The obtained results may give some implications for understanding dendritic computation.
Collapse
|
8
|
Barrutieta-Arberas I, Ortuzar N, Vaquero-Rodríguez A, Picó-Gallardo M, Bengoetxea H, Guevara MA, Gargiulo PA, Lafuente JV. The role of ketamine in major depressive disorders: Effects on parvalbumin-positive interneurons in hippocampus. Exp Biol Med (Maywood) 2023; 248:588-595. [PMID: 37158084 PMCID: PMC10350797 DOI: 10.1177/15353702231170007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Major depressive disorder (MDD) is a complex illness that is arising as a growing public health concern. Although several brain areas are related to this type of disorders, at the cellular level, the parvalbumin-positive cells of the hippocampus interplay a very relevant role. They control pyramidal cell bursts, neuronal networks, basic microcircuit functions, and other complex neuronal tasks involved in mood disorders. In resistant depressions, the efficacy of current antidepressant treatments drops dramatically, so the new rapid-acting antidepressants (RAADs) are being postulated as novel treatments. Ketamine at subanesthetic doses and its derivative metabolites have been proposed as RAADs due to their rapid and sustained action by blocking N-methyl-d-aspartate (NMDA) receptors, which in turn lead to the release of brain-derived neurotrophic factor (BDNF). This mechanism produces a rapid plasticity activation mediated by neurotransmitter homeostasis, synapse recovery, and increased dendritic spines and therefore, it is a promising therapeutic approach to improve cognitive symptoms in MDD.
Collapse
Affiliation(s)
- I Barrutieta-Arberas
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - N Ortuzar
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
- Neurodegenerative Diseases Group, BioCruces Health Research Institute, 48903 Barakaldo, Spain
| | - A Vaquero-Rodríguez
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
- Neurodegenerative Diseases Group, BioCruces Health Research Institute, 48903 Barakaldo, Spain
| | - M Picó-Gallardo
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - H Bengoetxea
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
- Neurodegenerative Diseases Group, BioCruces Health Research Institute, 48903 Barakaldo, Spain
| | - MA Guevara
- Laboratory of Neurosciences and Experimental Psychology, Area of Pharmacology, Department of Pathology, Faculty of Medical Sciences, National Council of Scientific and Technical Research, National University of Cuyo, 5502 Mendoza, Argentina
| | - PA Gargiulo
- Laboratory of Neurosciences and Experimental Psychology, Area of Pharmacology, Department of Pathology, Faculty of Medical Sciences, National Council of Scientific and Technical Research, National University of Cuyo, 5502 Mendoza, Argentina
| | - JV Lafuente
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
- Neurodegenerative Diseases Group, BioCruces Health Research Institute, 48903 Barakaldo, Spain
| |
Collapse
|
9
|
Vancura B, Geiller T, Losonczy A. Organization and Plasticity of Inhibition in Hippocampal Recurrent Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532296. [PMID: 36993553 PMCID: PMC10054977 DOI: 10.1101/2023.03.13.532296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Excitatory-inhibitory interactions structure recurrent network dynamics for efficient cortical computations. In the CA3 area of the hippocampus, recurrent circuit dynamics, including experience-induced plasticity at excitatory synapses, are thought to play a key role in episodic memory encoding and consolidation via rapid generation and flexible selection of neural ensembles. However, in vivo activity of identified inhibitory motifs supporting this recurrent circuitry has remained largely inaccessible, and it is unknown whether CA3 inhibition is also modifiable upon experience. Here we use large-scale, 3-dimensional calcium imaging and retrospective molecular identification in the mouse hippocampus to obtain the first comprehensive description of molecularly-identified CA3 interneuron dynamics during both spatial navigation and sharp-wave ripple (SWR)-associated memory consolidation. Our results uncover subtype-specific dynamics during behaviorally distinct brain-states. Our data also demonstrate predictive, reflective, and experience-driven plastic recruitment of specific inhibitory motifs during SWR-related memory reactivation. Together these results assign active roles for inhibitory circuits in coordinating operations and plasticity in hippocampal recurrent circuits.
Collapse
|
10
|
Guardamagna M, Stella F, Battaglia FP. Heterogeneity of network and coding states in mouse CA1 place cells. Cell Rep 2023; 42:112022. [PMID: 36709427 DOI: 10.1016/j.celrep.2023.112022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/20/2022] [Accepted: 01/06/2023] [Indexed: 01/29/2023] Open
Abstract
Theta sequences and phase precession shape hippocampal activity and are considered key underpinnings of memory formation. Theta sequences are sweeps of spikes from multiple cells, tracing trajectories from past to future. Phase precession is the correlation between theta firing phase and animal position. Here, we reconsider these temporal processes in CA1 and the computational principles that they are thought to obey. We find stronger heterogeneity than previously described: we identify cells that do not phase precess but reliably express theta sequences. Other cells phase precess only when medium gamma (linked to entorhinal inputs) is strongest. The same cells express more sequences, but not precession, when slow gamma (linked to CA3 inputs) dominates. Moreover, sequences occur independently in distinct cell groups. Our results challenge the view that phase precession is the mechanism underlying the emergence of theta sequences, suggesting a role for CA1 cells in multiplexing diverse computational processes.
Collapse
Affiliation(s)
- Matteo Guardamagna
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Federico Stella
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Francesco P Battaglia
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
| |
Collapse
|
11
|
Mysin I, Shubina L. Hippocampal non-theta state: The "Janus face" of information processing. Front Neural Circuits 2023; 17:1134705. [PMID: 36960401 PMCID: PMC10027749 DOI: 10.3389/fncir.2023.1134705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
The vast majority of studies on hippocampal rhythms have been conducted on animals or humans in situations where their attention was focused on external stimuli or solving cognitive tasks. These studies formed the basis for the idea that rhythmical activity coordinates the work of neurons during information processing. However, at rest, when attention is not directed to external stimuli, brain rhythms do not disappear, although the parameters of oscillatory activity change. What is the functional load of rhythmical activity at rest? Hippocampal oscillatory activity during rest is called the non-theta state, as opposed to the theta state, a characteristic activity during active behavior. We dedicate our review to discussing the present state of the art in the research of the non-theta state. The key provisions of the review are as follows: (1) the non-theta state has its own characteristics of oscillatory and neuronal activity; (2) hippocampal non-theta state is possibly caused and maintained by change of rhythmicity of medial septal input under the influence of raphe nuclei; (3) there is no consensus in the literature about cognitive functions of the non-theta-non-ripple state; and (4) the antagonistic relationship between theta and delta rhythms observed in rodents is not always observed in humans. Most attention is paid to the non-theta-non-ripple state, since this aspect of hippocampal activity has not been investigated properly and discussed in reviews.
Collapse
|
12
|
Kajikawa K, Hulse BK, Siapas AG, Lubenov EV. UP-DOWN states and ripples differentially modulate membrane potential dynamics across DG, CA3, and CA1 in awake mice. eLife 2022; 11:69596. [PMID: 35819409 PMCID: PMC9275824 DOI: 10.7554/elife.69596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/02/2022] [Indexed: 11/25/2022] Open
Abstract
Hippocampal ripples are transient population bursts that structure cortico-hippocampal communication and play a central role in memory processing. However, the mechanisms controlling ripple initiation in behaving animals remain poorly understood. Here we combine multisite extracellular and whole-cell recordings in awake mice to contrast the brain state and ripple modulation of subthreshold dynamics across hippocampal subfields. We find that entorhinal input to the dentate gyrus (DG) exhibits UP and DOWN dynamics with ripples occurring exclusively in UP states. While elevated cortical input in UP states generates depolarization in DG and CA1, it produces persistent hyperpolarization in CA3 neurons. Furthermore, growing inhibition is evident in CA3 throughout the course of the ripple buildup, while DG and CA1 neurons exhibit depolarization transients 100 ms before and during ripples. These observations highlight the importance of CA3 inhibition for ripple generation, while pre-ripple responses indicate a long and orchestrated ripple initiation process in the awake state.
Collapse
Affiliation(s)
- Koichiro Kajikawa
- Division of Biology and Biological Engineering, Division of Engineering and Applied Science, Computation and Neural Systems Program, California Institute of Technology, Pasadena, United States
| | - Brad K Hulse
- Division of Biology and Biological Engineering, Division of Engineering and Applied Science, Computation and Neural Systems Program, California Institute of Technology, Pasadena, United States
| | - Athanassios G Siapas
- Division of Biology and Biological Engineering, Division of Engineering and Applied Science, Computation and Neural Systems Program, California Institute of Technology, Pasadena, United States
| | - Evgueniy V Lubenov
- Division of Biology and Biological Engineering, Division of Engineering and Applied Science, Computation and Neural Systems Program, California Institute of Technology, Pasadena, United States
| |
Collapse
|
13
|
Khalife MR, Scott RC, Hernan AE. Mechanisms for Cognitive Impairment in Epilepsy: Moving Beyond Seizures. Front Neurol 2022; 13:878991. [PMID: 35645970 PMCID: PMC9135108 DOI: 10.3389/fneur.2022.878991] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
There has been a major emphasis on defining the role of seizures in the causation of cognitive impairments like memory deficits in epilepsy. Here we focus on an alternative hypothesis behind these deficits, emphasizing the mechanisms of information processing underlying healthy cognition characterized as rate, temporal and population coding. We discuss the role of the underlying etiology of epilepsy in altering neural networks thereby leading to both the propensity for seizures and the associated cognitive impairments. In addition, we address potential treatments that can recover the network function in the context of a diseased brain, thereby improving both seizure and cognitive outcomes simultaneously. This review shows the importance of moving beyond seizures and approaching the deficits from a system-level perspective with the guidance of network neuroscience.
