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Noguchi H, Arela JC, Ngo T, Cocas L, Pleasure S. Shh from mossy cells contributes to preventing NSC pool depletion after seizure-induced neurogenesis and in aging. eLife 2023; 12:RP91263. [PMID: 38079471 PMCID: PMC10712957 DOI: 10.7554/elife.91263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023] Open
Abstract
Epileptic seizures induce aberrant neurogenesis from resident neural stem cells (NSCs) in the dentate gyrus of the adult mouse hippocampus, which has been implicated in depletion of the NSC pool and impairment of hippocampal function. However, the mechanisms regulating neurogenesis after seizures remain unknown. Here, we demonstrate that Sonic hedgehog (Shh) from mossy cells is a major source of Shh signaling activity after seizures, by which mossy cells contribute to seizure-induced neurogenesis and maintenance of the NSC pool. Deletion of Shh from mossy cells attenuates seizure-induced neurogenesis. Moreover, in the absence of Shh from mossy cells, NSCs pool are prematurely depleted after seizure-induced proliferation, and NSCs have impaired self-renewal. Likewise, lack of Shh from mossy cells accelerates age-related decline of the NSC pool with accompanying reduction of self-renewal of NSCs outside the context of pathology such as seizures. Together, our findings indicate that Shh from mossy cells is critical to maintain NSCs and to prevent exhaustion from excessive consumption in aging and after seizures.
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Affiliation(s)
- Hirofumi Noguchi
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
| | - Jessica Chelsea Arela
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
| | - Thomas Ngo
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
| | - Laura Cocas
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
- Santa Clara University, Biology Department, Neuroscience ProgramSanta ClaraUnited States
| | - Samuel Pleasure
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
- Programs in Neuroscience and Developmental & Stem Cell Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San FranciscoSan FranciscoUnited States
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2
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Trinh AT, Girardi-Schappo M, Béïque JC, Longtin A, Maler L. Adaptive spike threshold dynamics associated with sparse spiking of hilar mossy cells are captured by a simple model. J Physiol 2023; 601:4397-4422. [PMID: 37676904 DOI: 10.1113/jp283728] [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: 09/15/2022] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Hilar mossy cells (hMCs) in the dentate gyrus (DG) receive inputs from DG granule cells (GCs), CA3 pyramidal cells and inhibitory interneurons, and provide feedback input to GCs. Behavioural and in vivo recording experiments implicate hMCs in pattern separation, navigation and spatial learning. Our experiments link hMC intrinsic excitability to their synaptically evoked in vivo spiking outputs. We performed electrophysiological recordings from DG neurons and found that hMCs displayed an adaptative spike threshold that increased both in proportion to the intensity of injected currents, and in response to spiking itself, returning to baseline over a long time scale, thereby instantaneously limiting their firing rate responses. The hMC activity is additionally limited by a prominent medium after-hyperpolarizing potential (AHP) generated by small conductance K+ channels. We hypothesize that these intrinsic hMC properties are responsible for their low in vivo firing rates. Our findings extend previous studies that compare hMCs, CA3 pyramidal cells and hilar inhibitory cells and provide novel quantitative data that contrast the intrinsic properties of these cell types. We developed a phenomenological exponential integrate-and-fire model that closely reproduces the hMC adaptive threshold nonlinearities with respect to their threshold dependence on input current intensity, evoked spike latency and long-lasting spike-induced increase in spike threshold. Our robust and computationally efficient model is amenable to incorporation into large network models of the DG that will deepen our understanding of the neural bases of pattern separation, spatial navigation and learning. KEY POINTS: Previous studies have shown that hilar mossy cells (hMCs) are implicated in pattern separation and the formation of spatial memory, but how their intrinsic properties relate to their in vivo spiking patterns is still unknown. Here we show that the hMCs display electrophysiological properties that distinguish them from the other hilar cell types including a highly adaptive spike threshold that decays slowly. The spike-dependent increase in threshold combined with an after-hyperpolarizing potential mediated by a slow K+ conductance is hypothesized to be responsible for the low-firing rate of the hMC observed in vivo. The hMC's features are well captured by a modified stochastic exponential integrate-and-fire model that has the unique feature of a threshold intrinsically dependant on both the stimulus intensity and the spiking history. This computational model will allow future work to study how the hMCs can contribute to spatial memory formation and navigation.
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Affiliation(s)
- Anh-Tuan Trinh
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Trøndelag, Norway
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Mauricio Girardi-Schappo
- Departamento de Física, Universidade Federal de Santa Catarina, Santa Catarina, Florianópolis, Brazil
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Claude Béïque
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Brain and Mind Institute, University of Ottawa, Ottawa, Ontario, Canada
- Center for Neural Dynamics, University of Ottawa, Ottawa, Ontario, Canada
| | - André Longtin
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
- Brain and Mind Institute, University of Ottawa, Ottawa, Ontario, Canada
- Center for Neural Dynamics, University of Ottawa, Ottawa, Ontario, Canada
| | - Leonard Maler
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Brain and Mind Institute, University of Ottawa, Ottawa, Ontario, Canada
- Center for Neural Dynamics, University of Ottawa, Ottawa, Ontario, Canada
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3
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Noguchi H, Arela JC, Ngo TT, Cocas L, Pleasure SJ. Shh from mossy cells contributes to preventing NSC pool depletion after seizure-induced neurogenesis and in aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554173. [PMID: 37662214 PMCID: PMC10473584 DOI: 10.1101/2023.08.21.554173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Epileptic seizures induce aberrant neurogenesis from resident neural stem cells (NSCs) in the dentate gyrus of the adult mouse hippocampus, which has been implicated in depletion of the NSC pool and impairment of hippocampal function. However, the mechanisms regulating neurogenesis after seizures remain unknown. Here we demonstrate that Shh from mossy cells is a major source of Shh signaling activity after seizures, by which mossy cells contribute to seizure-induced neurogenesis and maintenance of the NSC pool. Deletion of Shh from mossy cells attenuates seizure-induced neurogenesis. Moreover, in the absence of Shh from mossy cells, NSCs pool are prematurely depleted after seizure-induced proliferation, and NSCs have impaired self-renewal. Likewise, lack of Shh from mossy cells accelerates age-related decline of the NSC pool with accompanying reduction of self-renewal of NSCs outside the context of pathology such as seizures. Together, our findings indicate that Shh from mossy cells is critical to maintain NSCs and to prevent exhaustion from excessive consumption in aging and after seizures.
