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Schieferstein N, Del Toro A, Evangelista R, Imbrosci B, Swaminathan A, Schmitz D, Maier N, Kempter R. Propagation of sharp wave-ripple activity in the mouse hippocampal CA3 subfield in vitro. J Physiol 2024. [PMID: 39216085 DOI: 10.1113/jp285671] [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: 09/12/2023] [Accepted: 08/08/2024] [Indexed: 09/04/2024] Open
Abstract
Sharp wave-ripple complexes (SPW-Rs) are spontaneous oscillatory events that characterize hippocampal activity during resting periods and slow-wave sleep. SPW-Rs are related to memory consolidation - the process during which newly acquired memories are transformed into long-lasting memory traces. To test the involvement of SPW-Rs in this process, it is crucial to understand how SPW-Rs originate and propagate throughout the hippocampus. SPW-Rs can originate in CA3, and they typically spread from CA3 to CA1, but little is known about their formation within CA3. To investigate the generation and propagation of SPW-Rs in CA3, we recorded from mouse hippocampal slices using multi-electrode arrays and patch-clamp electrodes. We characterized extracellular and intracellular correlates of SPW-Rs and quantified their propagation along the pyramidal cell layer of CA3. We found that a hippocampal slice can be described by a speed and a direction of propagation of SPW-Rs. The preferred propagation direction was from CA3c (the subfield closer to the dentate gyrus) toward CA3a (the subfield at the boundary to CA2). In patch-clamp recordings from CA3 pyramidal neurons, propagation was estimated separately for excitatory and inhibitory currents associated with SPW-Rs. We found that propagation speed and direction of excitatory and inhibitory currents were correlated. The magnitude of the speed of propagation of SPW-Rs within CA3 was consistent with the speed of propagation of action potentials in axons of CA3 principal cells. KEY POINTS: Hippocampal sharp waves are considered important for memory consolidation; therefore, it is of interest to understand the mechanisms of their generation and propagation. Here, we used two different approaches to study the propagation of sharp waves in mouse CA3 in vitro: multi-electrode arrays and multiple single-cell recordings. We find a preferred direction of propagation of sharp waves from CA3c toward CA3a - both in the local field potential and in sharp wave-associated excitatory and inhibitory synaptic activity. The speed of sharp wave propagation is consistent with the speed of action potential propagation along the axons of CA3 pyramidal neurons. These new insights into the dynamics of sharp waves in the CA3 network will inform future experiments and theoretical models of sharp-wave generation mechanisms.
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Affiliation(s)
- Natalie Schieferstein
- Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Ana Del Toro
- Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Roberta Evangelista
- Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
| | - Barbara Imbrosci
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Aarti Swaminathan
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Dietmar Schmitz
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
- Einstein Center for Neurosciences (ECN) Berlin, Berlin, Germany
| | - Nikolaus Maier
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Richard Kempter
- Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Center for Neurosciences (ECN) Berlin, Berlin, Germany
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2
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Kitchigina V, Shubina L. Oscillations in the dentate gyrus as a tool for the performance of the hippocampal functions: Healthy and epileptic brain. Prog Neuropsychopharmacol Biol Psychiatry 2023; 125:110759. [PMID: 37003419 DOI: 10.1016/j.pnpbp.2023.110759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
The dentate gyrus (DG) is part of the hippocampal formation and is essential for important cognitive processes such as navigation and memory. The oscillatory activity of the DG network is believed to play a critical role in cognition. DG circuits generate theta, beta, and gamma rhythms, which participate in the specific information processing performed by DG neurons. In the temporal lobe epilepsy (TLE), cognitive abilities are impaired, which may be due to drastic alterations in the DG structure and network activity during epileptogenesis. The theta rhythm and theta coherence are especially vulnerable in dentate circuits; disturbances in DG theta oscillations and their coherence may be responsible for general cognitive impairments observed during epileptogenesis. Some researchers suggested that the vulnerability of DG mossy cells is a key factor in the genesis of TLE, but others did not support this hypothesis. The aim of the review is not only to present the current state of the art in this field of research but to help pave the way for future investigations by highlighting the gaps in our knowledge to completely appreciate the role of DG rhythms in brain functions. Disturbances in oscillatory activity of the DG during TLE development may be a diagnostic marker in the treatment of this disease.