Collapse
Affiliation(s)
- Mohamed R. Khalife
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Rod C. Scott
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
- Institute of Child Health, Neurosciences Unit University College London, London, United Kingdom
| | - Amanda E. Hernan
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| |
Collapse
|
14
|
Pinna A, Colasanti A. The Neurometabolic Basis of Mood Instability: The Parvalbumin Interneuron Link-A Systematic Review and Meta-Analysis. Front Pharmacol 2021; 12:689473. [PMID: 34616292 PMCID: PMC8488267 DOI: 10.3389/fphar.2021.689473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/18/2021] [Indexed: 12/23/2022] Open
Abstract
The neurobiological bases of mood instability are poorly understood. Neuronal network alterations and neurometabolic abnormalities have been implicated in the pathophysiology of mood and anxiety conditions associated with mood instability and hence are candidate mechanisms underlying its neurobiology. Fast-spiking parvalbumin GABAergic interneurons modulate the activity of principal excitatory neurons through their inhibitory action determining precise neuronal excitation balance. These interneurons are directly involved in generating neuronal networks activities responsible for sustaining higher cerebral functions and are especially vulnerable to metabolic stress associated with deficiency of energy substrates or mitochondrial dysfunction. Parvalbumin interneurons are therefore candidate key players involved in mechanisms underlying the pathogenesis of brain disorders associated with both neuronal networks' dysfunction and brain metabolism dysregulation. To provide empirical support to this hypothesis, we hereby report meta-analytical evidence of parvalbumin interneurons loss or dysfunction in the brain of patients with Bipolar Affective Disorder (BPAD), a condition primarily characterized by mood instability for which the pathophysiological role of mitochondrial dysfunction has recently emerged as critically important. We then present a comprehensive review of evidence from the literature illustrating the bidirectional relationship between deficiency in mitochondrial-dependent energy production and parvalbumin interneuron abnormalities. We propose a mechanistic explanation of how alterations in neuronal excitability, resulting from parvalbumin interneurons loss or dysfunction, might manifest clinically as mood instability, a poorly understood clinical phenotype typical of the most severe forms of affective disorders. The evidence we report provides insights on the broader therapeutic potential of pharmacologically targeting parvalbumin interneurons in psychiatric and neurological conditions characterized by both neurometabolic and neuroexcitability abnormalities.
Collapse
Affiliation(s)
- Antonello Pinna
- School of Life Sciences, University of Sussex, Brighton, United Kingdom.,Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Alessandro Colasanti
- Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| |
Collapse
|
15
|
Li Z, Li J, Wang S, Wang X, Chen J, Qin L. Laminar Profile of Auditory Steady-State Response in the Auditory Cortex of Awake Mice. Front Syst Neurosci 2021; 15:636395. [PMID: 33815073 PMCID: PMC8017131 DOI: 10.3389/fnsys.2021.636395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/19/2021] [Indexed: 12/20/2022] Open
Abstract
Objective Auditory steady-state response (ASSR) is a gamma oscillation evoked by periodic auditory stimuli, which is commonly used in clinical electroencephalographic examination to evaluate the neurological functions. Though it has been suggested that auditory cortex is the origin of ASSR, how the laminar architecture of the neocortex contributes to the ASSR recorded from the brain surface remains unclear. Methods We used a 16-channel silicon probe to record the local field potential and the single-unit spike activity in the different layers of the auditory cortex of unanesthetized mice. Click-trains with a repetition rate at 40-Hz were present as sound stimuli to evoke ASSR. Results We found that the LFPs of all cortical layers showed a stable ASSR synchronizing to the 40-Hz click stimuli, while the ASSR was strongest in the granular (thalamorecipient) layer. Furthermore, time-frequency analyses also revealed the strongest coherence between the signals recorded from the granular layer and pial surface. Conclusion Our results reveal that the 40-Hz ASSR primarily shows the evoked gamma oscillation of thalamorecipient layers in the neocortex, and that the ASSR may be a biomarker to detect the cognitive deficits associated with impaired thalamo-cortical connection.
Collapse
Affiliation(s)
- Zijie Li
- Department of Physiology, China Medical University, Shenyang, China
| | - Jinhong Li
- Department of Physiology, China Medical University, Shenyang, China
| | - Shuai Wang
- Department of Physiology, China Medical University, Shenyang, China
| | - Xuejiao Wang
- Department of Physiology, China Medical University, Shenyang, China
| | - Jingyu Chen
- Department of Physiology, China Medical University, Shenyang, China
| | - Ling Qin
- Department of Physiology, China Medical University, Shenyang, China
| |
Collapse
|
16
|
Mazuir E, Fricker D, Sol-Foulon N. Neuron-Oligodendrocyte Communication in Myelination of Cortical GABAergic Cells. Life (Basel) 2021; 11:216. [PMID: 33803153 PMCID: PMC7999565 DOI: 10.3390/life11030216] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 11/17/2022] Open
Abstract
Axonal myelination by oligodendrocytes increases the speed and reliability of action potential propagation, and so plays a pivotal role in cortical information processing. The extent and profile of myelination vary between different cortical layers and groups of neurons. Two subtypes of cortical GABAergic neurons are myelinated: fast-spiking parvalbumin-expressing cells and somatostatin-containing cells. The expression of pre-nodes on the axon of these inhibitory cells before myelination illuminates communication between oligodendrocytes and neurons. We explore the consequences of myelination for action potential propagation, for patterns of neuronal connectivity and for the expression of behavioral plasticity.
Collapse
Affiliation(s)
- Elisa Mazuir
- Inserm, CNRS, Paris Brain Institute, ICM, Sorbonne University, Pitié-Salpêtrière Hospital, F-75013 Paris, France
| | - Desdemona Fricker
- CNRS UMR 8002, Integrative Neuroscience and Cognition Center, Université de Paris, F-75006 Paris, France
| | - Nathalie Sol-Foulon
- Inserm, CNRS, Paris Brain Institute, ICM, Sorbonne University, Pitié-Salpêtrière Hospital, F-75013 Paris, France
| |
Collapse
|
17
|
Parvalbumin and Somatostatin Interneurons Contribute to the Generation of Hippocampal Gamma Oscillations. J Neurosci 2020; 40:7668-7687. [PMID: 32859716 PMCID: PMC7531548 DOI: 10.1523/jneurosci.0261-20.2020] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 11/22/2022] Open
Abstract
γ-frequency oscillations (30-120 Hz) in cortical networks influence neuronal encoding and information transfer, and are disrupted in multiple brain disorders. While synaptic inhibition is important for synchronization across the γ-frequency range, the role of distinct interneuronal subtypes in slow (<60 Hz) and fast γ states remains unclear. Here, we used optogenetics to examine the involvement of parvalbumin-expressing (PV+) and somatostatin-expressing (SST+) interneurons in γ oscillations in the mouse hippocampal CA3 ex vivo, using animals of either sex. Disrupting either PV+ or SST+ interneuron activity, via either photoinhibition or photoexcitation, led to a decrease in the power of cholinergically induced slow γ oscillations. Furthermore, photoexcitation of SST+ interneurons induced fast γ oscillations, which depended on both synaptic excitation and inhibition. Our findings support a critical role for both PV+ and SST+ interneurons in slow hippocampal γ oscillations, and further suggest that intense activation of SST+ interneurons can enable the CA3 circuit to generate fast γ oscillations. SIGNIFICANCE STATEMENT The generation of hippocampal γ oscillations depends on synchronized inhibition provided by GABAergic interneurons. Parvalbumin-expressing (PV+) interneurons are thought to play the key role in coordinating the spike timing of excitatory pyramidal neurons, but the role distinct inhibitory circuits in network synchronization remains unresolved. Here, we show, for the first time, that causal disruption of either PV+ or somatostatin-expressing (SST+) interneuron activity impairs the generation of slow γ oscillations in the ventral hippocampus ex vivo. We further show that SST+ interneuron activation along with general network excitation is sufficient to generate high-frequency γ oscillations in the same preparation. These results affirm a crucial role for both PV+ and SST+ interneurons in hippocampal γ oscillation generation.
Collapse
|
18
|
Bertero A, Zurita H, Normandin M, Apicella AJ. Auditory Long-Range Parvalbumin Cortico-Striatal Neurons. Front Neural Circuits 2020; 14:45. [PMID: 32792912 PMCID: PMC7390902 DOI: 10.3389/fncir.2020.00045] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/29/2020] [Indexed: 11/13/2022] Open
Abstract
Previous studies have shown that cortico-striatal pathways link auditory signals to action-selection and reward-learning behavior through excitatory projections. Only recently it has been demonstrated that long-range GABAergic cortico-striatal somatostatin-expressing neurons in the auditory cortex project to the dorsal striatum, and functionally inhibit the main projecting neuronal population, the spiny projecting neuron. Here we tested the hypothesis that parvalbumin-expressing neurons of the auditory cortex can also send long-range projections to the auditory striatum. To address this fundamental question, we took advantage of viral and non-viral anatomical tracing approaches to identify cortico-striatal parvalbumin neurons (CS-Parv inhibitory projections → auditory striatum). Here, we describe their anatomical distribution in the auditory cortex and determine the anatomical and electrophysiological properties of layer 5 CS-Parv neurons. We also analyzed their characteristic voltage-dependent membrane potential gamma oscillation, showing that intrinsic membrane mechanisms generate them. The inherent membrane mechanisms can also trigger intermittent and irregular bursts (stuttering) of the action potential in response to steps of depolarizing current pulses.
Collapse
Affiliation(s)
- Alice Bertero
- Department of Biology, Neurosciences Institute, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Hector Zurita
- Department of Biology, Neurosciences Institute, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Marc Normandin
- Department of Biology, Neurosciences Institute, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Alfonso Junior Apicella
- Department of Biology, Neurosciences Institute, The University of Texas at San Antonio, San Antonio, TX, United States
| |
Collapse
|
19
|
Capogna M, Castillo PE, Maffei A. The ins and outs of inhibitory synaptic plasticity: Neuron types, molecular mechanisms and functional roles. Eur J Neurosci 2020; 54:6882-6901. [PMID: 32663353 DOI: 10.1111/ejn.14907] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023]
Abstract
GABAergic interneurons are highly diverse, and their synaptic outputs express various forms of plasticity. Compelling evidence indicates that activity-dependent changes of inhibitory synaptic transmission play a significant role in regulating neural circuits critically involved in learning and memory and circuit refinement. Here, we provide an updated overview of inhibitory synaptic plasticity with a focus on the hippocampus and neocortex. To illustrate the diversity of inhibitory interneurons, we discuss the case of two highly divergent interneuron types, parvalbumin-expressing basket cells and neurogliaform cells, which support unique roles on circuit dynamics. We also present recent progress on the molecular mechanisms underlying long-term, activity-dependent plasticity of fast inhibitory transmission. Lastly, we discuss the role of inhibitory synaptic plasticity in neuronal circuits' function. The emerging picture is that inhibitory synaptic transmission in the CNS is extremely diverse, undergoes various mechanistically distinct forms of plasticity and contributes to a much more refined computational role than initially thought. Both the remarkable diversity of inhibitory interneurons and the various forms of plasticity expressed by GABAergic synapses provide an amazingly rich inhibitory repertoire that is central to a variety of complex neural circuit functions, including memory.