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4
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Shi HJ, Wang S, Wang XP, Zhang RX, Zhu LJ. Hippocampus: Molecular, Cellular, and Circuit Features in Anxiety. Neurosci Bull 2023; 39:1009-1026. [PMID: 36680709 PMCID: PMC10264315 DOI: 10.1007/s12264-023-01020-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/13/2022] [Indexed: 01/22/2023] Open
Abstract
Anxiety disorders are currently a major psychiatric and social problem, the mechanisms of which have been only partially elucidated. The hippocampus serves as a major target of stress mediators and is closely related to anxiety modulation. Yet so far, its complex anatomy has been a challenge for research on the mechanisms of anxiety regulation. Recent advances in imaging, virus tracking, and optogenetics/chemogenetics have permitted elucidation of the activity, connectivity, and function of specific cell types within the hippocampus and its connected brain regions, providing mechanistic insights into the elaborate organization of the hippocampal circuitry underlying anxiety. Studies of hippocampal neurotransmitter systems, including glutamatergic, GABAergic, cholinergic, dopaminergic, and serotonergic systems, have contributed to the interpretation of the underlying neural mechanisms of anxiety. Neuropeptides and neuroinflammatory factors are also involved in anxiety modulation. This review comprehensively summarizes the hippocampal mechanisms associated with anxiety modulation, based on molecular, cellular, and circuit properties, to provide tailored targets for future anxiety treatment.
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Affiliation(s)
- Hu-Jiang Shi
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Shuang Wang
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Xin-Ping Wang
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Rui-Xin Zhang
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Li-Juan Zhu
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China.
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 201108, China.
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5
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Sun Y, Zweifel LS, Holmes TC, Xu X. Whole-brain input mapping of the lateral versus medial anterodorsal bed nucleus of the stria terminalis in the mouse. Neurobiol Stress 2023; 23:100527. [PMID: 36861029 PMCID: PMC9969273 DOI: 10.1016/j.ynstr.2023.100527] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
The anterior portion of the bed nucleus of the stria terminalis (BNST) modulates fear and stress responses. The anterodorsal BNST (adBNST) can be anatomically subdivided further into the lateral and medial divisions. Although output projections of BNST subregions have been studied, the local and global input connections to these subregions remain poorly understood. To further understand BNST-centered circuit operations, we have applied new viral-genetic tracing and functional circuit mapping to determine detailed synaptic circuit inputs to lateral and medial subregions of adBNST in the mouse. Monosynaptic canine adenovirus type 2 (CAV2) and rabies virus-based retrograde tracers were injected in the adBNST subregions. The amygdalar complex, hypothalamus and hippocampal formation account for the majority of overall inputs to adBNST. However, lateral versus medial adBNST subregions have distinct patterns of long-range cortical and limbic brain inputs. The lateral adBNST has more input connections from prefrontal (prelimbic, infralimbic, cingulate) and insular cortices, anterior thalamus and ectorhinal/perirhinal cortices. In contrast, the medial adBNST received biased inputs from the medial amygdala, lateral septum, hypothalamus nuclei and ventral subiculum. We confirmed long-range functional inputs from the amydalohippocampal area and basolateral amygdala to the adBNST using ChR2-assisted circuit mapping. Selected novel BNST inputs are also validated with the AAV axonal tracing data from the Allen Institute Mouse Brain Connectivity Atlas. Together, these results provide a comprehensive map of the differential afferent inputs to lateral and medial adBNST subregions, and offer new insight into the functional operations of BNST circuitry for stress and anxiety-related behaviors.
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Affiliation(s)
- Yanjun Sun
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697-1275, USA
| | - Larry S. Zweifel
- Department of Psychiatry and Behavioral Sciences and Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Todd C. Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697-4560, USA
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697-1275, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697-1275, USA
- Department of Biomedical Engineering, University of California, Irvine, CA, 92697-2715, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, 92697-2715, USA
- Department of Computer Science, University of California, Irvine, CA, 92697-3435, USA
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697-1275, USA
- Corresponding author. Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697-1275, USA.
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Marosi EL, Arszovszki A, Brunner J, Szabadics J. Similar Presynaptic Action Potential-Calcium Influx Coupling in Two Types of Large Mossy Fiber Terminals Innervating CA3 Pyramidal Cells and Hilar Mossy Cells. eNeuro 2023; 10:ENEURO.0017-23.2023. [PMID: 36697256 PMCID: PMC9907395 DOI: 10.1523/eneuro.0017-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 01/16/2023] [Indexed: 01/26/2023] Open
Abstract
Morphologically similar axon boutons form synaptic contacts with diverse types of postsynaptic cells. However, it is less known to what extent the local axonal excitability, presynaptic action potentials (APs), and AP-evoked calcium influx contribute to the functional diversity of synapses and neuronal activity. This is particularly interesting in synapses that contact cell types that show only subtle cellular differences but fulfill completely different physiological functions. Here, we tested these questions in two synapses that are formed by rat hippocampal granule cells (GCs) onto hilar mossy cells (MCs) and CA3 pyramidal cells, which albeit share several morphologic and synaptic properties but contribute to distinct physiological functions. We were interested in the deterministic steps of the action potential-calcium ion influx coupling as these complex modules may underlie the functional segregation between and within the two cell types. Our systematic comparison using direct axonal recordings showed that AP shapes, Ca2+ currents and their plasticity are indistinguishable in synapses onto these two cell types. These suggest that the complete module that couples granule cell activity to synaptic release is shared by hilar mossy cells and CA3 pyramidal cells. Thus, our findings present an outstanding example for the modular composition of distinct cell types, by which cells employ different components only for those functions that are deterministic for their specialized functions, while many of their main properties are shared.
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Affiliation(s)
| | | | - János Brunner
- Institute of Experimental Medicine, Budapest, 1083, Hungary
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7
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Briquet M, Rocher AB, Alessandri M, Rosenberg N, de Castro Abrantes H, Wellbourne-Wood J, Schmuziger C, Ginet V, Puyal J, Pralong E, Daniel RT, Offermanns S, Chatton JY. Activation of lactate receptor HCAR1 down-modulates neuronal activity in rodent and human brain tissue. J Cereb Blood Flow Metab 2022; 42:1650-1665. [PMID: 35240875 PMCID: PMC9441721 DOI: 10.1177/0271678x221080324] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lactate can be used by neurons as an energy substrate to support their activity. Evidence suggests that lactate also acts on a metabotropic receptor called HCAR1, first described in the adipose tissue. Whether HCAR1 also modulates neuronal circuits remains unclear. In this study, using qRT-PCR, we show that HCAR1 is present in the human brain of epileptic patients who underwent resective surgery. In brain slices from these patients, pharmacological HCAR1 activation using a non-metabolized agonist decreased the frequency of both spontaneous neuronal Ca2+ spiking and excitatory post-synaptic currents (sEPSCs). In mouse brains, we found HCAR1 expression in different regions using a fluorescent reporter mouse line and in situ hybridization. In the dentate gyrus, HCAR1 is mainly present in mossy cells, key players in the hippocampal excitatory circuitry and known to be involved in temporal lobe epilepsy. By using whole-cell patch clamp recordings in mouse and rat slices, we found that HCAR1 activation causes a decrease in excitability, sEPSCs, and miniature EPSCs frequency of granule cells, the main output of mossy cells. Overall, we propose that lactate can be considered a neuromodulator decreasing synaptic activity in human and rodent brains, which makes HCAR1 an attractive target for the treatment of epilepsy.
