1
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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.
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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.
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2
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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.
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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
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3
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Handwerk CJ, Denzler CJ, Kalinowski AR, Cook HN, Rodriguez HV, Bland KM, Brett CA, Swinehart BD, Vinson EC, Vidal GS. Integrin β3 regulates apical dendritic morphology of pyramidal neurons throughout hippocampal CA3. Hippocampus 2023; 33:936-947. [PMID: 36967540 PMCID: PMC10952146 DOI: 10.1002/hipo.23530] [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: 08/30/2022] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/29/2023]
Abstract
In excitatory hippocampal pyramidal neurons, integrin β3 is critical for synaptic maturation and plasticity in vitro. Itgb3 is a potential autism susceptibility gene that regulates dendritic morphology in the cerebral cortex in a cell-specific manner. However, it is unknown what role Itgb3 could have in regulating hippocampal pyramidal dendritic morphology in vivo, a key feature that is aberrant in many forms of autism and intellectual disability. We found that Itgb3 mRNA is expressed in the stratum pyramidale of CA3. We examined the apical dendritic morphology of CA3 hippocampal pyramidal neurons in conditional Itgb3 knockouts and controls, utilizing the Thy1-GFP-M line. We fully reconstructed the apical dendrite of each neuron and determined each neuron's precise location along the dorsoventral, proximodistal, and radial axes of the stratum pyramidale. We found a very strong effect for Itgb3 expression on CA3 apical dendritic morphology: neurons from conditional Itgb3 knockouts had longer and thinner apical dendrites than controls, particularly in higher branch orders. We also assessed potential relationships between pairs of topographic or morphological variables, finding that most variable pairs were free from any linear relationships to each other. We also found that some neurons from controls, but not conditional Itgb3 knockouts, had a graded pattern of overall diameter along the dorsoventral and proximodistal axes of the stratum pyramidale of CA3. Taken together, Itgb3 is essential for constructing normal dendritic morphology in pyramidal neurons throughout CA3.
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Affiliation(s)
| | - Collin J. Denzler
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Anna R. Kalinowski
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Hollyn N. Cook
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Hilda V. Rodriguez
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Katherine M. Bland
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Cooper A. Brett
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Brian D. Swinehart
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - Elizabeth C. Vinson
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
| | - George S. Vidal
- Department of BiologyJames Madison UniversityMSC 7801, HarrisonburgVirginia22807USA
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4
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Eom K, Lee HR, Hyun JH, An H, Lee YS, Ho WK, Lee SH. Gradual decorrelation of CA3 ensembles associated with contextual discrimination learning is impaired by Kv1.2 insufficiency. Hippocampus 2022; 32:193-216. [PMID: 34964210 DOI: 10.1002/hipo.23400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/30/2021] [Accepted: 12/12/2021] [Indexed: 12/13/2022]
Abstract
The associative network of hippocampal CA3 is thought to contribute to rapid formation of contextual memory from one-trial learning, but the network mechanisms underlying decorrelation of neuronal ensembles in CA3 is largely unknown. Kv1.2 expressions in rodent CA3 pyramidal cells (CA3-PCs) are polarized to distal apical dendrites, and its downregulation specifically enhances dendritic responses to perforant pathway (PP) synaptic inputs. We found that haploinsufficiency of Kv1.2 (Kcna2+/-) in CA3-PCs, but not Kv1.1 (Kcna1+/-), lowers the threshold for long-term potentiation (LTP) at PP-CA3 synapses, and that the Kcna2+/- mice are normal in discrimination of distinct contexts but impaired in discrimination of similar but slightly distinct contexts. We further examined the neuronal ensembles in CA3 and dentate gyrus (DG), which represent the two similar contexts using in situ hybridization of immediate early genes, Homer1a and Arc. The size and overlap of CA3 ensembles activated by the first visit to the similar contexts were not different between wild type and Kcna2+/- mice, but these ensemble parameters diverged over training days between genotypes, suggesting that abnormal plastic changes at PP-CA3 synapses of Kcna2+/- mice is responsible for the impaired pattern separation. Unlike CA3, DG ensembles were not different between two genotype mice. The DG ensembles were already separated on the first day, and their overlap did not further evolve. Eventually, the Kcna2+/- mice exhibited larger CA3 ensemble size and overlap upon retrieval of two contexts, compared to wild type or Kcna1+/- mice. These results suggest that sparse LTP at PP-CA3 synapse probably supervised by mossy fiber inputs is essential for gradual decorrelation of CA3 ensembles.