Collapse
Affiliation(s)
- Marco Capogna
- Department of Biomedicine, Danish National Research Foundation Center of Excellence PROMEMO, Aarhus University, Aarhus, Denmark
| | - Pablo E Castillo
- Dominck P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arianna Maffei
- Center for Neural Circuit Dynamics and Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| |
Collapse
|
20
|
Cho KKA, Davidson TJ, Bouvier G, Marshall JD, Schnitzer MJ, Sohal VS. Cross-hemispheric gamma synchrony between prefrontal parvalbumin interneurons supports behavioral adaptation during rule shift learning. Nat Neurosci 2020; 23:892-902. [PMID: 32451483 PMCID: PMC7347248 DOI: 10.1038/s41593-020-0647-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
Organisms must learn new strategies to adapt to changing environments. Activity in different neurons often exhibits synchronization that can dynamically enhance their communication and might create flexible brain states that facilitate changes in behavior. We studied the role of gamma-frequency (~40 Hz) synchrony between prefrontal parvalbumin (PV) interneurons in mice learning multiple new cue-reward associations. Voltage indicators revealed cell-type-specific increases of cross-hemispheric gamma synchrony between PV interneurons when mice received feedback that previously learned associations were no longer valid. Disrupting this synchronization by delivering out-of-phase optogenetic stimulation caused mice to perseverate on outdated associations, an effect not reproduced by in-phase stimulation or out-of-phase stimulation at other frequencies. Gamma synchrony was specifically required when new associations used familiar cues that were previously irrelevant to behavioral outcomes, not when associations involved new cues or for reversing previously learned associations. Thus, gamma synchrony is indispensable for reappraising the behavioral salience of external cues.
Collapse
Affiliation(s)
- Kathleen K A Cho
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - Thomas J Davidson
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, San Francisco, CA, USA
| | - Guy Bouvier
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, San Francisco, CA, USA
| | - Jesse D Marshall
- Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Mark J Schnitzer
- Departments of Biology and Applied Physics, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Vikaas S Sohal
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA.
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA.
- Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA.
| |
Collapse
|
21
|
Bartholome O, de la Brassinne Bonardeaux O, Neirinckx V, Rogister B. A Composite Sketch of Fast-Spiking Parvalbumin-Positive Neurons. Cereb Cortex Commun 2020; 1:tgaa026. [PMID: 34296100 PMCID: PMC8153048 DOI: 10.1093/texcom/tgaa026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/15/2020] [Accepted: 06/15/2020] [Indexed: 01/28/2023] Open
Abstract
Parvalbumin-positive neurons are inhibitory neurons that release GABA and are mostly represented by fast-spiking basket or chandelier cells. They constitute a minor neuronal population, yet their peculiar profiles allow them to react quickly to any event in the brain under normal or pathological conditions. In this review, we will summarize the current knowledge about the fundamentals of fast-spiking parvalbumin-positive neurons, focusing on their morphology and specific channel/protein content. Next, we will explore their development, maturation, and migration in the brain. Finally, we will unravel their potential contribution to the physiopathology of epilepsy.
Collapse
Affiliation(s)
| | | | | | - Bernard Rogister
- GIGA-Neurosciences, University of Liege, 4000 Liège, Belgium
- Neurology Department, CHU, Academic Hospital, University of Liege, 4000 Liège, Belgium
| |
Collapse
|
22
|
Shunting Inhibition Improves Synchronization in Heterogeneous Inhibitory Interneuronal Networks with Type 1 Excitability Whereas Hyperpolarizing Inhibition Is Better for Type 2 Excitability. eNeuro 2020; 7:ENEURO.0464-19.2020. [PMID: 32198159 PMCID: PMC7210489 DOI: 10.1523/eneuro.0464-19.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/01/2020] [Accepted: 03/10/2020] [Indexed: 11/27/2022] Open
Abstract
All-to-all homogeneous networks of inhibitory neurons synchronize completely under the right conditions; however, many modeling studies have shown that biological levels of heterogeneity disrupt synchrony. Our fundamental scientific question is “how can neurons maintain partial synchrony in the presence of heterogeneity and noise?” A particular subset of strongly interconnected interneurons, the PV+ fast-spiking (FS) basket neurons, are strongly implicated in γ oscillations and in phase locking of nested γ oscillations to theta. Their excitability type apparently varies between brain regions: in CA1 and the dentate gyrus they have type 1 excitability, meaning that they can fire arbitrarily slowly, whereas in the striatum and cortex they have type 2 excitability, meaning that there is a frequency thresh old below which they cannot sustain repetitive firing. We constrained the models to study the effect of excitability type (more precisely bifurcation type) in isolation from all other factors. We use sparsely connected, heterogeneous, noisy networks with synaptic delays to show that synchronization properties, namely the resistance to suppression and the strength of theta phase to γ amplitude coupling, are strongly dependent on the pairing of excitability type with the type of inhibition. Shunting inhibition performs better for type 1 and hyperpolarizing inhibition for type 2. γ Oscillations and their nesting within theta oscillations are thought to subserve cognitive functions like memory encoding and recall; therefore, it is important to understand the contribution of intrinsic properties to these rhythms.
Collapse
|
23
|
Bazin M, Purohit NK, Merlin MA, Shah GM. A panel of criteria for comprehensive assessment of severity of ultraviolet B radiation-induced non-melanoma skin cancers in SKH-1 mice. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 205:111847. [PMID: 32172138 DOI: 10.1016/j.jphotobiol.2020.111847] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 02/18/2020] [Accepted: 03/03/2020] [Indexed: 11/19/2022]
Abstract
The study of causes and cures for ultraviolet B radiation (UVB)-induced non-melanoma skin cancers (NMSC) has been greatly facilitated by use of the albino SKH-1 hairless mice. These mice develop multiple tumors of different sizes and the severity of cancer is often measured by one or more of the four criteria, namely the prevalence, multiplicity, area and volume of tumors. However, there are inherent limitations of each criterion: the prevalence and number do not account for size differences among tumors, area measurement ignores the tumor height, and volume measurement overcompensates for the height at the cost of planar dimensions. Here, using our dataset from an ongoing NMSC study, we discuss the limitations of these four criteria, and suggest refinements in measuring prevalence. We recommend the use of three more criteria, namely the Knud Thomsen tridimensional surface that apportions optimal weightage to three tumor dimensions, weekly occurrence of new tumors and tumor growth-rate to reveal initiation and growth of tumors in early and late phase of NMSC development, respectively. Together, use of this comprehensive panel of seven criteria can provide an accurate assessment of severity of NMSC and lead to a testable hypothesis whether the experimental manipulation of mice has affected the early initiation or growth phase of NMSC tumors.
Collapse
Affiliation(s)
- Marc Bazin
- CHU de Quebec-Laval University Research Center, Neuroscience and Cancer Axes, Laboratory for Skin Cancer Research, 2705, Boulevard Laurier, Quebec (QC), Canada; Université Laval Cancer Research Center, Quebec (QC), Canada
| | - Nupur K Purohit
- CHU de Quebec-Laval University Research Center, Neuroscience and Cancer Axes, Laboratory for Skin Cancer Research, 2705, Boulevard Laurier, Quebec (QC), Canada; Université Laval Cancer Research Center, Quebec (QC), Canada
| | - Marine A Merlin
- CHU de Quebec-Laval University Research Center, Neuroscience and Cancer Axes, Laboratory for Skin Cancer Research, 2705, Boulevard Laurier, Quebec (QC), Canada; Université Laval Cancer Research Center, Quebec (QC), Canada
| | - Girish M Shah
- CHU de Quebec-Laval University Research Center, Neuroscience and Cancer Axes, Laboratory for Skin Cancer Research, 2705, Boulevard Laurier, Quebec (QC), Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec (QC), Canada; Université Laval Cancer Research Center, Quebec (QC), Canada.
| |
Collapse
|
24
|
Katona L, Hartwich K, Tomioka R, Somogyi J, Roberts JDB, Wagner K, Joshi A, Klausberger T, Rockland KS, Somogyi P. Synaptic organisation and behaviour-dependent activity of mGluR8a-innervated GABAergic trilaminar cells projecting from the hippocampus to the subiculum. Brain Struct Funct 2020; 225:705-734. [PMID: 32016558 PMCID: PMC7046583 DOI: 10.1007/s00429-020-02029-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/16/2020] [Indexed: 02/07/2023]
Abstract
In the hippocampal CA1 area, the GABAergic trilaminar cells have their axon distributed locally in three layers and also innervate the subiculum. Trilaminar cells have a high level of somato-dendritic muscarinic M2 acetylcholine receptor, lack somatostatin expression and their presynaptic inputs are enriched in mGluR8a. But the origin of their inputs and their behaviour-dependent activity remain to be characterised. Here we demonstrate that (1) GABAergic neurons with the molecular features of trilaminar cells are present in CA1 and CA3 in both rats and mice. (2) Trilaminar cells receive mGluR8a-enriched GABAergic inputs, e.g. from the medial septum, which are probably susceptible to hetero-synaptic modulation of neurotransmitter release by group III mGluRs. (3) An electron microscopic analysis identifies trilaminar cell output synapses with specialised postsynaptic densities and a strong bias towards interneurons as targets, including parvalbumin-expressing cells in the CA1 area. (4) Recordings in freely moving rats revealed the network state-dependent segregation of trilaminar cell activity, with reduced firing during movement, but substantial increase in activity with prolonged burst firing (> 200 Hz) during slow wave sleep. We predict that the behaviour-dependent temporal dynamics of trilaminar cell firing are regulated by their specialised inhibitory inputs. Trilaminar cells might support glutamatergic principal cells by disinhibition and mediate the binding of neuronal assemblies between the hippocampus and the subiculum via the transient inhibition of local interneurons.