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Affiliation(s)
- Marc Briquet
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Anne-Bérengère Rocher
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Maxime Alessandri
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Nadia Rosenberg
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Joel Wellbourne-Wood
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Céline Schmuziger
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Vanessa Ginet
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Julien Puyal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Etienne Pralong
- Department of Neurosurgery Service, University Hospital of Lausanne and Faculty of Biology and Medicine, UNIL, Lausanne, Switzerland
| | - Roy Thomas Daniel
- Department of Neurosurgery Service, University Hospital of Lausanne and Faculty of Biology and Medicine, UNIL, Lausanne, Switzerland
| | - Stefan Offermanns
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Jean-Yves Chatton
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.,Cellular Imaging Facility, University of Lausanne, Lausanne, Switzerland
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8
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Jacobsen RI, Nair RR, Obenhaus HA, Donato F, Slettmoen T, Moser MB, Moser EI. All-viral tracing of monosynaptic inputs to single birthdate-defined neurons in the intact brain. CELL REPORTS METHODS 2022; 2:100221. [PMID: 35637903 PMCID: PMC9142754 DOI: 10.1016/j.crmeth.2022.100221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/14/2022] [Accepted: 04/26/2022] [Indexed: 11/25/2022]
Abstract
Neuronal firing patterns are the result of inputs converging onto single cells. Identifying these inputs, anatomically and functionally, is essential to understand how neurons integrate information. Single-cell electroporation of helper genes and subsequent local injection of recombinant rabies viruses enable precise mapping of inputs to individual cells in superficial layers of the intact cortex. However, access to neurons in deeper structures requires more invasive procedures, including removal of overlying tissue. We developed a method that, through a combination of virus injections, allows us to target 4 or fewer hippocampal cells 48% of the time and a single cell 16% of the time in wild-type mice without use of electroporation or tissue aspiration. We identify local and distant monosynaptic inputs that can be functionally characterized in vivo. By expanding the toolbox for monosynaptic circuit tracing, this method will help further our understanding of neuronal integration at the level of single cells.
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Affiliation(s)
- R. Irene Jacobsen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - Rajeevkumar R. Nair
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - Horst A. Obenhaus
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - Flavio Donato
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - Torstein Slettmoen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - May-Britt Moser
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
| | - Edvard I. Moser
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU, Trondheim 7030, Norway
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9
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Galloni AR, Samadzelkava A, Hiremath K, Oumnov R, Milstein AD. Recurrent Excitatory Feedback From Mossy Cells Enhances Sparsity and Pattern Separation in the Dentate Gyrus via Indirect Feedback Inhibition. Front Comput Neurosci 2022; 16:826278. [PMID: 35221956 PMCID: PMC8866186 DOI: 10.3389/fncom.2022.826278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/17/2022] [Indexed: 11/17/2022] Open
Abstract
It is generally appreciated that storing memories of specific events in the mammalian brain, and associating features of the environment with behavioral outcomes requires fine-tuning of the strengths of connections between neurons through synaptic plasticity. It is less understood whether the organization of neuronal circuits comprised of multiple distinct neuronal cell types provides an architectural prior that facilitates learning and memory by generating unique patterns of neuronal activity in response to different stimuli in the environment, even before plasticity and learning occur. Here we simulated a neuronal network responding to sensory stimuli, and systematically determined the effects of specific neuronal cell types and connections on three key metrics of neuronal sensory representations: sparsity, selectivity, and discriminability. We found that when the total amount of input varied considerably across stimuli, standard feedforward and feedback inhibitory circuit motifs failed to discriminate all stimuli without sacrificing sparsity or selectivity. Interestingly, networks that included dedicated excitatory feedback interneurons based on the mossy cells of the hippocampal dentate gyrus exhibited improved pattern separation, a result that depended on the indirect recruitment of feedback inhibition. These results elucidate the roles of cellular diversity and neural circuit architecture on generating neuronal representations with properties advantageous for memory storage and recall.
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10
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Wang KY, Wu JW, Cheng JK, Chen CC, Wong WY, Averkin RG, Tamás G, Nakazawa K, Lien CC. Elevation of hilar mossy cell activity suppresses hippocampal excitability and avoidance behavior. Cell Rep 2021; 36:109702. [PMID: 34525354 DOI: 10.1016/j.celrep.2021.109702] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/09/2021] [Accepted: 08/20/2021] [Indexed: 12/30/2022] Open
Abstract
Modulation of hippocampal dentate gyrus (DG) excitability regulates anxiety. In the DG, glutamatergic mossy cells (MCs) receive the excitatory drive from principal granule cells (GCs) and mediate the feedback excitation and inhibition of GCs. However, the circuit mechanism by which MCs regulate anxiety-related information routing through hippocampal circuits remains unclear. Moreover, the correlation between MC activity and anxiety states is unclear. In this study, we first demonstrate, by means of calcium fiber photometry, that MC activity in the ventral hippocampus (vHPC) of mice increases while they explore anxiogenic environments. Next, juxtacellular recordings reveal that optogenetic activation of MCs preferentially recruits GABAergic neurons, thereby suppressing GCs and ventral CA1 neurons. Finally, chemogenetic excitation of MCs in the vHPC reduces avoidance behaviors in both healthy and anxious mice. These results not only indicate an anxiolytic role of MCs but also suggest that MCs may be a potential therapeutic target for anxiety disorders.
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Affiliation(s)
- Kai-Yi Wang
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Jei-Wei Wu
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Jen-Kun Cheng
- Department of Medicine, Mackay Medical College, New Taipei 252, Taiwan; Department of Anesthesiology, Mackay Memorial Hospital, Taipei 104, Taiwan
| | | | - Wai-Yi Wong
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Robert G Averkin
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Közép fasor 52, Szeged 6726, Hungary
| | - Gábor Tamás
- ELKH-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Közép fasor 52, Szeged 6726, Hungary
| | - Kazu Nakazawa
- Department of Neuroscience, Southern Research, Birmingham, AL 35205, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Cheng-Chang Lien
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan.
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11
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Ma Y, Bayguinov PO, McMahon SM, Scharfman HE, Jackson MB. Direct synaptic excitation between hilar mossy cells revealed with a targeted voltage sensor. Hippocampus 2021; 31:1215-1232. [PMID: 34478219 DOI: 10.1002/hipo.23386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/09/2021] [Accepted: 08/21/2021] [Indexed: 12/18/2022]
Abstract
The dentate gyrus not only gates the flow of information into the hippocampus, it also integrates and processes this information. Mossy cells (MCs) are a major type of excitatory neuron strategically located in the hilus of the dentate gyrus where they can contribute to this processing through networks of synapses with inhibitory neurons and dentate granule cells. Some prior work has suggested that MCs can form excitatory synapses with other MCs, but the role of these synapses in the network activity of the dentate gyrus has received little attention. Here, we investigated synaptic inputs to MCs in mouse hippocampal slices using a genetically encoded hybrid voltage sensor (hVOS) targeted to MCs by Cre-lox technology. This enabled optical recording of voltage changes from multiple MCs simultaneously. Stimulating granule cells and CA3 pyramidal cells activated well-established inputs to MCs and elicited synaptic responses as expected. However, the weak blockade of MC responses to granule cell layer stimulation by DCG-IV raised the possibility of another source of excitation. To evaluate synapses between MCs as this source, single MCs were stimulated focally. Stimulation of one MC above its action potential threshold evoked depolarizing responses in neighboring MCs that depended on glutamate receptors. Short latency responses of MCs to other MCs did not depend on release from granule cell axons. However, granule cells did contribute to the longer latency responses of MCs to stimulation of other MCs. Thus, MCs transmit their activity to other MCs both through direct synaptic coupling and through polysynaptic coupling with dentate granule cells. MC-MC synapses can redistribute information entering the dentate gyrus and thus shape and modulate the electrical activity underlying hippocampal functions such as navigation and memory, as well as excessive excitation during seizures.