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Affiliation(s)
- Kisang Eom
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyoung Ro Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung Ho Hyun
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyunhoe An
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
| | - Yong-Seok Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Won-Kyung Ho
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
| | - Suk-Ho Lee
- Cell Physiology Laboratory, Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Brain and Cognitive Science, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
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5
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Yu GJ, Bouteiller JMC, Berger TW. Topographic Organization of Correlation Along the Longitudinal and Transverse Axes in Rat Hippocampal CA3 Due to Excitatory Afferents. Front Comput Neurosci 2020; 14:588881. [PMID: 33328947 PMCID: PMC7715032 DOI: 10.3389/fncom.2020.588881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/22/2020] [Indexed: 11/13/2022] Open
Abstract
The topographic organization of afferents to the hippocampal CA3 subfield are well-studied, but their role in influencing the spatiotemporal dynamics of population activity is not understood. Using a large-scale, computational neuronal network model of the entorhinal-dentate-CA3 system, the effects of the perforant path, mossy fibers, and associational system on the propagation and transformation of network spiking patterns were investigated. A correlation map was constructed to characterize the spatial structure and temporal evolution of pairwise correlations which underlie the emergent patterns found in the population activity. The topographic organization of the associational system gave rise to changes in the spatial correlation structure along the longitudinal and transverse axes of the CA3. The resulting gradients may provide a basis for the known functional organization observed in hippocampus.
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Affiliation(s)
- Gene J Yu
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Jean-Marie C Bouteiller
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Theodore W Berger
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
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Intracellular Zn 2+ Signaling Facilitates Mossy Fiber Input-Induced Heterosynaptic Potentiation of Direct Cortical Inputs in Hippocampal CA3 Pyramidal Cells. J Neurosci 2019; 39:3812-3831. [PMID: 30833508 DOI: 10.1523/jneurosci.2130-18.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023] Open
Abstract
Repetitive action potentials (APs) in hippocampal CA3 pyramidal cells (CA3-PCs) backpropagate to distal apical dendrites, and induce calcium and protein tyrosine kinase (PTK)-dependent downregulation of Kv1.2, resulting in long-term potentiation of direct cortical inputs and intrinsic excitability (LTP-IE). When APs were elicited by direct somatic stimulation of CA3-PCs from rodents of either sex, only a narrow window of distal dendritic [Ca2+] allowed LTP-IE because of Ca2+-dependent coactivation of PTK and protein tyrosine phosphatase (PTP), which renders non-mossy fiber (MF) inputs incompetent in LTP-IE induction. High-frequency MF inputs, however, could induce LTP-IE at high dendritic [Ca2+] of the window. We show that MF input-induced Zn2+ signaling inhibits postsynaptic PTP, and thus enables MF inputs to induce LTP-IE at a wide range of [Ca2+]i values. Extracellular chelation of Zn2+ or genetic deletion of vesicular zinc transporter abrogated the privilege of MF inputs for LTP-IE induction. Moreover, the incompetence of somatic stimulation was rescued by the inhibition of PTP or a supplement of extracellular zinc, indicating that MF input-induced increase in dendritic [Zn2+] facilitates the induction of LTP-IE by inhibiting PTP. Consistently, high-frequency MF stimulation induced immediate and delayed elevations of [Zn2+] at proximal and distal dendrites, respectively. These results indicate that MF inputs are uniquely linked to the regulation of direct cortical inputs owing to synaptic Zn2+ signaling.SIGNIFICANCE STATEMENT Zn2+ has been mostly implicated in pathological processes, and the physiological roles of synaptically released Zn2+ in intracellular signaling are little known. We show here that Zn2+ released from hippocampal mossy fiber (MF) terminals enters postsynaptic CA3 pyramidal cells, and plays a facilitating role in MF input-induced heterosynaptic potentiation of perforant path (PP) synaptic inputs through long-term potentiation of intrinsic excitability (LTP-IE). We show that the window of cytosolic [Ca2+] that induces LTP-IE is normally very narrow because of the Ca2+-dependent coactivation of antagonistic signaling pairs, whereby non-MF inputs become ineffective in inducing excitability change. The MF-induced Zn2+ signaling, however, biases toward facilitating the induction of LTP-IE. The present study elucidates why MF inputs are more privileged for the regulation of PP synapses.