Collapse
Affiliation(s)
- Linda Katona
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| | - Katja Hartwich
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Ryohei Tomioka
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
- Laboratory for Cortical Organization and Systematics, RIKEN Brain Science Institute, Wako, Saitama, 351-0198, Japan
- Department of Morphological Neural Science, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Jozsef Somogyi
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - J David B Roberts
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Kristina Wagner
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Abhilasha Joshi
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
- Department of Physiology, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, USA
| | - Thomas Klausberger
- Center for Brain Research, Division of Cognitive Neurobiology, Medical University of Vienna, 1090, Vienna, Austria
| | - Kathleen S Rockland
- Laboratory for Cortical Organization and Systematics, RIKEN Brain Science Institute, Wako, Saitama, 351-0198, Japan
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 72 East Concord St., Boston, MA, 02118, USA
| | - Peter Somogyi
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
| |
Collapse
|
25
|
Dissociation of somatostatin and parvalbumin interneurons circuit dysfunctions underlying hippocampal theta and gamma oscillations impaired by amyloid β oligomers in vivo. Brain Struct Funct 2020; 225:935-954. [PMID: 32107637 PMCID: PMC7166204 DOI: 10.1007/s00429-020-02044-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 02/06/2020] [Indexed: 12/18/2022]
Abstract
Accumulation of amyloid β oligomers (AβO) in Alzheimer’s disease (AD) impairs hippocampal theta and gamma oscillations. These oscillations are important in memory functions and depend on distinct subtypes of hippocampal interneurons such as somatostatin-positive (SST) and parvalbumin-positive (PV) interneurons. Here, we investigated whether AβO causes dysfunctions in SST and PV interneurons by optogenetically manipulating them during theta and gamma oscillations in vivo in AβO-injected SST-Cre or PV-Cre mice. Hippocampal in vivo multi-electrode recordings revealed that optogenetic activation of channelrhodopsin-2 (ChR2)-expressing SST and PV interneurons in AβO-injected mice selectively restored AβO-induced reduction of the peak power of theta and gamma oscillations, respectively, and resynchronized CA1 pyramidal cell (PC) spikes. Moreover, SST and PV interneuron spike phases were resynchronized relative to theta and gamma oscillations, respectively. Whole-cell voltage-clamp recordings in CA1 PC in ex vivo hippocampal slices from AβO-injected mice revealed that optogenetic activation of SST and PV interneurons enhanced spontaneous inhibitory postsynaptic currents (IPSCs) selectively at theta and gamma frequencies, respectively. Furthermore, analyses of the stimulus–response curve, paired-pulse ratio, and short-term plasticity of SST and PV interneuron-evoked IPSCs ex vivo showed that AβO increased the initial GABA release probability to depress SST/PV interneuron’s inhibitory input to CA1 PC selectively at theta and gamma frequencies, respectively. Our results reveal frequency-specific and interneuron subtype-specific presynaptic dysfunctions of SST and PV interneurons’ input to CA1 PC as the synaptic mechanisms underlying AβO-induced impairments of hippocampal network oscillations and identify them as potential therapeutic targets for restoring hippocampal network oscillations in early AD.
Collapse
|
26
|
Blankvoort S, Descamps LAL, Kentros C. Enhancer-Driven Gene Expression (EDGE) enables the generation of cell type specific tools for the analysis of neural circuits. Neurosci Res 2020; 152:78-86. [PMID: 31958494 DOI: 10.1016/j.neures.2020.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 12/20/2022]
Abstract
As in all circuits, fully understanding how neural circuits operate requires the ability to specifically manipulate individual circuit elements, i.e. particular neuronal cell types. While recent years saw the development of molecular genetic tools allowing one to control and monitor neuronal activity, progress is limited by the ability to express such transgenes specifically enough. This goal is complicated by the fact that we are only beginning to understand how many cell types exist in the mammalian brain. Obtaining neuronal cell type-specific expression requires co-opting the genetic machinery which specifies their striking diversity, typically done by making transgenic animals using promoters expressing in neurons. However, while the vast majority of genes express in the brain, they almost always express in multiple cell types, meaning native promoters are not specific enough. We have recently taken a new approach to increase the specificity of transgene expression based upon identifying the distal cis-regulatory genomic elements (i.e. enhancers) uniquely active in a brain region and combining them with a heterologous minimal promoter. Termed Enhancer-Driven Gene Expression (EDGE), it allows for the generation of transgenic animals targeting the cell types of any brain region with far greater specificity than can be obtained with native promoters. Moreover, their small size allows for the generation of cell-specific viral vectors, conceivably enabling circuit-specific manipulations to any species.
Collapse
Affiliation(s)
- Stefan Blankvoort
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim, Norway.
| | - Lucie A L Descamps
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim, Norway
| | - Cliff Kentros
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim, Norway.
| |
Collapse
|
27
|
Swaminathan A, Wichert I, Schmitz D, Maier N. Involvement of Mossy Cells in Sharp Wave-Ripple Activity In Vitro. Cell Rep 2019; 23:2541-2549. [PMID: 29847786 DOI: 10.1016/j.celrep.2018.04.095] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/31/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022] Open
Abstract
The role of mossy cells (MCs) of the hippocampal dentate area has long remained mysterious. Recent research has begun to unveil their significance in spatial computation of the hippocampus. Here, we used an in vitro model of sharp wave-ripple complexes (SWRs), which contribute to hippocampal memory formation, to investigate MC involvement in this fundamental population activity. We find that a significant fraction of MCs (∼47%) is recruited into the active neuronal network during SWRs in the CA3 area. Moreover, MCs receive pronounced, ripple-coherent, excitatory and inhibitory synaptic input. Finally, we find evidence for SWR-related synaptic activity in granule cells that is mediated by MCs. Given the widespread connectivity of MCs within and between hippocampi, our data suggest a role for MCs as a hub functionally coupling the CA3 and the DG during ripple-associated computations.
Collapse
Affiliation(s)
- Aarti Swaminathan
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Cluster of Excellence NeuroCure, 10117 Berlin, Germany
| | - Ines Wichert
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany; Berlin Institute of Health, 10178 Berlin, Germany; Cluster of Excellence NeuroCure, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
| | - Nikolaus Maier
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany.
| |
Collapse
|
28
|
Cid E, de la Prida LM. Methods for single-cell recording and labeling in vivo. J Neurosci Methods 2019; 325:108354. [PMID: 31302156 DOI: 10.1016/j.jneumeth.2019.108354] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 07/07/2019] [Accepted: 07/07/2019] [Indexed: 01/29/2023]
Abstract
Targeting individual neurons in vivo is a key method to study the role of single cell types within local and brain-wide microcircuits. While novel technological developments now permit assessing activity from large number of cells simultaneously, there is currently no better solution than glass micropipettes to relate the physiology and morphology of single-cells. Sharp intracellular, juxtacellular, loose-patch and whole-cell approaches are some of the configurations used to record and label individual neurons. Here, we review procedures to establish successful electrophysiological recordings in vivo followed by appropriate labeling for post hoc morphological analysis. We provide operational recommendations for optimizing each configuration and a generic framework for functional, neurochemical and morphological identification of the different cell-types in a given region. Finally, we highlight emerging approaches that are challenging our current paradigms for single-cell recording and labeling in the living brain.
Collapse
Affiliation(s)
- Elena Cid
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid, 28002, Spain
| | | |
Collapse
|
29
|
Tzilivaki A, Kastellakis G, Poirazi P. Challenging the point neuron dogma: FS basket cells as 2-stage nonlinear integrators. Nat Commun 2019; 10:3664. [PMID: 31413258 PMCID: PMC6694133 DOI: 10.1038/s41467-019-11537-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 07/15/2019] [Indexed: 12/16/2022] Open
Abstract
Interneurons are critical for the proper functioning of neural circuits. While often morphologically complex, their dendrites have been ignored for decades, treating them as linear point neurons. Exciting new findings reveal complex, non-linear dendritic computations that call for a new theory of interneuron arithmetic. Using detailed biophysical models, we predict that dendrites of FS basket cells in both hippocampus and prefrontal cortex come in two flavors: supralinear, supporting local sodium spikes within large-volume branches and sublinear, in small-volume branches. Synaptic activation of varying sets of these dendrites leads to somatic firing variability that cannot be fully explained by the point neuron reduction. Instead, a 2-stage artificial neural network (ANN), with sub- and supralinear hidden nodes, captures most of the variance. Reduced neuronal circuit modeling suggest that this bi-modal, 2-stage integration in FS basket cells confers substantial resource savings in memory encoding as well as the linking of memories across time.
Collapse
Affiliation(s)
- Alexandra Tzilivaki
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
- Department of Biology, University of Crete, Heraklion, 70013, Greece
- Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, Charitéplatz 1, 10117, Berlin, Germany
| | - George Kastellakis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece.
| |
Collapse
|
30
|
Rock C, Zurita H, Lebby S, Wilson CJ, Apicella AJ. Cortical Circuits of Callosal GABAergic Neurons. Cereb Cortex 2019; 28:1154-1167. [PMID: 28174907 DOI: 10.1093/cercor/bhx025] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
Anatomical studies have shown that the majority of callosal axons are glutamatergic. However, a small proportion of callosal axons are also immunoreactive for glutamic acid decarboxylase, an enzyme required for gamma-aminobutyric acid (GABA) synthesis and a specific marker for GABAergic neurons. Here, we test the hypothesis that corticocortical parvalbumin-expressing (CC-Parv) neurons connect the two hemispheres of multiple cortical areas, project through the corpus callosum, and are a functional part of the local cortical circuit. Our investigation of this hypothesis takes advantage of viral tracing and optogenetics to determine the anatomical and electrophysiological properties of CC-Parv neurons of the mouse auditory, visual, and motor cortices. We found a direct inhibitory pathway made up of parvalbumin-expressing (Parv) neurons which connects corresponding cortical areas (CC-Parv neurons → contralateral cortex). Like other Parv cortical neurons, these neurons provide local inhibition onto nearby pyramidal neurons and receive thalamocortical input. These results demonstrate a previously unknown long-range inhibitory circuit arising from a genetically defined type of GABAergic neuron that is engaged in interhemispheric communication.