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Affiliation(s)
- Yihe Ma
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Peter O Bayguinov
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Shane M McMahon
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Helen E Scharfman
- New York University Langone Health and the Nathan Kline Institute for Psychiatric Research, Orangeburg, New Jersey, USA
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
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12
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Uemura M, Blankvoort S, Tok SSL, Yuan L, Cobar LF, Lit KK, Tashiro A. A neurogenic microenvironment defined by excitatory-inhibitory neuronal circuits in adult dentate gyrus. Cell Rep 2021; 36:109324. [PMID: 34233196 DOI: 10.1016/j.celrep.2021.109324] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 05/23/2021] [Accepted: 06/08/2021] [Indexed: 10/20/2022] Open
Abstract
Adult neurogenesis in the dentate gyrus plays a role in adaptive brain functions such as memory formation. Adding new neurons to a specific locus of a neural circuit with functional needs is an efficient way to achieve such an adaptive function. However, it is unknown whether neurogenesis is linked to local functional demands potentially specified by the activity of neuronal circuits. By examining the distribution of neurogenesis and different types of neuronal activity in the dentate gyrus of freely moving adult rats, we find that neurogenesis is positionally associated with active excitatory neurons, some of which show place-cell activity, but is positionally dissociated from a type of interneuron with high-burst tendency. Our finding suggests that the behaviorally relevant activity of excitatory-inhibitory neuronal circuits can define a microenvironment stimulating/inhibiting neurogenesis. Such local regulation of neurogenesis may contribute to strategic recruitment of new neurons to modify functionally relevant neural circuits.
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Affiliation(s)
- Masato Uemura
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, 7030 Trondheim, Norway
| | - Stefan Blankvoort
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, 7030 Trondheim, Norway
| | - Sean Shui Liang Tok
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Li Yuan
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Luis Fernando Cobar
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Kwok Keung Lit
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Ayumu Tashiro
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, 7030 Trondheim, Norway; School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore.
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13
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Fredes F, Shigemoto R. The role of hippocampal mossy cells in novelty detection. Neurobiol Learn Mem 2021; 183:107486. [PMID: 34214666 DOI: 10.1016/j.nlm.2021.107486] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/29/2021] [Accepted: 06/24/2021] [Indexed: 10/21/2022]
Abstract
At the encounter with a novel environment, contextual memory formation is greatly enhanced, accompanied with increased arousal and active exploration. Although this phenomenon has been widely observed in animal and human daily life, how the novelty in the environment is detected and contributes to contextual memory formation has lately started to be unveiled. The hippocampus has been studied for many decades for its largely known roles in encoding spatial memory, and a growing body of evidence indicates a differential involvement of dorsal and ventral hippocampal divisions in novelty detection. In this brief review article, we discuss the recent findings of the role of mossy cells in the ventral hippocampal moiety in novelty detection and put them in perspective with other novelty-related pathways in the hippocampus. We propose a mechanism for novelty-driven memory acquisition in the dentate gyrus by the direct projection of ventral mossy cells to dorsal dentate granule cells. By this projection, the ventral hippocampus sends novelty signals to the dorsal hippocampus, opening a gate for memory encoding in dentate granule cells based on information coming from the entorhinal cortex. We conclude that, contrary to the presently accepted functional independence, the dorsal and ventral hippocampi cooperate to link the novelty and contextual information, and this dorso-ventral interaction is crucial for the novelty-dependent memory formation.
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Affiliation(s)
- Felipe Fredes
- Department of Biomedicine, Aarhus University, Ole Worms Ale 6, Building 1182, 8000 Aarhus C, Denmark
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg 3400, Austria
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14
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Zhang L, Hernandez VS, Gerfen CR, Jiang SZ, Zavala L, Barrio RA, Eiden LE. Behavioral role of PACAP signaling reflects its selective distribution in glutamatergic and GABAergic neuronal subpopulations. eLife 2021; 10:61718. [PMID: 33463524 PMCID: PMC7875564 DOI: 10.7554/elife.61718] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/18/2021] [Indexed: 01/25/2023] Open
Abstract
The neuropeptide PACAP, acting as a co-transmitter, increases neuronal excitability, which may enhance anxiety and arousal associated with threat conveyed by multiple sensory modalities. The distribution of neurons expressing PACAP and its receptor, PAC1, throughout the mouse nervous system was determined, in register with expression of glutamatergic and GABAergic neuronal markers, to develop a coherent chemoanatomical picture of PACAP role in brain motor responses to sensory input. A circuit role for PACAP was tested by observing Fos activation of brain neurons after olfactory threat cue in wild-type and PACAP knockout mice. Neuronal activation and behavioral response, were blunted in PACAP knock-out mice, accompanied by sharply downregulated vesicular transporter expression in both GABAergic and glutamatergic neurons expressing PACAP and its receptor. This report signals a new perspective on the role of neuropeptide signaling in supporting excitatory and inhibitory neurotransmission in the nervous system within functionally coherent polysynaptic circuits.
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Affiliation(s)
- Limei Zhang
- Department of Physiology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.,Section on Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, United States
| | - Vito S Hernandez
- Department of Physiology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Charles R Gerfen
- Laboratory of Systems Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, United States
| | - Sunny Z Jiang
- Section on Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, United States
| | - Lilian Zavala
- Department of Physiology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Rafael A Barrio
- Section on Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, United States.,Department of Complex Systems, Institute of Physics, National Autonomous University of Mexico (UNAM), Mexico, Mexico
| | - Lee E Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, United States
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15
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Fredes F, Silva MA, Koppensteiner P, Kobayashi K, Joesch M, Shigemoto R. Ventro-dorsal Hippocampal Pathway Gates Novelty-Induced Contextual Memory Formation. Curr Biol 2021; 31:25-38.e5. [PMID: 33065009 PMCID: PMC7808756 DOI: 10.1016/j.cub.2020.09.074] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 09/08/2020] [Accepted: 09/24/2020] [Indexed: 01/07/2023]
Abstract
Novelty facilitates memory formation and is detected by both the dorsal and ventral hippocampus. Although dentate granule cells (GCs) in the dorsal hippocampus are known to mediate the formation of novelty-induced contextual memories, the required pathways and mechanisms remain unclear. Here we demonstrate that a powerful excitatory pathway from mossy cells (MCs) in the ventral hippocampus to dorsal GCs is necessary and sufficient for driving dorsal GC activation in novel environment exploration. In vivo Ca2+ imaging in freely moving mice indicated that this pathway relays environmental novelty. Furthermore, manipulation of ventral MC activity bidirectionally regulates novelty-induced contextual memory acquisition. Our results show that ventral MC activity gates contextual memory formation through an intra-hippocampal interaction activated by environmental novelty.