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Affiliation(s)
- Valentina Kitchigina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia.
| | - Liubov Shubina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia
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Abdulmajeed WI, Wang KY, Wu JW, Ajibola MI, Cheng IHJ, Lien CC. Connectivity and synaptic features of hilar mossy cells and their effects on granule cell activity along the hippocampal longitudinal axis. J Physiol 2022; 600:3355-3381. [PMID: 35671148 DOI: 10.1113/jp282804] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/01/2022] [Indexed: 11/08/2022] Open
Abstract
The hippocampus is an elongated brain structure which runs along a ventral-to-dorsal axis in rodents, corresponding to the anterior-to-posterior axis in humans. A glutamatergic cell type in the dentate gyrus (DG), the mossy cells (MCs), establishes extensive excitatory collateral connections with the DG principal cells, the granule cells (GCs), and inhibitory interneurons in both hippocampal hemispheres along the longitudinal axis. Although coupling of two physically separated GC populations via long-axis projecting MCs is instrumental for information processing, the connectivity and synaptic features of MCs along the longitudinal axis are poorly defined. Here, using channelrhodopsin-2 assisted circuit mapping, we showed that MC excitation results in a low synaptic excitation-inhibition (E/I) balance in the intralamellar (local) GCs, but a high synaptic E/I balance in the translamellar (distant) ones. In agreement with the differential E/I balance along the ventrodorsal axis, activation of MCs either enhances or suppresses the local GC response to the cortical input, but primarily promotes the distant GC activation. Moreover, activation of MCs enhances the spike timing precision of the local GCs, but not that of the distant ones. Collectively, these findings suggest that MCs differentially regulate the local and distant GC activity through distinct synaptic mechanisms. KEY POINTS: Hippocampal mossy cell (MC) pathways differentially regulate granule cell (GC) activity along the longitudinal axis. MCs mediate a low excitation-inhibition balance in intralamellar (local) GCs, but a high excitation-inhibition balance in translamellar (distant) GCs. MCs enhance the spiking precision of local GCs, but not distant GCs. MCs either promote or suppress local GC activity, but primarily promote distant GC activation.
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Affiliation(s)
- Wahab Imam Abdulmajeed
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, Academia Sinica, Taipei, Taiwan.,Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Kai-Yi Wang
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jei-Wei Wu
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Musa Iyiola Ajibola
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, Academia Sinica, Taipei, Taiwan.,Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Irene Han-Juo Cheng
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, Academia Sinica, Taipei, Taiwan.,Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Cheng-Chang Lien
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, Academia Sinica, Taipei, Taiwan.,Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
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4
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Zhao S, Chen B, Wang H, Luo Z, Zhang T. A Feed-Forward Neural Network for Increasing the Hopfield-Network Storage Capacity. Int J Neural Syst 2022; 32:2250027. [PMID: 35534937 DOI: 10.1142/s0129065722500277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the hippocampal dentate gyrus (DG), pattern separation mainly depends on the concepts of 'expansion recoding', meaning random mixing of different DG input channels. However, recent advances in neurophysiology have challenged the theory of pattern separation based on these concepts. In this study, we propose a novel feed-forward neural network, inspired by the structure of the DG and neural oscillatory analysis, to increase the Hopfield-network storage capacity. Unlike the previously published feed-forward neural networks, our bio-inspired neural network is designed to take advantage of both biological structure and functions of the DG. To better understand the computational principles of pattern separation in the DG, we have established a mouse model of environmental enrichment. We obtained a possible computational model of the DG, associated with better pattern separation ability, by using neural oscillatory analysis. Furthermore, we have developed a new algorithm based on Hebbian learning and coupling direction of neural oscillation to train the proposed neural network. The simulation results show that our proposed network significantly expands the storage capacity of Hopfield network, and more effective pattern separation is achieved. The storage capacity rises from 0.13 for the standard Hopfield network to 0.32 using our model when the overlap in patterns is 10%.