Collapse
Affiliation(s)
- Crystal Rock
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Hector Zurita
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Sharmon Lebby
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Charles J Wilson
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Alfonso Junior Apicella
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| |
Collapse
|
31
|
Gerbatin RR, Silva LFA, Hoffmann MS, Della-Pace ID, do Nascimento PS, Kegler A, de Zorzi VN, Cunha JM, Botelho P, Neto JBT, Furian AF, Oliveira MS, Fighera MR, Royes LFF. Delayed creatine supplementation counteracts reduction of GABAergic function and protects against seizures susceptibility after traumatic brain injury in rats. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:328-338. [PMID: 30742861 DOI: 10.1016/j.pnpbp.2019.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/23/2019] [Accepted: 02/07/2019] [Indexed: 12/28/2022]
Abstract
Traumatic brain injury (TBI) is a devastating disease frequently followed by behavioral disabilities including post-traumatic epilepsy (PTE). Although reasonable progress in understanding its pathophysiology has been made, treatment of PTE is still limited. Several studies have shown the neuroprotective effect of creatine in different models of brain pathology, but its effects on PTE is not elucidated. Thus, we decided to investigate the impact of delayed and chronic creatine supplementation on susceptibility to epileptic seizures evoked by pentylenetetrazol (PTZ) after TBI. Our experimental data revealed that 4 weeks of creatine supplementation (300 mg/kg, p.o.) initiated 1 week after fluid percussion injury (FPI) notably increased the latency to first myoclonic and tonic-clonic seizures, decreased the time spent in tonic-clonic seizure, seizure intensity, epileptiform discharges and spindle oscillations induced by a sub-convulsant dose of PTZ (35 mg/kg, i.p.). Interestingly, this protective effect persists for 1 week even when creatine supplementation is discontinued. The anticonvulsant effect of creatine was associated with its ability to reduce cell loss including the number of parvalbumin positive (PARV+) cells in CA3 region of the hippocampus. Furthermore, creatine supplementation also protected against the reduction of GAD67 levels, GAD activity and specific [3H]flunitrazepam binding in the hippocampus. These findings showed that chronic creatine supplementation may play a neuroprotective role on brain excitability by controlling the GABAergic function after TBI, providing a possible new strategy for the treatment of PTE.
Collapse
Affiliation(s)
- Rogerio R Gerbatin
- Laboratório de Bioquímica do Exercício, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Luiz Fernando Almeida Silva
- Laboratório de Bioquímica do Exercício, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Maurício S Hoffmann
- Departamento de Neuropsiquiatria, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Iuri D Della-Pace
- Laboratório de Bioquímica do Exercício, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Patricia Severo do Nascimento
- Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Aline Kegler
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Viviane Nogueira de Zorzi
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Jane Marçal Cunha
- ratório de Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federaldo Pará, PA, Brazil
| | - Priscilla Botelho
- ratório de Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federaldo Pará, PA, Brazil
| | - João Bento Torres Neto
- ratório de Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federaldo Pará, PA, Brazil
| | - Ana Flavia Furian
- Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Mauro Schneider Oliveira
- Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michele R Fighera
- Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Laboratório de Bioquímica do Exercício, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Luiz Fernando Freire Royes
- Programa de Pós-Graduação em Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Laboratório de Bioquímica do Exercício, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
| |
Collapse
|
32
|
Świetlik D, Białowąs J, Moryś J, Klejbor I, Kusiak A. Computer Modeling of Alzheimer's Disease-Simulations of Synaptic Plasticity and Memory in the CA3-CA1 Hippocampal Formation Microcircuit. Molecules 2019; 24:E1909. [PMID: 31108977 PMCID: PMC6571632 DOI: 10.3390/molecules24101909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/12/2019] [Accepted: 05/16/2019] [Indexed: 12/19/2022] Open
Abstract
This paper aims to present computer modeling of synaptic plasticity and memory in the CA3-CA1 hippocampal formation microcircuit. The computer simulations showed a comparison of a pathological model in which Alzheimer's disease (AD) was simulated by synaptic degradation in the hippocampus and control model (healthy) of CA3-CA1 networks with modification of weights for the memory. There were statistically higher spike values of both CA1 and CA3 pyramidal cells in the control model than in the pathological model (p = 0.0042 for CA1 and p = 0.0033 for CA3). A similar outcome was achieved for frequency (p = 0.0002 for CA1 and p = 0.0001 for CA3). The entropy of pyramidal cells of the healthy CA3 network seemed to be significantly higher than that of AD (p = 0.0304). We need to study a lot of physiological parameters and their combinations of the CA3-CA1 hippocampal formation microcircuit to understand AD. High statistically correlations were obtained between memory, spikes and synaptic deletion in both CA1 and CA3 cells.
Collapse
Affiliation(s)
- Dariusz Świetlik
- Intrafaculty College of Medical Informatics and Biostatistics, Medical University of Gdańsk, 1 Debinki St., 80-211 Gdańsk, Poland.
| | - Jacek Białowąs
- Department of Anatomy and Neurobiology, Medical University of Gdańsk, 1 Debinki St., 80-211 Gdańsk, Poland.
| | - Janusz Moryś
- Department of Anatomy and Neurobiology, Medical University of Gdańsk, 1 Debinki St., 80-211 Gdańsk, Poland.
| | - Ilona Klejbor
- Department of Anatomy and Neurobiology, Medical University of Gdańsk, 1 Debinki St., 80-211 Gdańsk, Poland.
| | - Aida Kusiak
- Department of Periodontology and Oral Mucosa Diseases, Medical University of Gdańsk, 1a Debowa St., 80-204 Gdańsk, Poland.
| |
Collapse
|
33
|
Kassi AAY, Mahavadi AK, Clavijo A, Caliz D, Lee SW, Ahmed AI, Yokobori S, Hu Z, Spurlock MS, Wasserman JM, Rivera KN, Nodal S, Powell HR, Di L, Torres R, Leung LY, Rubiano AM, Bullock RM, Gajavelli S. Enduring Neuroprotective Effect of Subacute Neural Stem Cell Transplantation After Penetrating TBI. Front Neurol 2019; 9:1097. [PMID: 30719019 PMCID: PMC6348935 DOI: 10.3389/fneur.2018.01097] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 12/03/2018] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is the largest cause of death and disability of persons under 45 years old, worldwide. Independent of the distribution, outcomes such as disability are associated with huge societal costs. The heterogeneity of TBI and its complicated biological response have helped clarify the limitations of current pharmacological approaches to TBI management. Five decades of effort have made some strides in reducing TBI mortality but little progress has been made to mitigate TBI-induced disability. Lessons learned from the failure of numerous randomized clinical trials and the inability to scale up results from single center clinical trials with neuroprotective agents led to the formation of organizations such as the Neurological Emergencies Treatment Trials (NETT) Network, and international collaborative comparative effectiveness research (CER) to re-orient TBI clinical research. With initiatives such as TRACK-TBI, generating rich and comprehensive human datasets with demographic, clinical, genomic, proteomic, imaging, and detailed outcome data across multiple time points has become the focus of the field in the United States (US). In addition, government institutions such as the US Department of Defense are investing in groups such as Operation Brain Trauma Therapy (OBTT), a multicenter, pre-clinical drug-screening consortium to address the barriers in translation. The consensus from such efforts including “The Lancet Neurology Commission” and current literature is that unmitigated cell death processes, incomplete debris clearance, aberrant neurotoxic immune, and glia cell response induce progressive tissue loss and spatiotemporal magnification of primary TBI. Our analysis suggests that the focus of neuroprotection research needs to shift from protecting dying and injured neurons at acute time points to modulating the aberrant glial response in sub-acute and chronic time points. One unexpected agent with neuroprotective properties that shows promise is transplantation of neural stem cells. In this review we present (i) a short survey of TBI epidemiology and summary of current care, (ii) findings of past neuroprotective clinical trials and possible reasons for failure based upon insights from human and preclinical TBI pathophysiology studies, including our group's inflammation-centered approach, (iii) the unmet need of TBI and unproven treatments and lastly, (iv) present evidence to support the rationale for sub-acute neural stem cell therapy to mediate enduring neuroprotection.
Collapse
Affiliation(s)
- Anelia A Y Kassi
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Anil K Mahavadi
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Angelica Clavijo
- Neurosurgery Service, INUB-MEDITECH Research Group, El Bosque University, Bogotá, CO, United States
| | - Daniela Caliz
- Neurosurgery Service, INUB-MEDITECH Research Group, El Bosque University, Bogotá, CO, United States
| | - Stephanie W Lee
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Aminul I Ahmed
- Wessex Neurological Centre, University Hospitals Southampton, Southampton, United Kingdom
| | - Shoji Yokobori
- Department of Emergency and Critical Care Medicine, Nippon Medical School, Tokyo, Japan
| | - Zhen Hu
- Department of Neurosurgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Markus S Spurlock
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Joseph M Wasserman
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Karla N Rivera
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Samuel Nodal
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Henry R Powell
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Long Di
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Rolando Torres
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Lai Yee Leung
- Branch of Brain Trauma Neuroprotection and Neurorestoration, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States.,Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Andres Mariano Rubiano
- Neurosurgery Service, INUB-MEDITECH Research Group, El Bosque University, Bogotá, CO, United States
| | - Ross M Bullock
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Shyam Gajavelli
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| |
Collapse
|
34
|
Booker SA, Vida I. Morphological diversity and connectivity of hippocampal interneurons. Cell Tissue Res 2018; 373:619-641. [PMID: 30084021 PMCID: PMC6132631 DOI: 10.1007/s00441-018-2882-2] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/03/2018] [Indexed: 12/21/2022]
Abstract
The mammalian forebrain is constructed from ensembles of neurons that form local microcircuits giving rise to the exquisite cognitive tasks the mammalian brain can perform. Hippocampal neuronal circuits comprise populations of relatively homogenous excitatory neurons, principal cells and exceedingly heterogeneous inhibitory neurons, the interneurons. Interneurons release GABA from their axon terminals and are capable of controlling excitability in every cellular compartment of principal cells and interneurons alike; thus, they provide a brake on excess activity, control the timing of neuronal discharge and provide modulation of synaptic transmission. The dendritic and axonal morphology of interneurons, as well as their afferent and efferent connections within hippocampal circuits, is central to their ability to differentially control excitability, in a cell-type- and compartment-specific manner. This review aims to provide an up-to-date compendium of described hippocampal interneuron subtypes, with respect to their morphology, connectivity, neurochemistry and physiology, a full understanding of which will in time help to explain the rich diversity of neuronal function.
Collapse
Affiliation(s)
- Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK.