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7
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Ferrante M, Tahvildari B, Duque A, Hadzipasic M, Salkoff D, Zagha EW, Hasselmo ME, McCormick DA. Distinct Functional Groups Emerge from the Intrinsic Properties of Molecularly Identified Entorhinal Interneurons and Principal Cells. Cereb Cortex 2018; 27:3186-3207. [PMID: 27269961 DOI: 10.1093/cercor/bhw143] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inhibitory interneurons are an important source of synaptic inputs that may contribute to network mechanisms for coding of spatial location by entorhinal cortex (EC). The intrinsic properties of inhibitory interneurons in the EC of the mouse are mostly undescribed. Intrinsic properties were recorded from known cell types, such as, stellate and pyramidal cells and 6 classes of molecularly identified interneurons (regulator of calcineurin 2, somatostatin, serotonin receptor 3a, neuropeptide Y neurogliaform (NGF), neuropeptide Y non-NGF, and vasoactive intestinal protein) in acute brain slices. We report a broad physiological diversity between and within cell classes. We also found differences in the ability to produce postinhibitory rebound spikes and in the frequency and amplitude of incoming EPSPs. To understand the source of this intrinsic variability we applied hierarchical cluster analysis to functionally classify neurons. These analyses revealed physiologically derived cell types in EC that mostly corresponded to the lines identified by biomarkers with a few unexpected and important differences. Finally, we reduced the complex multidimensional space of intrinsic properties to the most salient five that predicted the cellular biomolecular identity with 81.4% accuracy. These results provide a framework for the classification of functional subtypes of cortical neurons by their intrinsic membrane properties.
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Affiliation(s)
- Michele Ferrante
- Center for Memory and Brain.,Center for Systems Neuroscience.,Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - Babak Tahvildari
- Department of Neurobiology.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
| | - Alvaro Duque
- Department of Neurobiology.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
| | - Muhamed Hadzipasic
- Interdepartmental Program in Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
| | - David Salkoff
- Department of Neurobiology.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
| | - Edward William Zagha
- Department of Neurobiology.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
| | - Michael E Hasselmo
- Center for Memory and Brain.,Center for Systems Neuroscience.,Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - David A McCormick
- Department of Neurobiology.,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06520-8001, USA
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8
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Excitatory Synaptic Input to Hilar Mossy Cells under Basal and Hyperexcitable Conditions. eNeuro 2017; 4:eN-NWR-0364-17. [PMID: 29214210 PMCID: PMC5714709 DOI: 10.1523/eneuro.0364-17.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 11/06/2017] [Accepted: 11/10/2017] [Indexed: 11/21/2022] Open
Abstract
Hilar mossy cells (HMCs) in the hippocampus receive glutamatergic input from dentate granule cells (DGCs) via mossy fibers (MFs) and back-projections from CA3 pyramidal neuron collateral axons. Many fundamental features of these excitatory synapses have not been characterized in detail despite their potential relevance to hippocampal cognitive processing and epilepsy-induced adaptations in circuit excitability. In this study, we compared pre- and postsynaptic parameters between MF and CA3 inputs to HMCs in young and adult mice of either sex and determined the relative contributions of the respective excitatory inputs during in vitro and in vivo models of hippocampal hyperexcitability. The two types of excitatory synapses both exhibited a modest degree of short-term plasticity, with MF inputs to HMCs exhibiting lower paired-pulse (PP) and frequency facilitation than was described previously for MF–CA3 pyramidal cell synapses. MF–HMC synapses exhibited unitary excitatory synaptic currents (EPSCs) of larger amplitude, contained postsynaptic kainate receptors, and had a lower NMDA/AMPA receptor ratio compared to CA3–HMC synapses. Pharmacological induction of hippocampal hyperexcitability in vitro transformed the abundant but relatively weak CA3–HMC connections to very large amplitude spontaneous bursts of compound EPSCs (cEPSCs) in young mice (∼P20) and, to a lesser degree, in adult mice (∼P70). CA3–HMC cEPSCs were also observed in slices prepared from mice with spontaneous seizures several weeks after intrahippocampal kainate injection. Strong excitation of HMCs during synchronous CA3 activity represents an avenue of significant excitatory network generation back to DGCs and might be important in generating epileptic networks.