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Affiliation(s)
- Shaokai Zhao
- College of Life Sciences, Nankai University, 300071 Tianjin, P. R. China
| | - Bin Chen
- College of Life Sciences, Nankai University, 300071 Tianjin, P. R. China
| | - Hui Wang
- College of Life Sciences, Nankai University, 300071 Tianjin, P. R. China
| | - Zhiyuan Luo
- Department of Computer Science, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| | - Tao Zhang
- College of Life Sciences, Nankai University, 300071 Tianjin, P. R. China
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Park SB, Lim HY, Lee EY, Yoo SW, Jung HS, Lee E, Sun W, Lee I. The fasciola cinereum subregion of the hippocampus is important for the acquisition of visual contextual memory. Prog Neurobiol 2022; 210:102217. [PMID: 34999186 DOI: 10.1016/j.pneurobio.2022.102217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 11/29/2021] [Accepted: 01/04/2022] [Indexed: 11/15/2022]
Abstract
The fasciola cinereum (FC) is a subregion of the hippocampus that has received relatively little attention compared with other hippocampal subregions with respect to anatomical characteristics and functional significance. Here, we show that the FC exhibits clear anatomical borders with the distalmost region of the CA1. Principal neurons in the FC resemble the granule cells in the dentate gyrus (DG). However, adult neurogenesis was not found unlike in the DG. The FC receives inputs mostly from the lateral entorhinal cortex and perirhinal cortex while projecting exclusively to the crest of the DG within the hippocampus. Neurotoxic lesions in the FC using colchicine impaired the acquisition, but not retrieval, of visual contextual memory in rats. FC lesions also impaired place recognition and object-in-place memory. As the rat performed the contextual memory task on the T-maze, place cells in the FC exhibited robust place fields and were indiscriminable from those in CA1 with respect to the basic firing properties. However, place cells in the FC fired only transiently in their place fields on the maze compared with those in CA1. Our findings suggest that the episodic firing pattern of the place cells in the FC may play critical roles in learning a novel contextual environment by facilitating temoporally structured contextual pattern separation in the DG of the hippocampus.
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Affiliation(s)
- Seong-Beom Park
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Heung-Yeol Lim
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Eun-Young Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seung-Woo Yoo
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Hyun-Suk Jung
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Eunsoo Lee
- Department of Anatomy, College of Medicine, Korea University, Anam-dong 5, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Woong Sun
- Department of Anatomy, College of Medicine, Korea University, Anam-dong 5, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Shillim-dong, Gwanak-gu, Seoul, 08826, Republic of Korea.