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Affiliation(s)
- Felipe Fredes
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria; Department of Biomedicine, Aarhus University, Ole Worms Alle 6, Building 1182, 8000 Aarhus C, Denmark.
| | - Maria Alejandra Silva
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Peter Koppensteiner
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Myodaiji, Okazaki, Japan
| | - Maximilian Joesch
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
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16
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Meyer MAA, Anstötz M, Ren LY, Fiske MP, Guedea AL, Grayson VS, Schroth SL, Cicvaric A, Nishimori K, Maccaferri G, Radulovic J. Stress-related memories disrupt sociability and associated patterning of hippocampal activity: a role of hilar oxytocin receptor-positive interneurons. Transl Psychiatry 2020; 10:428. [PMID: 33311459 PMCID: PMC7733596 DOI: 10.1038/s41398-020-01091-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 10/17/2020] [Accepted: 10/29/2020] [Indexed: 02/07/2023] Open
Abstract
In susceptible individuals, memories of stressful experiences can give rise to debilitating socio-affective symptoms. This occurs even when the ability to retrieve such memories is limited, as seen in patients suffering from traumatic amnesia. We therefore hypothesized that the encoding, rather than retrieval, mechanisms of stress-related memories underlie their impact on social and emotional behavior. To test this hypothesis, we used combinations of stress-enhanced and state-dependent fear conditioning, which engage different encoding mechanisms for the formation of stress-related memories. We found that the encoding of stress-enhanced state-dependent memories robustly and sex specifically impairs sociability in male mice and disrupts the asymmetry of dentate gyrus (DG)/CA3 activity accompanying social interactions. These deficits were restored by chemogenetic inactivation of oxytocin receptor-positive interneurons localized in the hilus (Oxtr-HI), and by inactivation of dorsohippocampal efferents to the caudal lateral septum. Together, our data suggest that disrupted patterning of dorsohippocampal DG/CA3 activity underlies stress-induced sociability deficits, and that Oxtr-HI can be a cellular target for improving these deficits.
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Affiliation(s)
- Mariah A. A. Meyer
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Max Anstötz
- grid.16753.360000 0001 2299 3507Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Lynn Y. Ren
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Michael P. Fiske
- grid.16753.360000 0001 2299 3507Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Anita L. Guedea
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Viktoriya S. Grayson
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Samantha L. Schroth
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Ana Cicvaric
- grid.16753.360000 0001 2299 3507Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Katsuhiko Nishimori
- grid.411582.b0000 0001 1017 9540Department of Obesity and Internal Inflammation, Fukushima Medical University, Fukushima, 960-1295 Japan
| | - Gianmaria Maccaferri
- grid.16753.360000 0001 2299 3507Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Jelena Radulovic
- Department of Psychiatry and Behavioral Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA. .,Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA. .,Department of Neuroscience and Department of Psychiatry, Albert Einstein College of Medicine, The Bronx, NY, 10461, USA.
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17
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Morales C, Morici JF, Miranda M, Gallo FT, Bekinschtein P, Weisstaub NV. Neurophotonics Approaches for the Study of Pattern Separation. Front Neural Circuits 2020; 14:26. [PMID: 32587504 PMCID: PMC7298152 DOI: 10.3389/fncir.2020.00026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/20/2020] [Indexed: 11/26/2022] Open
Abstract
Successful memory involves not only remembering over time but also keeping memories distinct. Computational models suggest that pattern separation appears as a highly efficient process to discriminate between overlapping memories. Furthermore, lesion studies have shown that the dentate gyrus (DG) participates in pattern separation. However, these manipulations did not allow identifying the neuronal mechanism underlying pattern separation. The development of different neurophotonics techniques, together with other genetic tools, has been useful for the study of the microcircuit involved in this process. It has been shown that less-overlapped information would generate distinct neuronal representations within the granule cells (GCs). However, because glutamatergic or GABAergic cells in the DG are not functionally or structurally homogeneous, identifying the specific role of the different subpopulations remains elusive. Then, understanding pattern separation requires the ability to manipulate a temporal and spatially specific subset of cells in the DG and ideally to analyze DG cells activity in individuals performing a pattern separation dependent behavioral task. Thus, neurophotonics and calcium imaging techniques in conjunction with activity-dependent promoters and high-resolution microscopy appear as important tools for this endeavor. In this work, we review how different neurophotonics techniques have been implemented in the elucidation of a neuronal network that supports pattern separation alone or in combination with traditional techniques. We discuss the limitation of these techniques and how other neurophotonic techniques could be used to complement the advances presented up to this date.
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Affiliation(s)
- Cristian Morales
- Departamento de Psiquiatria, Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Facundo Morici
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Concejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Magdalena Miranda
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Concejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Francisco Tomás Gallo
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Concejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Concejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Noelia V. Weisstaub
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Concejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
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18
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Oh SJ, Cheng J, Jang JH, Arace J, Jeong M, Shin CH, Park J, Jin J, Greengard P, Oh YS. Hippocampal mossy cell involvement in behavioral and neurogenic responses to chronic antidepressant treatment. Mol Psychiatry 2020; 25:1215-1228. [PMID: 30837688 DOI: 10.1038/s41380-019-0384-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 01/29/2019] [Accepted: 02/14/2019] [Indexed: 12/28/2022]
Abstract
Most antidepressants, including selective serotonin reuptake inhibitors (SSRIs), initiate their drug actions by rapid elevation of serotonin, but they take several weeks to achieve therapeutic onset. This therapeutic delay suggests slow adaptive changes in multiple neuronal subtypes and their neural circuits over prolonged periods of drug treatment. Mossy cells are excitatory neurons in the dentate hilus that regulate dentate gyrus activity and function. Here we show that neuronal activity of hippocampal mossy cells is enhanced by chronic, but not acute, SSRI administration. Behavioral and neurogenic effects of chronic treatment with the SSRI, fluoxetine, are abolished by mossy cell-specific knockout of p11 or Smarca3 or by an inhibition of the p11/AnxA2/SMARCA3 heterohexamer, an SSRI-inducible protein complex. Furthermore, simple chemogenetic activation of mossy cells using Gq-DREADD is sufficient to elevate the proliferation and survival of the neural stem cells. Conversely, acute chemogenetic inhibition of mossy cells using Gi-DREADD impairs behavioral and neurogenic responses to chronic administration of SSRI. The present data establish that mossy cells play a crucial role in mediating the effects of chronic antidepressant medication. Our results indicate that compounds that target mossy cell activity would be attractive candidates for the development of new antidepressant medications.