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD, UK.
| | - Imre Vida
- Institute for Integrative Neuroanatomy, Charité - Universitätmedizin Berlin, Berlin, Germany.
| |
Collapse
|
35
|
Hainmueller T, Bartos M. Parallel emergence of stable and dynamic memory engrams in the hippocampus. Nature 2018; 558:292-296. [PMID: 29875406 DOI: 10.1038/s41586-018-0191-2] [Citation(s) in RCA: 211] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/30/2018] [Indexed: 12/31/2022]
Abstract
During our daily life, we depend on memories of past experiences to plan future behaviour. These memories are represented by the activity of specific neuronal groups or 'engrams'1,2. Neuronal engrams are assembled during learning by synaptic modification, and engram reactivation represents the memorized experience 1 . Engrams of conscious memories are initially stored in the hippocampus for several days and then transferred to cortical areas 2 . In the dentate gyrus of the hippocampus, granule cells transform rich inputs from the entorhinal cortex into a sparse output, which is forwarded to the highly interconnected pyramidal cell network in hippocampal area CA3 3 . This process is thought to support pattern separation 4 (but see refs. 5,6). CA3 pyramidal neurons project to CA1, the hippocampal output region. Consistent with the idea of transient memory storage in the hippocampus, engrams in CA1 and CA2 do not stabilize over time7-10. Nevertheless, reactivation of engrams in the dentate gyrus can induce recall of artificial memories even after weeks 2 . Reconciliation of this apparent paradox will require recordings from dentate gyrus granule cells throughout learning, which has so far not been performed for more than a single day6,11,12. Here, we use chronic two-photon calcium imaging in head-fixed mice performing a multiple-day spatial memory task in a virtual environment to record neuronal activity in all major hippocampal subfields. Whereas pyramidal neurons in CA1-CA3 show precise and highly context-specific, but continuously changing, representations of the learned spatial sceneries in our behavioural paradigm, granule cells in the dentate gyrus have a spatial code that is stable over many days, with low place- or context-specificity. Our results suggest that synaptic weights along the hippocampal trisynaptic loop are constantly reassigned to support the formation of dynamic representations in downstream hippocampal areas based on a stable code provided by the dentate gyrus.
Collapse
Affiliation(s)
- Thomas Hainmueller
- Institute for Physiology I, Systemic and Cellular Neurophysiology, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Marlene Bartos
- Institute for Physiology I, Systemic and Cellular Neurophysiology, University of Freiburg, Freiburg, Germany.
| |
Collapse
|
36
|
Zurita H, Feyen PLC, Apicella AJ. Layer 5 Callosal Parvalbumin-Expressing Neurons: A Distinct Functional Group of GABAergic Neurons. Front Cell Neurosci 2018; 12:53. [PMID: 29559891 PMCID: PMC5845545 DOI: 10.3389/fncel.2018.00053] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 02/15/2018] [Indexed: 12/22/2022] Open
Abstract
Previous studies have shown that parvalbumin-expressing neurons (CC-Parv neurons) connect the two hemispheres of motor and sensory areas via the corpus callosum, and are a functional part of the cortical circuit. Here we test the hypothesis that layer 5 CC-Parv neurons possess anatomical and molecular mechanisms which dampen excitability and modulate the gating of interhemispheric inhibition. In order to investigate this hypothesis we use viral tracing to determine the anatomical and electrophysiological properties of layer 5 CC-Parv and parvalbumin-expressing (Parv) neurons of the mouse auditory cortex (AC). Here we show that layer 5 CC-Parv neurons had larger dendritic fields characterized by longer dendrites that branched farther from the soma, whereas layer 5 Parv neurons had smaller dendritic fields characterized by shorter dendrites that branched nearer to the soma. The layer 5 CC-Parv neurons are characterized by delayed action potential (AP) responses to threshold currents, lower firing rates, and lower instantaneous frequencies compared to the layer 5 Parv neurons. Kv1.1 containing K+ channels are the main source of the AP repolarization of the layer 5 CC-Parv and have a major role in determining both the spike delayed response, firing rate and instantaneous frequency of these neurons.
Collapse
Affiliation(s)
- Hector Zurita
- Department of Biology, Neurosciences Institute, University of Texas, San Antonio, San Antonio, TX, United States
| | - Paul L C Feyen
- Department of Biology, Neurosciences Institute, University of Texas, San Antonio, San Antonio, TX, United States
| | - Alfonso Junior Apicella
- Department of Biology, Neurosciences Institute, University of Texas, San Antonio, San Antonio, TX, United States
| |
Collapse
|
37
|
Unal G, Crump MG, Viney TJ, Éltes T, Katona L, Klausberger T, Somogyi P. Spatio-temporal specialization of GABAergic septo-hippocampal neurons for rhythmic network activity. Brain Struct Funct 2018; 223:2409-2432. [PMID: 29500537 PMCID: PMC5968071 DOI: 10.1007/s00429-018-1626-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/10/2018] [Indexed: 01/06/2023]
Abstract
Medial septal GABAergic neurons of the basal forebrain innervate the hippocampus and related cortical areas, contributing to the coordination of network activity, such as theta oscillations and sharp wave-ripple events, via a preferential innervation of GABAergic interneurons. Individual medial septal neurons display diverse activity patterns, which may be related to their termination in different cortical areas and/or to the different types of innervated interneurons. To test these hypotheses, we extracellularly recorded and juxtacellularly labeled single medial septal neurons in anesthetized rats in vivo during hippocampal theta and ripple oscillations, traced their axons to distant cortical target areas, and analyzed their postsynaptic interneurons. Medial septal GABAergic neurons exhibiting different hippocampal theta phase preferences and/or sharp wave-ripple related activity terminated in restricted hippocampal regions, and selectively targeted a limited number of interneuron types, as established on the basis of molecular markers. We demonstrate the preferential innervation of bistratified cells in CA1 and of basket cells in CA3 by individual axons. One group of septal neurons was suppressed during sharp wave-ripples, maintained their firing rate across theta and non-theta network states and mainly fired along the descending phase of CA1 theta oscillations. In contrast, neurons that were active during sharp wave-ripples increased their firing significantly during "theta" compared to "non-theta" states, with most firing during the ascending phase of theta oscillations. These results demonstrate that specialized septal GABAergic neurons contribute to the coordination of network activity through parallel, target area- and cell type-selective projections to the hippocampus.
Collapse
Affiliation(s)
- Gunes Unal
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK.
- Department of Psychology, Bogazici University, 34342, Istanbul, Turkey.
| | - Michael G Crump
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK
| | - Tim J Viney
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK
| | - Tímea Éltes
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary
| | - Linda Katona
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK
| | - Thomas Klausberger
- Center for Brain Research, Medical University of Vienna, 1090, Vienna, Austria
| | - Peter Somogyi
- Department of Pharmacology, Mansfield Rd, University of Oxford, Oxford, OX1 3QT, UK.
- Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083, Budapest, Hungary.
| |
Collapse
|
38
|
Zhang L, Hernández VS, Swinny JD, Verma AK, Giesecke T, Emery AC, Mutig K, Garcia-Segura LM, Eiden LE. A GABAergic cell type in the lateral habenula links hypothalamic homeostatic and midbrain motivation circuits with sex steroid signaling. Transl Psychiatry 2018; 8:50. [PMID: 29479060 PMCID: PMC5865187 DOI: 10.1038/s41398-018-0099-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 01/08/2018] [Indexed: 12/16/2022] Open
Abstract
The lateral habenula (LHb) has a key role in integrating a variety of neural circuits associated with reward and aversive behaviors. There is limited information about how the different cell types and neuronal circuits within the LHb coordinate physiological and motivational states. Here, we report a cell type in the medial division of the LHb (LHbM) in male rats that is distinguished by: (1) a molecular signature for GABAergic neurotransmission (Slc32a1/VGAT) and estrogen receptor (Esr1/ERα) expression, at both mRNA and protein levels, as well as the mRNA for vesicular glutamate transporter Slc17a6/VGLUT2, which we term the GABAergic estrogen-receptive neuron (GERN); (2) its axonal projection patterns, identified by in vivo juxtacellular labeling, to both local LHb and to midbrain modulatory systems; and (3) its somatic expression of receptors for vasopressin, serotonin and dopamine, and mRNA for orexin receptor 2. This cell type is anatomically located to receive afferents from midbrain reward (dopamine and serotonin) and hypothalamic water and energy homeostasis (vasopressin and orexin) circuits. These afferents shared the expression of estrogen synthase (aromatase) and VGLUT2, both in their somata and axon terminals. We demonstrate dynamic changes in LHbM VGAT+ cell density, dependent upon gonadal functional status, that closely correlate with motivational behavior in response to predator and forced swim stressors. The findings suggest that the homeostasis and reward-related glutamatergic convergent projecting pathways to LHbMC employ a localized neurosteroid signaling mechanism via axonal expression of aromatase, to act as a switch for GERN excitation/inhibition output prevalence, influencing depressive or motivated behavior.
Collapse
Affiliation(s)
- Limei Zhang
- Departmento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico. .,Section on Molecular Neuroscience, National Institute of Mental Health (NIH), Bethesda, USA.
| | - Vito S. Hernández
- 0000 0001 2159 0001grid.9486.3Departmento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jerome D. Swinny
- 0000 0001 0728 6636grid.4701.2Institute for Biomedical and Biomolecular Sciences, School of Pharmacy & Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Anil K. Verma
- 0000 0001 2159 0001grid.9486.3Departmento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Torsten Giesecke
- 0000 0001 2218 4662grid.6363.0Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Andrew C. Emery
- 0000 0004 0464 0574grid.416868.5Section on Molecular Neuroscience, National Institute of Mental Health (NIH), Bethesda, USA
| | - Kerim Mutig
- 0000 0001 2218 4662grid.6363.0Department of Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Luis M. Garcia-Segura
- 0000 0001 2177 5516grid.419043.bInstituto Cajal, C.S.I.C., Madrid, Spain ,0000 0000 9314 1427grid.413448.eCIBERFES, Instituto de Salud Carlos III, Madrid, Spain
| | - Lee E. Eiden
- 0000 0004 0464 0574grid.416868.5Section on Molecular Neuroscience, National Institute of Mental Health (NIH), Bethesda, USA
| |
Collapse
|
39
|
Hippocampal Ripple Oscillations and Inhibition-First Network Models: Frequency Dynamics and Response to GABA Modulators. J Neurosci 2018; 38:3124-3146. [PMID: 29453207 DOI: 10.1523/jneurosci.0188-17.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 01/25/2018] [Accepted: 02/05/2018] [Indexed: 11/21/2022] Open
Abstract
Hippocampal ripples are involved in memory consolidation, but the mechanisms underlying their generation remain unclear. Models relying on interneuron networks in the CA1 region disagree on the predominant source of excitation to interneurons: either "direct," via the Schaffer collaterals that provide feedforward input from CA3 to CA1, or "indirect," via the local pyramidal cells in CA1, which are embedded in a recurrent excitatory-inhibitory network. Here, we used physiologically constrained computational models of basket-cell networks to investigate how they respond to different conditions of transient, noisy excitation. We found that direct excitation of interneurons could evoke ripples (140-220 Hz) that exhibited intraripple frequency accommodation and were frequency-insensitive to GABA modulators, as previously shown in in vitro experiments. In addition, the indirect excitation of the basket-cell network enabled the expression of intraripple frequency accommodation in the fast-gamma range (90-140 Hz), as in vivo In our model, intraripple frequency accommodation results from a hysteresis phenomenon in which the frequency responds differentially to the rising and descending phases of the transient excitation. Such a phenomenon predicts a maximum oscillation frequency occurring several milliseconds before the peak of excitation. We confirmed this prediction for ripples in brain slices from male mice. These results suggest that ripple and fast-gamma episodes are produced by the same interneuron network that is recruited via different excitatory input pathways, which could be supported by the previously reported intralaminar connectivity bias between basket cells and functionally distinct subpopulations of pyramidal cells in CA1. Together, our findings unify competing inhibition-first models of rhythm generation in the hippocampus.SIGNIFICANCE STATEMENT The hippocampus is a part of the brain of humans and other mammals that is critical for the acquisition and consolidation of memories. During deep sleep and resting periods, the hippocampus generates high-frequency (∼200 Hz) oscillations called ripples, which are important for memory consolidation. The mechanisms underlying ripple generation are not well understood. A prominent hypothesis holds that the ripples are generated by local recurrent networks of inhibitory neurons. Using computational models and experiments in brain slices from rodents, we show that the dynamics of interneuron networks clarify several previously unexplained characteristics of ripple oscillations, which advances our understanding of hippocampus-dependent memory consolidation.