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Ferrante M, Shay CF, Tsuno Y, William Chapman G, Hasselmo ME. Post-Inhibitory Rebound Spikes in Rat Medial Entorhinal Layer II/III Principal Cells: In Vivo, In Vitro, and Computational Modeling Characterization. Cereb Cortex 2017; 27:2111-2125. [PMID: 26965902 DOI: 10.1093/cercor/bhw058] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Medial entorhinal cortex Layer-II stellate cells (mEC-LII-SCs) primarily interact via inhibitory interneurons. This suggests the presence of alternative mechanisms other than excitatory synaptic inputs for triggering action potentials (APs) in stellate cells during spatial navigation. Our intracellular recordings show that the hyperpolarization-activated cation current (Ih) allows post-inhibitory-rebound spikes (PIRS) in mEC-LII-SCs. In vivo, strong inhibitory-post-synaptic potentials immediately preceded most APs shortening their delay and enhancing excitability. In vitro experiments showed that inhibition initiated spikes more effectively than excitation and that more dorsal mEC-LII-SCs produced faster and more synchronous spikes. In contrast, PIRS in Layer-II/III pyramidal cells were harder to evoke, voltage-independent, and slower in dorsal mEC. In computational simulations, mEC-LII-SCs morphology and Ih homeostatically regulated the dorso-ventral differences in PIRS timing and most dendrites generated PIRS with a narrow range of stimulus amplitudes. These results suggest inhibitory inputs could mediate the emergence of grid cell firing in a neuronal network.
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Affiliation(s)
- Michele Ferrante
- Center for Memory and Brain.,Department of Psychological and Brain Sciences
| | - Christopher F Shay
- Center for Memory and Brain.,Department of Psychological and Brain Sciences.,Graduate Program for Neuroscience (GPN)
| | - Yusuke Tsuno
- Center for Memory and Brain.,Department of Psychological and Brain Sciences
| | | | - Michael E Hasselmo
- Center for Memory and Brain.,Department of Psychological and Brain Sciences.,Graduate Program for Neuroscience (GPN).,Center for Systems Neuroscience, Boston University, Boston, MA 02215, USA
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10
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Rebola N, Carta M, Mulle C. Operation and plasticity of hippocampal CA3 circuits: implications for memory encoding. Nat Rev Neurosci 2017; 18:208-220. [DOI: 10.1038/nrn.2017.10] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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11
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Lippi G, Fernandes CC, Ewell LA, John D, Romoli B, Curia G, Taylor SR, Frady EP, Jensen AB, Liu JC, Chaabane MM, Belal C, Nathanson JL, Zoli M, Leutgeb JK, Biagini G, Yeo GW, Berg DK. MicroRNA-101 Regulates Multiple Developmental Programs to Constrain Excitation in Adult Neural Networks. Neuron 2016; 92:1337-1351. [PMID: 27939580 DOI: 10.1016/j.neuron.2016.11.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 10/07/2016] [Accepted: 11/03/2016] [Indexed: 11/15/2022]
Abstract
A critical feature of neural networks is that they balance excitation and inhibition to prevent pathological dysfunction. How this is achieved is largely unknown, although deficits in the balance contribute to many neurological disorders. We show here that a microRNA (miR-101) is a key orchestrator of this essential feature, shaping the developing network to constrain excitation in the adult. Transient early blockade of miR-101 induces long-lasting hyper-excitability and persistent memory deficits. Using target site blockers in vivo, we identify multiple developmental programs regulated in parallel by miR-101 to achieve balanced networks. Repression of one target, NKCC1, initiates the switch in γ-aminobutyric acid (GABA) signaling, limits early spontaneous activity, and constrains dendritic growth. Kif1a and Ank2 are targeted to prevent excessive synapse formation. Simultaneous de-repression of these three targets completely phenocopies major dysfunctions produced by miR-101 blockade. Our results provide new mechanistic insight into brain development and suggest novel candidates for therapeutic intervention.