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6
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Núñez-Ochoa MA, Chiprés-Tinajero GA, González-Domínguez NP, Medina-Ceja L. Causal relationship of CA3 back-projection to the dentate gyrus and its role in CA1 fast ripple generation. BMC Neurosci 2021; 22:37. [PMID: 34001031 PMCID: PMC8130286 DOI: 10.1186/s12868-021-00641-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/07/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Pathophysiological evidence from temporal lobe epilepsy models highlights the hippocampus as the most affected structure due to its high degree of neuroplasticity and control of the dynamics of limbic structures, which are necessary to encode information, conferring to it an intrinsic epileptogenicity. A loss in this control results in observable oscillatory perturbations called fast ripples, in epileptic rats those events are found in CA1, CA3, and the dentate gyrus (DG), which are the principal regions of the trisynaptic circuit of the hippocampus. The present work used Granger causality to address which relationships among these three regions of the trisynaptic circuit are needed to cause fast ripples in CA1 in an in vivo model. For these purposes, male Wistar rats (210-300 g) were injected with a single dose of pilocarpine hydrochloride (2.4 mg/2 µl) into the right lateral ventricle and video-monitored 24 h/day to detect spontaneous and recurrent seizures. Once detected, rats were implanted with microelectrodes in these regions (fixed-recording tungsten wire electrodes, 60-μm outer diameter) ipsilateral to the pilocarpine injection. A total of 336 fast ripples were recorded and probabilistically characterized, from those fast ripples we made a subset of all the fast ripple events associated with sharp-waves in CA1 region (n = 40) to analyze them with Granger Causality. RESULTS Our results support existing evidence in vitro in which fast ripple events in CA1 are initiated by CA3 multiunit activity and describe a general synchronization in the theta band across the three regions analyzed DG, CA3, and CA1, just before the fast ripple event in CA1 have begun. CONCLUSION This in vivo study highlights the causal participation of the CA3 back-projection to the DG, a connection commonly overlooked in the trisynaptic circuit, as a facilitator of a closed-loop among these regions that prolongs the excitatory activity of CA3. We speculate that the loss of inhibitory drive of DG and the mechanisms of ripple-related memory consolidation in which also the CA3 back-projection to DG has a fundamental role might be underlying processes of the fast ripples generation in CA1.
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Affiliation(s)
- Miguel A Núñez-Ochoa
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Gustavo A Chiprés-Tinajero
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Nadia P González-Domínguez
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico.
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico.
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Sanchez-Aguilera A, Wheeler DW, Jurado-Parras T, Valero M, Nokia MS, Cid E, Fernandez-Lamo I, Sutton N, García-Rincón D, de la Prida LM, Ascoli GA. An update to Hippocampome.org by integrating single-cell phenotypes with circuit function in vivo. PLoS Biol 2021; 19:e3001213. [PMID: 33956790 PMCID: PMC8130934 DOI: 10.1371/journal.pbio.3001213] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 05/18/2021] [Accepted: 03/30/2021] [Indexed: 02/03/2023] Open
Abstract
Understanding brain operation demands linking basic behavioral traits to cell-type specific dynamics of different brain-wide subcircuits. This requires a system to classify the basic operational modes of neurons and circuits. Single-cell phenotyping of firing behavior during ongoing oscillations in vivo has provided a large body of evidence on entorhinal-hippocampal function, but data are dispersed and diverse. Here, we mined literature to search for information regarding the phase-timing dynamics of over 100 hippocampal/entorhinal neuron types defined in Hippocampome.org. We identified missing and unresolved pieces of knowledge (e.g., the preferred theta phase for a specific neuron type) and complemented the dataset with our own new data. By confronting the effect of brain state and recording methods, we highlight the equivalences and differences across conditions and offer a number of novel observations. We show how a heuristic approach based on oscillatory features of morphologically identified neurons can aid in classifying extracellular recordings of single cells and discuss future opportunities and challenges towards integrating single-cell phenotypes with circuit function.
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Affiliation(s)
| | - Diek W. Wheeler
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Virginia, United States of America
| | | | - Manuel Valero
- Instituto Cajal CSIC, Madrid, Spain
- NYU Neuroscience Institute, New York, United States of America
| | - Miriam S. Nokia
- Instituto Cajal CSIC, Madrid, Spain
- Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | | | | | - Nate Sutton
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Virginia, United States of America
| | | | | | - Giorgio A. Ascoli
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Virginia, United States of America
- * E-mail: (LMP); (GAA)
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Imbrosci B, Nitzan N, McKenzie S, Donoso JR, Swaminathan A, Böhm C, Maier N, Schmitz D. Subiculum as a generator of sharp wave-ripples in the rodent hippocampus. Cell Rep 2021; 35:109021. [PMID: 33882307 PMCID: PMC9239734 DOI: 10.1016/j.celrep.2021.109021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/22/2021] [Accepted: 03/31/2021] [Indexed: 12/04/2022] Open
Abstract
Sharp wave-ripples (SWRs) represent synchronous discharges of hippocampal neurons and are believed to play a major role in memory consolidation. A large body of evidence suggests that SWRs are exclusively generated in the CA3-CA2 network. In contrast, here, we provide several lines of evidence showing that the subiculum can function as a secondary SWRs generator. SWRs with subicular origin propagate forward into the entorhinal cortex as well as backward into the hippocampus proper. Our findings suggest that the output structures of the hippocampus are not only passively facilitating the transfer of SWRs to the cortex, but they also can actively contribute to the genesis of SWRs. We hypothesize that SWRs with a subicular origin may be important for the consolidation of information conveyed to the hippocampus via the temporoammonic pathway. Imbrosci et al. show that the subiculum can work as a secondary generator of sharp wave-ripples (SWRs). SWRs with their origin in subiculum can propagate to the entorhinal cortex and backward to CA1 and CA3.