Collapse
|
40
|
Joshi A, Salib M, Viney TJ, Dupret D, Somogyi P. Behavior-Dependent Activity and Synaptic Organization of Septo-hippocampal GABAergic Neurons Selectively Targeting the Hippocampal CA3 Area. Neuron 2017; 96:1342-1357.e5. [PMID: 29198757 PMCID: PMC5746169 DOI: 10.1016/j.neuron.2017.10.033] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/23/2017] [Accepted: 10/25/2017] [Indexed: 12/12/2022]
Abstract
Rhythmic medial septal (MS) GABAergic input coordinates cortical theta oscillations. However, the rules of innervation of cortical cells and regions by diverse septal neurons are unknown. We report a specialized population of septal GABAergic neurons, the Teevra cells, selectively innervating the hippocampal CA3 area bypassing CA1, CA2, and the dentate gyrus. Parvalbumin-immunopositive Teevra cells show the highest rhythmicity among MS neurons and fire with short burst duration (median, 38 ms) preferentially at the trough of both CA1 theta and slow irregular oscillations, coincident with highest hippocampal excitability. Teevra cells synaptically target GABAergic axo-axonic and some CCK interneurons in restricted septo-temporal CA3 segments. The rhythmicity of their firing decreases from septal to temporal termination of individual axons. We hypothesize that Teevra neurons coordinate oscillatory activity across the septo-temporal axis, phasing the firing of specific CA3 interneurons, thereby contributing to the selection of pyramidal cell assemblies at the theta trough via disinhibition. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Abhilasha Joshi
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK; MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, UK.
| | - Minas Salib
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Tim James Viney
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - David Dupret
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK; MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, UK
| | - Peter Somogyi
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK; Center for Brain Research, Medical University of Vienna, Vienna 1090, Austria.
| |
Collapse
|
41
|
Spatial Structure of Synchronized Inhibition in the Olfactory Bulb. J Neurosci 2017; 37:10468-10480. [PMID: 28947574 DOI: 10.1523/jneurosci.1004-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/22/2017] [Accepted: 09/14/2017] [Indexed: 11/21/2022] Open
Abstract
Olfactory sensory input is detected by receptor neurons in the nose, which then send information to the olfactory bulb (OB), the first brain region for processing olfactory information. Within the OB, many local circuit interneurons, including axonless granule cells, function to facilitate fine odor discrimination. How interneurons interact with principal cells to affect bulbar processing is not known, but the mechanism is likely to be different from that in sensory cortical regions because the OB lacks an obvious topographical organization. Neighboring glomerular columns, representing inputs from different receptor neuron subtypes, typically have different odor tuning. Determining the spatial scale over which interneurons such as granule cells can affect principal cells is a critical step toward understanding how the OB operates. We addressed this question by assaying inhibitory synchrony using intracellular recordings from pairs of principal cells with different intersomatic spacing. We found, in acute rat OB slices from both sexes, that inhibitory synchrony is evident in the spontaneous synaptic input in mitral cells (MCs) separated up to 220 μm (300 μm with elevated K+). At all intersomatic spacing assayed, inhibitory synchrony was dependent on Na+ channels, suggesting that action potentials in granule cells function to coordinate GABA release at relatively distant dendrodendritic synapses formed throughout the dendritic arbor. Our results suggest that individual granule cells are able to influence relatively large groups of MCs and tufted cells belonging to clusters of at least 15 glomerular modules, providing a potential mechanism to integrate signals reflecting a wide variety of odorants.SIGNIFICANCE STATEMENT Inhibitory circuits in the olfactory bulb (OB) play a major role in odor processing, especially during fine odor discrimination. However, how inhibitory networks enhance olfactory function, and over what spatial scale they operate, is not known. Interneurons are potentially able to function on both a highly localized, synapse-specific level and on a larger, spatial scale that encompasses many different glomerular channels. Although recent indirect evidence has suggested a relatively localized functional role for most inhibition in the OB, in the present study, we used paired intracellular recordings to demonstrate directly that inhibitory local circuits operate over large spatial scales by using fast action potentials to link GABA release at many different synaptic contacts formed with principal cells.
Collapse
|
42
|
Katona L, Micklem B, Borhegyi Z, Swiejkowski DA, Valenti O, Viney TJ, Kotzadimitriou D, Klausberger T, Somogyi P. Behavior-dependent activity patterns of GABAergic long-range projecting neurons in the rat hippocampus. Hippocampus 2017; 27:359-377. [PMID: 27997999 PMCID: PMC5363363 DOI: 10.1002/hipo.22696] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2016] [Indexed: 11/10/2022]
Abstract
Long-range glutamatergic and GABAergic projections participate in temporal coordination of neuronal activity in distributed cortical areas. In the hippocampus, GABAergic neurons project to the medial septum and retrohippocampal areas. Many GABAergic projection cells express somatostatin (SOM+) and, together with locally terminating SOM+ bistratified and O-LM cells, contribute to dendritic inhibition of pyramidal cells. We tested the hypothesis that diversity in SOM+ cells reflects temporal specialization during behavior using extracellular single cell recording and juxtacellular neurobiotin-labeling in freely moving rats. We have demonstrated that rare GABAergic projection neurons discharge rhythmically and are remarkably diverse. During sharp wave-ripples, most projection cells, including a novel SOM+ GABAergic back-projecting cell, increased their activity similar to bistratified cells, but unlike O-LM cells. During movement, most projection cells discharged along the descending slope of theta cycles, but some fired at the trough jointly with bistratified and O-LM cells. The specialization of hippocampal SOM+ projection neurons complements the action of local interneurons in differentially phasing inputs from the CA3 area to CA1 pyramidal cell dendrites during sleep and wakefulness. Our observations suggest that GABAergic projection cells mediate the behavior- and network state-dependent binding of neuronal assemblies amongst functionally-related brain regions by transmitting local rhythmic entrainment of neurons in CA1 to neuronal populations in other areas. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Linda Katona
- Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3QTUK
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- MRC Brain Network Dynamics Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
| | - Ben Micklem
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- MRC Brain Network Dynamics Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
| | - Zsolt Borhegyi
- Center for Brain Research, Medical University of ViennaViennaA‐1090Austria
- Department of BiochemistryEötvös Loránd UniversityBudapest1117Hungary
| | - Daniel A. Swiejkowski
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
| | - Ornella Valenti
- Center for Brain Research, Medical University of ViennaViennaA‐1090Austria
- Department of Neurophysiology and NeuropharmacologyCenter for Physiology and Pharmacology, Medical University of ViennaVienna1090Austria
| | - Tim J. Viney
- Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3QTUK
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- MRC Brain Network Dynamics Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
| | - Dimitrios Kotzadimitriou
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
| | - Thomas Klausberger
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- Center for Brain Research, Medical University of ViennaViennaA‐1090Austria
| | - Peter Somogyi
- Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3QTUK
- MRC Anatomical Neuropharmacology Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- MRC Brain Network Dynamics Unit, Department of PharmacologyUniversity of OxfordMansfield RoadOxfordOX1 3THUK
- Center for Brain Research, Medical University of ViennaViennaA‐1090Austria
| |
Collapse
|
43
|
Nasrallah K, Piskorowski RA, Chevaleyre V. Bi-directional interplay between proximal and distal inputs to CA2 pyramidal neurons. Neurobiol Learn Mem 2017; 138:173-181. [DOI: 10.1016/j.nlm.2016.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/22/2016] [Accepted: 06/25/2016] [Indexed: 10/21/2022]
|
44
|
Veres JM, Nagy GA, Hájos N. Perisomatic GABAergic synapses of basket cells effectively control principal neuron activity in amygdala networks. eLife 2017; 6. [PMID: 28060701 PMCID: PMC5218536 DOI: 10.7554/elife.20721] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/16/2016] [Indexed: 12/17/2022] Open
Abstract
Efficient control of principal neuron firing by basket cells is critical for information processing in cortical microcircuits, however, the relative contribution of their perisomatic and dendritic synapses to spike inhibition is still unknown. Using in vitro electrophysiological paired recordings we reveal that in the mouse basal amygdala cholecystokinin- and parvalbumin-containing basket cells provide equally potent control of principal neuron spiking. We performed pharmacological manipulations, light and electron microscopic investigations to show that, although basket cells innervate the entire somato-denditic membrane surface of principal neurons, the spike controlling effect is achieved primarily via the minority of synapses targeting the perisomatic region. As the innervation patterns of individual basket cells on their different postsynaptic partners show high variability, the impact of inhibitory control accomplished by single basket cells is also variable. Our results show that both basket cell types can powerfully regulate the activity in amygdala networks predominantly via their perisomatic synapses. DOI:http://dx.doi.org/10.7554/eLife.20721.001
Collapse
Affiliation(s)
- Judit M Veres
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Gergő A Nagy
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Norbert Hájos
- 'Lendület' Laboratory of Network Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| |
Collapse
|
45
|
Zaletel I, Filipović D, Puškaš N. Chronic stress, hippocampus and parvalbumin-positive interneurons: what do we know so far? Rev Neurosci 2016; 27:397-409. [DOI: 10.1515/revneuro-2015-0042] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/26/2015] [Indexed: 02/02/2023]
Abstract
AbstractThe hippocampus is a brain structure involved in the regulation of hypothalamic-pituitary-adrenal (HPA) axis and stress response. It plays an important role in the formation of declarative, spatial and contextual memory, as well as in the processing of emotional information. As a part of the limbic system, it is a very susceptible structure towards the effects of various stressors. The molecular mechanisms of structural and functional alternations that occur in the hippocampus under chronic stress imply an increased level of circulating glucocorticoids (GCs), which is an HPA axis response to stress. Certain data show that changes induced by chronic stress may be independent from the GCs levels, opening the possibility of existence of other poorly explored mechanisms and pathways through which stressors act. The hippocampal GABAergic parvalbumin-positive (PV+) interneurons represent an especially vulnerable population of neurons in chronic stress, which may be of key importance in the development of mood disorders. However, cellular and molecular hippocampal changes that arise as a consequence of chronic stress still represent a large and unexplored area. This review discusses the current knowledge about the PV+ interneurons of the hippocampus and the influence of chronic stress on this intriguing population of neurons.