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Affiliation(s)
- Giordano Lippi
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Catarina C Fernandes
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Laura A Ewell
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Danielle John
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Benedetto Romoli
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Seth R Taylor
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - E Paxon Frady
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anne B Jensen
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jerry C Liu
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Melanie M Chaabane
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cherine Belal
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason L Nathanson
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michele Zoli
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Jill K Leutgeb
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Gene W Yeo
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Darwin K Berg
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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12
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Ferrante M, Ascoli GA. Distinct and synergistic feedforward inhibition of pyramidal cells by basket and bistratified interneurons. Front Cell Neurosci 2015; 9:439. [PMID: 26594151 PMCID: PMC4633480 DOI: 10.3389/fncel.2015.00439] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/22/2015] [Indexed: 01/14/2023] Open
Abstract
Feedforward inhibition (FFI) enables pyramidal cells in area CA1 of the hippocampus (CA1PCs) to remain easily excitable while faithfully representing a broad range of excitatory inputs without quickly saturating. Despite the cortical ubiquity of FFI, its specific function is not completely understood. FFI in CA1PCs is mediated by two physiologically and morphologically distinct GABAergic interneurons: fast-spiking, perisomatic-targeting basket cells and regular-spiking, dendritic-targeting bistratified cells. These two FFI pathways might create layer-specific computational sub-domains within the same CA1PC, but teasing apart their specific contributions remains experimentally challenging. We implemented a biophysically realistic model of CA1PCs using 40 digitally reconstructed morphologies and constraining synaptic numbers, locations, amplitude, and kinetics with available experimental data. First, we validated the model by reproducing the known combined basket and bistratified FFI of CA1PCs at the population level. We then analyzed how the two interneuron types independently affected the CA1PC spike probability and timing as a function of inhibitory strength. Separate FFI by basket and bistratified respectively modulated CA1PC threshold and gain. Concomitant FFI by both interneuron types synergistically extended the dynamic range of CA1PCs by buffering their spiking response to excitatory stimulation. These results suggest testable hypotheses on the precise effects of GABAergic diversity on cortical computation.
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Affiliation(s)
- Michele Ferrante
- Computational Neurophysiology Laboratory, Center for Memory and Brain, Psychology Department, Boston University Boston, MA, USA
| | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University Fairfax, VA, USA
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Hyun JH, Eom K, Lee KH, Bae JY, Bae YC, Kim MH, Kim S, Ho WK, Lee SH. Kv1.2 mediates heterosynaptic modulation of direct cortical synaptic inputs in CA3 pyramidal cells. J Physiol 2015; 593:3617-43. [PMID: 26047212 DOI: 10.1113/jp270372] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/26/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We investigated the cellular mechanisms underlying mossy fibre-induced heterosynaptic long-term potentiation of perforant path (PP) inputs to CA3 pyramidal cells. Here we show that this heterosynaptic potentiation is mediated by downregulation of Kv1.2 channels. The downregulation of Kv1.2 preferentially enhanced PP-evoked EPSPs which occur at distal apical dendrites. Such enhancement of PP-EPSPs required activation of dendritic Na(+) channels, and its threshold was lowered by downregulation of Kv1.2. Our results may provide new insights into the long-standing question of how mossy fibre inputs constrain the CA3 network to sparsely represent direct cortical inputs. ABSTRACT A short high frequency stimulation of mossy fibres (MFs) induces long-term potentiation (LTP) of direct cortical or perforant path (PP) synaptic inputs in hippocampal CA3 pyramidal cells (CA3-PCs). However, the cellular mechanism underlying this heterosynaptic modulation remains elusive. Previously, we reported that repetitive somatic firing at 10 Hz downregulates Kv1.2 in the CA3-PCs. Here, we show that MF inputs induce similar somatic firing and downregulation of Kv1.2 in the CA3-PCs. The effect of Kv1.2 downregulation was specific to PP synaptic inputs that arrive at distal apical dendrites. We found that the somatodendritic expression of Kv1.2 is polarized to distal apical dendrites. Compartmental simulations based on this finding suggested that passive normalization of synaptic inputs and polarized distributions of dendritic ionic channels may facilitate the activation of dendritic Na(+) channels preferentially at distal apical dendrites. Indeed, partial block of dendritic Na(+) channels using 10 nm tetrodotoxin brought back the enhanced PP-evoked excitatory postsynaptic potentials (PP-EPSPs) to the baseline level. These results indicate that activity-dependent downregulation of Kv1.2 in CA3-PCs mediates MF-induced heterosynaptic LTP of PP-EPSPs by facilitating activation of Na(+) channels at distal apical dendrites.