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Affiliation(s)
- Barbara Imbrosci
- German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Noam Nitzan
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Sam McKenzie
- Neuroscience Institute, New York University, New York, NY 10016, USA
| | - José R Donoso
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience (BCCN) Berlin, 10115 Berlin, Germany
| | - Aarti Swaminathan
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Claudia Böhm
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Nikolaus Maier
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Dietmar Schmitz
- German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Charitéplatz 1, 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience (BCCN) Berlin, 10115 Berlin, Germany; Einstein Center for Neurosciences (ECN) Berlin, 10117 Berlin, Germany; Max-Delbrück-Centrum (MDC) for Molecular Medicine, 13125 Berlin, Germany.
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9
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Lothmann K, Deitersen J, Zilles K, Amunts K, Herold C. New boundaries and dissociation of the mouse hippocampus along the dorsal-ventral axis based on glutamatergic, GABAergic and catecholaminergic receptor densities. Hippocampus 2020; 31:56-78. [PMID: 32986281 DOI: 10.1002/hipo.23262] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 08/31/2020] [Accepted: 09/05/2020] [Indexed: 02/01/2023]
Abstract
In rodents, gene-expression, neuronal tuning, connectivity and neurogenesis studies have postulated that the dorsal, the intermediate and the ventral hippocampal formation (HF) are distinct entities. These findings are underpinned by behavioral studies showing a dissociable role of dorsal and ventral HF in learning, memory, stress and emotional processing. However, up to now, the molecular basis of such differences in relation to discrete boundaries is largely unknown. Therefore, we analyzed binding site densities for glutamatergic AMPA, NMDA, kainate and mGluR2/3 , GABAergic GABAA (including benzodiazepine binding sites), GABAB , dopaminergic D1/5 and noradrenergic α1 and α2 receptors as key modulators for signal transmission in hippocampal functions, using quantitative in vitro receptor autoradiography along the dorsal-ventral axis of the mouse HF. Beside general different receptor profiles of the dentate gyrus (DG) and Cornu Ammonis fields (CA1, CA2, CA3, CA4/hilus), we detected substantial differences between dorsal, intermediate and ventral subdivisions and individual layers for all investigated receptor types, except GABAB . For example, striking higher densities of α2 receptors were detected in the ventral DG, while the dorsal DG possesses higher numbers of kainate, NMDA, GABAA and D1/5 receptors. CA1 dorsal and intermediate subdivisions showed higher AMPA, NMDA, mGluR2/3 , GABAA , D1/5 receptors, while kainate receptors are higher expressed in ventral CA1, and noradrenergic α1 and α2 receptors in the intermediate region of CA1. CA2 dorsal was distinguished by higher kainate, α1 and α2 receptors in the intermediate region, while CA3 showed a more complex dissociation. Our findings resulted not only in a clear segmentation of the mouse hippocampus along the dorsal-ventral axis, but also provides insights into the neurochemical basis and likely associated physiological processes in hippocampal functions. Therein, the presented data has a high impact for future studies modeling and investigating dorsal, intermediate and ventral hippocampal dysfunction in relation to neurodegenerative diseases or psychiatric disorders.