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Affiliation(s)
- Seo-Jin Oh
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea
| | - Jia Cheng
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Jin-Hyeok Jang
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea
| | - Jeffrey Arace
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Minseok Jeong
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea
| | - Chang-Hoon Shin
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea
| | - Jeongrak Park
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea
| | - Junghee Jin
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Yong-Seok Oh
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyenpung-myeon, Dalseong-gun, Daegu, Republic of Korea.
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19
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Dentate gyrus circuits for encoding, retrieval and discrimination of episodic memories. Nat Rev Neurosci 2020; 21:153-168. [PMID: 32042144 DOI: 10.1038/s41583-019-0260-z] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2019] [Indexed: 12/19/2022]
Abstract
The dentate gyrus (DG) has a key role in hippocampal memory formation. Intriguingly, DG lesions impair many, but not all, hippocampus-dependent mnemonic functions, indicating that the rest of the hippocampus (CA1-CA3) can operate autonomously under certain conditions. An extensive body of theoretical work has proposed how the architectural elements and various cell types of the DG may underlie its function in cognition. Recent studies recorded and manipulated the activity of different neuron types in the DG during memory tasks and have provided exciting new insights into the mechanisms of DG computational processes, particularly for the encoding, retrieval and discrimination of similar memories. Here, we review these DG-dependent mnemonic functions in light of the new findings and explore mechanistic links between the cellular and network properties of, and the computations performed by, the DG.
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20
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Tuncdemir SN, Lacefield CO, Hen R. Contributions of adult neurogenesis to dentate gyrus network activity and computations. Behav Brain Res 2019; 374:112112. [PMID: 31377252 PMCID: PMC6724741 DOI: 10.1016/j.bbr.2019.112112] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/18/2019] [Accepted: 07/24/2019] [Indexed: 01/01/2023]
Abstract
Anatomical observations, theoretical work and lesion experiments have led to the idea that an important function of the dentate gyrus of the mammalian hippocampus is pattern separation, a neural computation that ensures new memories are encoded without interference from previously stored memories that share similar features. The dentate gyrus also exhibits a unique form of neural plasticity that results from the continuous integration of newly born excitatory granule cells, termed adult hippocampal neurogenesis. However, the manner in which adult neurogenesis contributes to dentate gyrus network activity and computations is incompletely understood. Here, we first describe the prevailing models for the role of adult neurogenesis in dentate gyrus network function and then re-evaluate these models in the light of recent findings regarding the in vivo activity of the dentate gyrus and synaptic interactions of adult born granule cells with local circuit components, as well as, inputs, and outputs of the dentate gyrus. We propose that adult neurogenesis provides flexibility for the dentate gyrus to rapidly generate a context specific, distributed representation of important sensory stimuli such as spatial cues, which ultimately gives rise to behavioral discrimination.
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Affiliation(s)
- Sebnem Nur Tuncdemir
- Department of Psychiatry, Division of Systems Neuroscience, Columbia University and the Research Foundation for Mental Hygiene, New York State Psychiatric Institute, NY, USA.
| | - Clay Orion Lacefield
- Department of Psychiatry, Division of Systems Neuroscience, Columbia University and the Research Foundation for Mental Hygiene, New York State Psychiatric Institute, NY, USA
| | - Rene Hen
- Department of Psychiatry, Division of Systems Neuroscience, Columbia University and the Research Foundation for Mental Hygiene, New York State Psychiatric Institute, NY, USA.
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21
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Hashimotodani Y, Karube F, Yanagawa Y, Fujiyama F, Kano M. Supramammillary Nucleus Afferents to the Dentate Gyrus Co-release Glutamate and GABA and Potentiate Granule Cell Output. Cell Rep 2019; 25:2704-2715.e4. [PMID: 30517859 DOI: 10.1016/j.celrep.2018.11.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/28/2018] [Accepted: 10/31/2018] [Indexed: 10/27/2022] Open
Abstract
The supramammillary nucleus (SuM) of the hypothalamus projects to the dentate gyrus (DG) and the CA2 region of the hippocampus. Although the SuM-to-hippocampus circuits have been implicated in spatial and emotional memory formation, little is known about precise neural connections between the SuM and hippocampus. Here, we report that axons of SuM neurons make monosynaptic connections to granule cells (GCs) and GABAergic interneurons, but not to hilar mossy cells, in the DG and co-release glutamate and γ-aminobutyric acid (GABA) at these synapses. Although inputs from the SuM can excite some interneurons, the inputs alone fail to generate spikes in GCs. However, despite the insufficient excitatory drive and GABAergic co-transmission, SuM inputs have net excitatory effects on GCs and can potentiate GC firing when temporally associated with perforant path inputs. Our results indicate that the SuM influences DG information processing by modulating GC outputs.
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Affiliation(s)
- Yuki Hashimotodani
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; Laboratory of Molecular Synaptic Function, Graduate School of Brain Science, Doshisha University, Kyotanabe 610-0394, Japan.
| | - Fuyuki Karube
- Laboratory of Neural Circuitry, Graduate School of Brain Science, Doshisha University, Kyotanabe 610-0394, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Fumino Fujiyama
- Laboratory of Neural Circuitry, Graduate School of Brain Science, Doshisha University, Kyotanabe 610-0394, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo 113-0033, Japan.
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22
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Sun Y, Jin S, Lin X, Chen L, Qiao X, Jiang L, Zhou P, Johnston KG, Golshani P, Nie Q, Holmes TC, Nitz DA, Xu X. CA1-projecting subiculum neurons facilitate object-place learning. Nat Neurosci 2019; 22:1857-1870. [PMID: 31548723 PMCID: PMC6819262 DOI: 10.1038/s41593-019-0496-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 08/09/2019] [Indexed: 11/09/2022]
Abstract
Recent anatomical evidence suggests a functionally significant back-projection pathway from the subiculum to the CA1. Here we show that the afferent circuitry of CA1-projecting subicular neurons is biased by inputs from CA1 inhibitory neurons and the visual cortex, but lacks input from the entorhinal cortex. Efferents of the CA1-projecting subiculum neurons also target the perirhinal cortex, an area strongly implicated in object-place learning. We identify a critical role for CA1-projecting subicular neurons in object-location learning and memory, and show that this projection modulates place-specific activity of CA1 neurons and their responses to displaced objects. Together, these experiments reveal a novel pathway by which cortical inputs, particularly those from the visual cortex, reach the hippocampal output region CA1. Our findings also implicate this circuitry in the formation of complex spatial representations and learning of object-place associations.
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Affiliation(s)
- Yanjun Sun
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA.,Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Suoqin Jin
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Xiaoxiao Lin
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Lujia Chen
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Xin Qiao
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Li Jiang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Pengcheng Zhou
- Department of Statistics and Center for Theoretical Neuroscience, Columbia University, New York, NY, USA
| | - Kevin G Johnston
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.,West Los Angeles VA Medical Center, Los Angeles, CA, USA
| | - Qing Nie
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA.,Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA.