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Affiliation(s)
- Jung Ho Hyun
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Kisang Eom
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Kyu-Hee Lee
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Jin Young Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 700-412, Republic of Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, 700-412, Republic of Korea
| | - Myoung-Hwan Kim
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Sooyun Kim
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Won-Kyung Ho
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
| | - Suk-Ho Lee
- Cell Physiology Laboratory, Department of Physiology and bioMembrane Plasticity Research Centre, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul National University Medical Research Centre, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, Republic of Korea
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Mishra P, Narayanan R. High-conductance states and A-type K+ channels are potential regulators of the conductance-current balance triggered by HCN channels. J Neurophysiol 2015; 113:23-43. [DOI: 10.1152/jn.00601.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An increase in the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel conductance reduces input resistance, whereas the consequent increase in the inward h current depolarizes the membrane. This results in a delicate and unique conductance-current balance triggered by the expression of HCN channels. In this study, we employ experimentally constrained, morphologically realistic, conductance-based models of hippocampal neurons to explore certain aspects of this conductance-current balance. First, we found that the inclusion of an experimentally determined gradient in A-type K+ conductance, but not in M-type K+ conductance, tilts the HCN conductance-current balance heavily in favor of conductance, thereby exerting an overall restorative influence on neural excitability. Next, motivated by the well-established modulation of neuronal excitability by synaptically driven high-conductance states observed under in vivo conditions, we inserted thousands of excitatory and inhibitory synapses with different somatodendritic distributions. We measured the efficacy of HCN channels, independently and in conjunction with other channels, in altering resting membrane potential (RMP) and input resistance ( Rin) when the neuron received randomized or rhythmic synaptic bombardments through variable numbers of synaptic inputs. We found that the impact of HCN channels on average RMP, Rin, firing frequency, and peak-to-peak voltage response was severely weakened under high-conductance states, with the impinging synaptic drive playing a dominant role in regulating these measurements. Our results suggest that the debate on the role of HCN channels in altering excitability should encompass physiological and pathophysiological neuronal states under in vivo conditions and the spatiotemporal interactions of HCN channels with other channels.
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Affiliation(s)
- Poonam Mishra
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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Le Duigou C, Simonnet J, Teleñczuk MT, Fricker D, Miles R. Recurrent synapses and circuits in the CA3 region of the hippocampus: an associative network. Front Cell Neurosci 2014; 7:262. [PMID: 24409118 PMCID: PMC3884140 DOI: 10.3389/fncel.2013.00262] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 12/02/2013] [Indexed: 11/29/2022] Open
Abstract
In the CA3 region of the hippocampus, pyramidal cells excite other pyramidal cells and interneurons. The axons of CA3 pyramidal cells spread throughout most of the region to form an associative network. These connections were first drawn by Cajal and Lorente de No. Their physiological properties were explored to understand epileptiform discharges generated in the region. Synapses between pairs of pyramidal cells involve one or few release sites and are weaker than connections made by mossy fibers on CA3 pyramidal cells. Synapses with interneurons are rather effective, as needed to control unchecked excitation. We examine contributions of recurrent synapses to epileptiform synchrony, to the genesis of sharp waves in the CA3 region and to population oscillations at theta and gamma frequencies. Recurrent connections in CA3, as other associative cortices, have a lower connectivity spread over a larger area than in primary sensory cortices. This sparse, but wide-ranging connectivity serves the functions of an associative network, including acquisition of neuronal representations as activity in groups of CA3 cells and completion involving the recall from partial cues of these ensemble firing patterns.
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Affiliation(s)
- Caroline Le Duigou
- Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM U975, CHU Pitié-Salpêtrière, Université Pierre et Marie Curie Paris, France
| | - Jean Simonnet
- Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM U975, CHU Pitié-Salpêtrière, Université Pierre et Marie Curie Paris, France
| | - Maria T Teleñczuk
- Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM U975, CHU Pitié-Salpêtrière, Université Pierre et Marie Curie Paris, France
| | - Desdemona Fricker
- Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM U975, CHU Pitié-Salpêtrière, Université Pierre et Marie Curie Paris, France
| | - Richard Miles
- Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM U975, CHU Pitié-Salpêtrière, Université Pierre et Marie Curie Paris, France
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Parekh R, Ascoli GA. Neuronal morphology goes digital: a research hub for cellular and system neuroscience. Neuron 2013; 77:1017-38. [PMID: 23522039 PMCID: PMC3653619 DOI: 10.1016/j.neuron.2013.03.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2013] [Indexed: 02/07/2023]
Abstract
The importance of neuronal morphology in brain function has been recognized for over a century. The broad applicability of "digital reconstructions" of neuron morphology across neuroscience subdisciplines has stimulated the rapid development of numerous synergistic tools for data acquisition, anatomical analysis, three-dimensional rendering, electrophysiological simulation, growth models, and data sharing. Here we discuss the processes of histological labeling, microscopic imaging, and semiautomated tracing. Moreover, we provide an annotated compilation of currently available resources in this rich research "ecosystem" as a central reference for experimental and computational neuroscience.
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Affiliation(s)
- Ruchi Parekh
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, 22030, USA
| | - Giorgio A. Ascoli
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, 22030, USA
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