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Affiliation(s)
- Kimberley Lothmann
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Jana Deitersen
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine INM-1, Research Centre Jülich, 52425, Jülich, Germany
| | - Katrin Amunts
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.,Institute of Neuroscience and Medicine INM-1, Research Centre Jülich, 52425, Jülich, Germany
| | - Christina Herold
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
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10
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Dentate Gyrus Sharp Waves, a Local Field Potential Correlate of Learning in the Dentate Gyrus of Mice. J Neurosci 2020; 40:7105-7118. [PMID: 32817247 DOI: 10.1523/jneurosci.2275-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/27/2020] [Accepted: 06/09/2020] [Indexed: 01/03/2023] Open
Abstract
The hippocampus plays an essential role in learning. Each of the three major hippocampal subfields, dentate gyrus (DG), CA3, and CA1, has a unique function in memory formation and consolidation, and also exhibit distinct local field potential (LFP) signatures during memory consolidation processes in non-rapid eye movement (NREM) sleep. The classic LFP events of the CA1 region, sharp-wave ripples (SWRs), are induced by CA3 activity and considered to be an electrophysiological biomarker for episodic memory. In LFP recordings along the dorsal CA1-DG axis from sleeping male mice, we detected and classified two types of LFP events in the DG: high-amplitude dentate spikes (DSs), and a novel event type whose current source density (CSD) signature resembled that seen during CA1 SWR, but which, most often, occurred independently of them. Because we hypothesize that this event type is similarly induced by CA3 activity, we refer to it as dentate sharp wave (DSW). We show that both DSWs and DSs differentially modulate the electrophysiological properties of SWR and multiunit activity (MUA). Following two hippocampus-dependent memory tasks, DSW occurrence rates, ripple frequencies, and ripple and sharp wave (SW) amplitudes were increased in both, while SWR occurrence rates in dorsal CA1 increased only after the spatial task. Our results suggest that DSWs, like SWRs, are induced by CA3 activity and that DSWs complement SWRs as a hippocampal LFP biomarker of memory consolidation.SIGNIFICANCE STATEMENT Awake experience is consolidated into long-term memories during sleep. Memory consolidation crucially depends on sharp-wave ripples (SWRs), which are local field potential (LFP) patterns in hippocampal CA1 that increase after learning. The dentate gyrus (DG) plays a central role in the process of memory formation, prompting us to cluster sharp waves (SWs) in the DG [dentate SWs (DSWs)] during sleep. We show that both DSW coupling to CA1 SWRs, and their occurrence rates, robustly increase after learning trials. Our results suggest that the DG is directly affected by memory consolidation processes. DSWs may thus complement SWRs as a sensitive electrophysiological biomarker of memory consolidation in mice.
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de la Prida LM. Potential factors influencing replay across CA1 during sharp-wave ripples. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190236. [PMID: 32248778 DOI: 10.1098/rstb.2019.0236] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sharp-wave ripples are complex neurophysiological events recorded along the trisynaptic hippocampal circuit (i.e. from CA3 to CA1 and the subiculum) during slow-wave sleep and awake states. They arise locally but scale brain-wide to the hippocampal target regions at cortical and subcortical structures. During these events, neuronal firing sequences are replayed retrospectively or prospectively and in the forward or reverse order as defined by experience. They could reflect either pre-configured firing sequences, learned sequences or an option space to inform subsequent decisions. How can different sequences arise during sharp-wave ripples? Emerging data suggest the hippocampal circuit is organized in different loops across the proximal (close to dentate gyrus) and distal (close to entorhinal cortex) axis. These data also disclose a so-far neglected laminar organization of the hippocampal output during sharp-wave events. Here, I discuss whether by incorporating cell-type-specific mechanisms converging on deep and superficial CA1 sublayers along the proximodistal axis, some novel factors influencing the organization of hippocampal sequences could be unveiled. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.
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