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA. .,Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA. .,Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, USA. .,Department of Computer Science, University of California, Irvine, Irvine, CA, USA.
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23
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Zhu X, Lin K, Liu Q, Yue X, Mi H, Huang X, He X, Wu R, Zheng D, Wei D, Jia L, Wang W, Manyande A, Wang J, Zhang Z, Xu F. Rabies Virus Pseudotyped with CVS-N2C Glycoprotein as a Powerful Tool for Retrograde Neuronal Network Tracing. Neurosci Bull 2019; 36:202-216. [PMID: 31444652 DOI: 10.1007/s12264-019-00423-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 06/17/2019] [Indexed: 02/07/2023] Open
Abstract
Efficient viral vectors for mapping and manipulating long-projection neuronal circuits are crucial in structural and functional studies of the brain. The SAD strain rabies virus with the glycoprotein gene deleted pseudotyped with the N2C glycoprotein (SAD-RV(ΔG)-N2C(G)) shows strong neuro-tropism in cell culture, but its in vivo efficiency for retrograde gene transduction and neuro-tropism have not been systematically characterized. We compared these features in different mouse brain regions for SAD-RV-N2C(G) and two other widely-used retrograde tracers, SAD-RV(ΔG)-B19(G) and rAAV2-retro. We found that SAD-RV(ΔG)-N2C(G) enhanced the infection efficiency of long-projecting neurons by ~10 times but with very similar neuro-tropism, compared with SAD-RV(ΔG)-B19(G). On the other hand, SAD-RV(ΔG)-N2C(G) had an infection efficiency comparable with rAAV2-retro, but a more restricted diffusion range, and broader tropism to different types and regions of long-projecting neuronal populations. These results demonstrate that SAD-RV(ΔG)-N2C(G) can serve as an effective retrograde vector for studying neuronal circuits.
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Affiliation(s)
- Xutao Zhu
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Center for Excellence in Brain Science and Intelligence Technology, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Kunzhang Lin
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430071, China
| | - Qing Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Xinpei Yue
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Huijie Mi
- College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Xiaoping Huang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Xiaobin He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Ruiqi Wu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Danhao Zheng
- College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Dong Wei
- College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Liangliang Jia
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Weilin Wang
- College of Life Sciences, Wuhan University, Wuhan, 430071, China
| | - Anne Manyande
- School of Human and Social Sciences, University of West London, London, UK
| | - Jie Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zhijian Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China.
| | - Fuqiang Xu
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Center for Excellence in Brain Science and Intelligence Technology, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China.
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430071, China.
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Zhang L, Wu C, Martel DT, West M, Sutton MA, Shore SE. Remodeling of cholinergic input to the hippocampus after noise exposure and tinnitus induction in Guinea pigs. Hippocampus 2019; 29:669-682. [PMID: 30471164 PMCID: PMC7357289 DOI: 10.1002/hipo.23058] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/23/2018] [Accepted: 11/03/2018] [Indexed: 01/12/2023]
Abstract
Here, we investigate remodeling of hippocampal cholinergic inputs after noise exposure and determine the relevance of these changes to tinnitus. To assess the effects of noise exposure on the hippocampus, guinea pigs were exposed to unilateral noise for 2 hr and 2 weeks later, immunohistochemistry was performed on hippocampal sections to examine vesicular acetylcholine transporter (VAChT) expression. To evaluate whether the changes in VAChT were relevant to tinnitus, another group of animals was exposed to the same noise band twice to induce tinnitus, which was assessed using gap-prepulse Inhibition of the acoustic startle (GPIAS) 12 weeks after the first noise exposure, followed by immunohistochemistry. Acoustic Brainstem Response (ABR) thresholds were elevated immediately after noise exposure for all experimental animals but returned to baseline levels several days after noise exposure. ABR wave I amplitude-intensity functions did not show any changes after 2 or 12 weeks of recovery compared to baseline levels. In animals assessed 2-weeks following noise-exposure, hippocampal VAChT puncta density decreased on both sides of the brain by 20-60% in exposed animals. By 12 weeks following the initial noise exposure, changes in VAChT puncta density largely recovered to baseline levels in exposed animals that did not develop tinnitus, but remained diminished in animals that developed tinnitus. These tinnitus-specific changes were particularly prominent in hippocampal synapse-rich layers of the dentate gyrus and areas CA3 and CA1, and VAChT density in these regions negatively correlated with tinnitus severity. The robust changes in VAChT labeling in the hippocampus 2 weeks after noise exposure suggest involvement of this circuitry in auditory processing. After chronic tinnitus induction, tinnitus-specific changes occurred in synapse-rich layers of the hippocampus, suggesting that synaptic processing in the hippocampus may play an important role in the pathophysiology of tinnitus.
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Affiliation(s)
- Liqin Zhang
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
- Xiangya Medical School, Central South University, Changsha, Hunan, China
| | - Calvin Wu
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
| | - David T. Martel
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael West
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael A. Sutton
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
- Correspondence to: Michael A. Sutton, Molecular and Behavioral Neuroscience Institute, 5067, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA. Tel: 734-615-2445; ; Susan E. Shore, Kresge Hearing Research Institute, 5434, Medical Science Building, 1100 W. Medical Center Drive, Ann Arbor, MI 48109, USA. Tel: 734-647-2116;
| | - Susan E. Shore
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
- Correspondence to: Michael A. Sutton, Molecular and Behavioral Neuroscience Institute, 5067, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA. Tel: 734-615-2445; ; Susan E. Shore, Kresge Hearing Research Institute, 5434, Medical Science Building, 1100 W. Medical Center Drive, Ann Arbor, MI 48109, USA. Tel: 734-647-2116;
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25
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Development of Local Circuit Connections to Hilar Mossy Cells in the Mouse Dentate Gyrus. eNeuro 2019; 6:eN-NWR-0370-18. [PMID: 30937358 PMCID: PMC6439204 DOI: 10.1523/eneuro.0370-18.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 02/15/2019] [Accepted: 02/22/2019] [Indexed: 12/14/2022] Open
Abstract
Hilar mossy cells in the dentate gyrus (DG) shape the firing and function of the hippocampal circuit. However, the neural circuitry providing afferent input to mossy cells is incompletely understood, and little is known about the development of these inputs. Thus, we used whole-cell recording and laser scanning photostimulation (LSPS) to characterize the developmental trajectory of local excitatory and inhibitory synaptic inputs to mossy cells in the mouse hippocampus. Hilar mossy cells were targeted by visualizing non-red fluorescent cells in the dentate hilus of GAD2-Cre; Ai9 mice that expressed tdTomato in GAD+ neurons, and were confirmed by post hoc morphological characterization. Our results show that at postnatal day (P)6–P7, mossy cells received more excitatory input from neurons in the proximal CA3 versus those in the DG. In contrast, at P13–P14 and P21–P28, the largest source of excitatory input originated in DG cells, while the strength of CA3 and hilar inputs declined. A developmental trend was also evident for inhibitory inputs. Overall inhibitory input at P6–P7 was weak, while inhibitory inputs from the DG cell layer and the hilus predominated at P13–P14 and P21–P28. The strength of local DG excitation and inhibition to mossy cells peaked at P13–P14 and decreased slightly in older P21–P28 mice. Together, these data provide new detailed information on the development of local synaptic connectivity of mossy cells, and suggests mechanisms through which developmental changes in local circuit inputs to hilar mossy cells shape their physiology and vulnerability to injury during postnatal periods.