Collapse
Affiliation(s)
- Ivan Zaletel
- 1Institute of Histology and Embryology “Aleksandar Đ. Kostić”, School of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | | | | |
Collapse
|
46
|
Abstract
PURPOSE OF REVIEW We review our current understanding of abnormal γ band oscillations in schizophrenia, their association with symptoms and the underlying cortical circuit abnormality, with a particular focus on the role of fast-spiking parvalbumin gamma-aminobutyric acid (GABA) neurons in the disease state. RECENT FINDINGS Clinical electrophysiological studies of schizophrenia patients and pharmacological models of the disorder show an increase in spontaneous γ band activity (not stimulus-evoked) measures. These findings provide a crucial link between preclinical and clinical work examining the role of γ band activity in schizophrenia. MRI-based experiments measuring cortical GABA provides evidence supporting impaired GABAergic neurotransmission in schizophrenia patients, which is correlated with γ band activity level. Several studies suggest that stimulation of the cortical circuitry, directly or via subcortical structures, has the potential to modulate cortical γ activity, and improve cognitive function. SUMMARY Abnormal γ band activity is observed in patients with schizophrenia and disease models in animals, and is suggested to underlie the psychosis and cognitive/perceptual deficits. Convergent evidence from both clinical and preclinical studies suggest the central factor in γ band abnormalities is impaired GABAergic neurotransmission, particularly in a subclass of neurons which express parvalbumin. Rescue of γ band abnormalities presents an intriguing option for therapeutic intervention.
Collapse
|
47
|
Zhang L, Hernández VS, Vázquez-Juárez E, Chay FK, Barrio RA. Thirst Is Associated with Suppression of Habenula Output and Active Stress Coping: Is there a Role for a Non-canonical Vasopressin-Glutamate Pathway? Front Neural Circuits 2016; 10:13. [PMID: 27065810 PMCID: PMC4814529 DOI: 10.3389/fncir.2016.00013] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/29/2016] [Indexed: 12/12/2022] Open
Abstract
Water-homeostasis is a fundamental physiological process for terrestrial life. In vertebrates, thirst drives water intake, but the neuronal circuits that connect the physiology of water regulation with emotional context are poorly understood. Vasopressin (VP) is a prominent messenger in this circuit, as well as L-glutamate. We have investigated the role of a VP circuit and interaction between thirst and motivational behaviors evoked by life-threatening stimuli in rats. We demonstrate a direct pathway from hypothalamic paraventricular VP-expressing, glutamatergic magnocellular neurons to the medial division of lateral habenula (LHbM), a region containing GABAergic neurons. In vivo recording and juxtacellular labeling revealed that GABAergic neurons in the LHbM had locally branching axons, and received VP-positive axon terminal contacts on their dendrites. Water deprivation significantly reduced freezing and immobility behaviors evoked by innate fear and behavioral despair, respectively, accompanied by decreased Fos expression in the lateral habenula. Our results reveal a novel VP-expressing hypothalamus to the LHbM circuit that is likely to evoke GABA-mediated inhibition in the LHbM, which promotes escape behavior during stress coping.
Collapse
Affiliation(s)
- Limei Zhang
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Ciudad de México, Mexico
| | - Vito S Hernández
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Ciudad de México, Mexico
| | - Erika Vázquez-Juárez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Ciudad de México, Mexico
| | - Freya K Chay
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Ciudad de México, Mexico
| | - Rafael A Barrio
- Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México Ciudad de México, Mexico
| |
Collapse
|
48
|
Hernández VS, Vázquez-Juárez E, Márquez MM, Jáuregui-Huerta F, Barrio RA, Zhang L. Extra-neurohypophyseal axonal projections from individual vasopressin-containing magnocellular neurons in rat hypothalamus. Front Neuroanat 2015; 9:130. [PMID: 26500509 PMCID: PMC4593857 DOI: 10.3389/fnana.2015.00130] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/18/2015] [Indexed: 01/19/2023] Open
Abstract
Conventional neuroanatomical, immunohistochemical techniques, and electrophysiological recording, as well as in vitro labeling methods may fail to detect long range extra-neurohypophyseal-projecting axons from vasopressin (AVP)-containing magnocellular neurons (magnocells) in the hypothalamic paraventricular nucleus (PVN). Here, we used in vivo extracellular recording, juxtacellular labeling, post-hoc anatomo-immunohistochemical analysis and camera lucida reconstruction to address this question. We demonstrate that all well-labeled AVP immunopositive neurons inside the PVN possess main axons joining the tract of Greving and multi-axon-like processes, as well as axonal collaterals branching very near to the somata, which project to extra-neurohypophyseal regions. The detected regions in this study include the medial and lateral preoptical area, suprachiasmatic nucleus (SCN), lateral habenula (LHb), medial and central amygdala and the conducting systems, such as stria medullaris, the fornix and the internal capsule. Expression of vesicular glutamate transporter 2 was observed in axon-collaterals. These results, in congruency with several previous reports in the literature, provided unequivocal evidence that AVP magnocells have an uncommon feature of possessing multiple axon-like processes emanating from somata or proximal dendrites. Furthermore, the long-range non-neurohypophyseal projections are more common than an “occasional” phenomenon as previously thought.
Collapse
Affiliation(s)
- Vito S Hernández
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Erika Vázquez-Juárez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Mariana M Márquez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Fernando Jáuregui-Huerta
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara Guadalajara, Mexico
| | - Rafael A Barrio
- Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Limei Zhang
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico
| |
Collapse
|
49
|
Buzsáki G. Hippocampal sharp wave-ripple: A cognitive biomarker for episodic memory and planning. Hippocampus 2015; 25:1073-188. [PMID: 26135716 PMCID: PMC4648295 DOI: 10.1002/hipo.22488] [Citation(s) in RCA: 943] [Impact Index Per Article: 104.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 06/30/2015] [Indexed: 12/23/2022]
Abstract
Sharp wave ripples (SPW-Rs) represent the most synchronous population pattern in the mammalian brain. Their excitatory output affects a wide area of the cortex and several subcortical nuclei. SPW-Rs occur during "off-line" states of the brain, associated with consummatory behaviors and non-REM sleep, and are influenced by numerous neurotransmitters and neuromodulators. They arise from the excitatory recurrent system of the CA3 region and the SPW-induced excitation brings about a fast network oscillation (ripple) in CA1. The spike content of SPW-Rs is temporally and spatially coordinated by a consortium of interneurons to replay fragments of waking neuronal sequences in a compressed format. SPW-Rs assist in transferring this compressed hippocampal representation to distributed circuits to support memory consolidation; selective disruption of SPW-Rs interferes with memory. Recently acquired and pre-existing information are combined during SPW-R replay to influence decisions, plan actions and, potentially, allow for creative thoughts. In addition to the widely studied contribution to memory, SPW-Rs may also affect endocrine function via activation of hypothalamic circuits. Alteration of the physiological mechanisms supporting SPW-Rs leads to their pathological conversion, "p-ripples," which are a marker of epileptogenic tissue and can be observed in rodent models of schizophrenia and Alzheimer's Disease. Mechanisms for SPW-R genesis and function are discussed in this review.
Collapse
Affiliation(s)
- György Buzsáki
- The Neuroscience Institute, School of Medicine and Center for Neural Science, New York University, New York, New York
| |
Collapse
|
50
|
Kann O. The interneuron energy hypothesis: Implications for brain disease. Neurobiol Dis 2015; 90:75-85. [PMID: 26284893 DOI: 10.1016/j.nbd.2015.08.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/22/2015] [Accepted: 08/12/2015] [Indexed: 12/12/2022] Open
Abstract
Fast-spiking, inhibitory interneurons - prototype is the parvalbumin-positive (PV+) basket cell - generate action potentials at high frequency and synchronize the activity of numerous excitatory principal neurons, such as pyramidal cells, during fast network oscillations by rhythmic inhibition. For this purpose, fast-spiking, PV+ interneurons have unique electrophysiological characteristics regarding action potential kinetics and ion conductances, which are associated with high energy expenditure. This is reflected in the neural ultrastructure by enrichment with mitochondria and cytochrome c oxidase, indicating the dependence on oxidative phosphorylation for adenosine-5'-triphosphate (ATP) generation. The high energy expenditure is most likely required for membrane ion transport in dendrites and the extensive axon arbor as well as for presynaptic release of neurotransmitter, gamma-aminobutyric acid (GABA). Fast-spiking, PV+ interneurons are central for the emergence of gamma oscillations (30-100Hz) that provide a fundamental mechanism of complex information processing during sensory perception, motor behavior and memory formation in networks of the hippocampus and the neocortex. Conversely, shortage in glucose and oxygen supply (metabolic stress) and/or excessive formation of reactive oxygen and nitrogen species (oxidative stress) may render these interneurons to be a vulnerable target. Dysfunction in fast-spiking, PV+ interneurons might set a low threshold for impairment of fast network oscillations and thus higher brain functions. This pathophysiological mechanism might be highly relevant for cerebral aging as well as various acute and chronic brain diseases, such as stroke, vascular cognitive impairment, epilepsy, Alzheimer's disease and schizophrenia.
Collapse
Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany.
| |
Collapse
|