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26
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Scharfman HE. Advances in understanding hilar mossy cells of the dentate gyrus. Cell Tissue Res 2018; 373:643-652. [PMID: 29222692 PMCID: PMC5993616 DOI: 10.1007/s00441-017-2750-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/21/2017] [Indexed: 02/01/2023]
Abstract
Hilar mossy cells (MCs) of the dentate gyrus (DG) distinguish the DG from other hippocampal subfields (CA1-3) because there are two glutamatergic cell types in the DG rather than one. Thus, in the DG, the main cell types include glutamatergic granule cells (GCs) and MCs, whereas in CA1-3, the only glutamatergic cell type is the pyramidal cell. In contrast to GCs, MCs are different in morphology, intrinsic electrophysiological properties, afferent input and axonal projections, so their function is likely to be very different from GCs. Why are MCs necessary to the DG? In past studies, the answer has been unclear because MCs not only excite GCs directly but also inhibit them disynaptically, by exciting GABAergic neurons that project to GCs. Results of new studies are discussed that shed light on this issue. These studies take advantage of recently available transgenic mice with Cre recombinase expression mostly in MCs and techniques such as optogenetics and DREADDs (designer receptors exclusively activated by designer drugs). The recent studies also address in vivo behavioral functions of MCs. Some of the results support past hypotheses whereas others suggest new conceptualizations of how the MCs contribute to DG circuitry and function. While substantial progess has been made, additional research is still needed to clarify the characteristics and functions of these unique cells.
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Affiliation(s)
- Helen E Scharfman
- Departments of Child & Adolescent Psychiatry, Neuroscience & Physiology, Psychiatry, and the New York University Neuroscience Institute, New York University Langone Medical Center, One Park Avenue, 7th floor, New York, NY, 10016, USA.
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Building 39, Orangeburg, NY, 10962, USA.
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27
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Berglind F, Andersson M, Kokaia M. Dynamic interaction of local and transhemispheric networks is necessary for progressive intensification of hippocampal seizures. Sci Rep 2018; 8:5669. [PMID: 29618778 PMCID: PMC5884800 DOI: 10.1038/s41598-018-23659-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 03/02/2018] [Indexed: 12/02/2022] Open
Abstract
The detailed mechanisms of progressive intensification of seizures often occurring in epilepsy are not well understood. Animal models of kindling, with progressive intensification of stimulation-induced seizures, have been previously used to investigate alterations in neuronal networks, but has been obscured by limited recording capabilities during electrical stimulations. Remote networks in kindling have been studied by physical deletions of the connected structures or pathways, inevitably leading to structural reorganisations and related adverse effects. We used optogenetics to circumvent the above-mentioned problems inherent to electrical kindling, and chemogenetics to temporarily inhibit rather than ablate the remote interconnected networks. Progressively intensifying afterdischarges (ADs) were induced by repetitive photoactivation of principal neurons in the hippocampus of anaesthetized transgenic mice expressing ChR2. This allowed, during the stimulation, to reveal dynamic increases in local field potentials (LFPs), which coincided with the start of AD intensification. Furthermore, chemogenetic functional inhibition of contralateral hippocampal neurons via hM4D(Gi) receptors abrogated AD progression. These findings demonstrate that, during repeated activation, local circuits undergo acute plastic changes with appearance of additional network discharges (LFPs), leading to transhemispheric recruitment of contralateral dentate gyrus, which seems to be necessary for progressive intensification of ADs.
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Affiliation(s)
- Fredrik Berglind
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden
| | - My Andersson
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden
| | - Merab Kokaia
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden.
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28
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Opposing and Complementary Topographic Connectivity Gradients Revealed by Quantitative Analysis of Canonical and Noncanonical Hippocampal CA1 Inputs. eNeuro 2018; 5:eN-NWR-0322-17. [PMID: 29387780 PMCID: PMC5790753 DOI: 10.1523/eneuro.0322-17.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 01/07/2023] Open
Abstract
Physiological studies suggest spatial representation gradients along the CA1 proximodistal axis. To determine the underlying anatomical basis, we quantitatively mapped canonical and noncanonical inputs to excitatory neurons in dorsal hippocampal CA1 along the proximal-distal axis in mice of both sexes using monosynaptic rabies tracing. Our quantitative analyses show comparable strength of subiculum complex and entorhinal cortex (EC) inputs to CA1, significant inputs from presubiculum and parasubiculum to CA1, and a threefold stronger input to proximal versus distal CA1 from CA3. Noncanonical subicular complex inputs exhibit opposing topographic connectivity gradients whereby the subiculum-CA1 input strength systematically increases but the presubiculum-CA1 input strength decreases along the proximal-distal axis. The subiculum input strength cotracks that of the lateral EC, known to be less spatially selective than the medial EC. The functional significance of this organization is verified physiologically for subiculum-to-CA1 inputs. These results reveal a novel anatomical framework by which to determine the circuit bases for CA1 representations.
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29
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Sah N, Peterson BD, Lubejko ST, Vivar C, van Praag H. Running reorganizes the circuitry of one-week-old adult-born hippocampal neurons. Sci Rep 2017; 7:10903. [PMID: 28883658 PMCID: PMC5589841 DOI: 10.1038/s41598-017-11268-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 07/05/2017] [Indexed: 12/23/2022] Open
Abstract
Adult hippocampal neurogenesis is an important form of structural and functional plasticity in the mature mammalian brain. The existing consensus is that GABA regulates the initial integration of adult-born neurons, similar to neuronal development during embryogenesis. Surprisingly, virus-based anatomical tracing revealed that very young, one-week-old, new granule cells in male C57Bl/6 mice receive input not only from GABAergic interneurons, but also from multiple glutamatergic cell types, including mature dentate granule cells, area CA1-3 pyramidal cells and mossy cells. Consistently, patch-clamp recordings from retrovirally labeled new granule cells at 7-8 days post retroviral injection (dpi) show that these cells respond to NMDA application with tonic currents, and that both electrical and optogenetic stimulation can evoke NMDA-mediated synaptic responses. Furthermore, new dentate granule cell number, morphology and excitatory synaptic inputs at 7 dpi are modified by voluntary wheel running. Overall, glutamatergic and GABAergic innervation of newly born neurons in the adult hippocampus develops concurrently, and excitatory input is reorganized by exercise.
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Affiliation(s)
- Nirnath Sah
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Benjamin D Peterson
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Susan T Lubejko
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Carmen Vivar
- Laboratory of Neurogenesis and Neuroplasticity, Department of Physiology, Biophysics, and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, 07360, Mexico.
| | - Henriette van Praag
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA.
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