scholarly journals Potential factors influencing replay across CA1 during sharp-wave ripples

2020 ◽  
Vol 375 (1799) ◽  
pp. 20190236 ◽  
Author(s):  
Liset M. de la Prida
Keyword(s):  
Entorhinal Cortex ◽  
Slow Wave Sleep ◽  
Neuronal Firing ◽  
Cell Type ◽  
Subcortical Structures ◽  
Laminar Organization ◽  
Sharp Wave ◽  
Factors Influencing ◽  
Cell Type Specific ◽  
Potential Factors

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’.

scholarly journals Laminar Organization of the Entorhinal Cortex in Macaque Monkeys Based on Cell-Type-Specific Markers and Connectivity

2021 ◽  
Vol 15 ◽  
Author(s):  
Shinya Ohara ◽  
Rintaro Yoshino ◽  
Kei Kimura ◽  
Taichi Kawamura ◽  
Soshi Tanabe ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Entorhinal Cortex ◽  
Critical Role ◽  
Cell Protein ◽  
Cell Type ◽  
Laminar Organization ◽  
Macaque Monkeys ◽  
Genetic Tools ◽  
Cell Type Specific ◽  
Layer V

The entorhinal cortex (EC) is a major gateway between the hippocampus and telencephalic structures, and plays a critical role in memory and navigation. Through the use of various molecular markers and genetic tools, neuron types constituting EC are well studied in rodents, and their layer-dependent distributions, connections, and functions have also been characterized. In primates, however, such cell-type-specific understandings are lagging. To bridge the gap between rodents and primates, here we provide the first cell-type-based global map of EC in macaque monkeys. The laminar organization of the monkey EC was systematically examined and compared with that of the rodent EC by using immunohistochemistry for molecular markers which have been well characterized in the rodent EC: reelin, calbindin, and Purkinje cell protein 4 (PCP4). We further employed retrograde neuron labeling from the nucleus accumbens and amygdala to identify the EC output layer. This cell-type-based approach enabled us to apply the latest laminar definition of rodent EC to monkeys. Based on the similarity of the laminar organization, the monkey EC can be divided into two subdivisions: rostral and caudal EC. These subdivisions likely correspond to the lateral and medial EC in rodents, respectively. In addition, we found an overall absence of a clear laminar arrangement of layer V neurons in the rostral EC, unlike rodents. The cell-type-based architectural map provided in this study will accelerate the application of genetic tools in monkeys for better understanding of the role of EC in memory and navigation.

scholarly journals Target-specific M1 inputs to infragranular S1 pyramidal neurons

2016 ◽  
Vol 116 (3) ◽  
pp. 1261-1274 ◽  
Author(s):  
Amanda K. Kinnischtzke ◽  
Erika E. Fanselow ◽  
Daniel J. Simons
Keyword(s):  
Primary Motor Cortex ◽  
Pyramidal Neurons ◽  
Projection Neurons ◽  
Cell Type ◽  
Intrinsic Properties ◽  
Subcortical Structures ◽  
Medial Nucleus ◽  
Cell Type Specific ◽  
Posterior Medial Nucleus

The functional role of input from the primary motor cortex (M1) to primary somatosensory cortex (S1) is unclear; one key to understanding this pathway may lie in elucidating the cell-type specific microcircuits that connect S1 and M1. Recently, we discovered that a subset of pyramidal neurons in the infragranular layers of S1 receive especially strong input from M1 (Kinnischtzke AK, Simons DJ, Fanselow EE. Cereb Cortex 24: 2237–2248, 2014), suggesting that M1 may affect specific classes of pyramidal neurons differently. Here, using combined optogenetic and retrograde labeling approaches in the mouse, we examined the strengths of M1 inputs to five classes of infragranular S1 neurons categorized by their projections to particular cortical and subcortical targets. We found that the magnitude of M1 synaptic input to S1 pyramidal neurons varies greatly depending on the projection target of the postsynaptic neuron. Of the populations examined, M1-projecting corticocortical neurons in L6 received the strongest M1 inputs, whereas ventral posterior medial nucleus-projecting corticothalamic neurons, also located in L6, received the weakest. Each population also possessed distinct intrinsic properties. The results suggest that M1 differentially engages specific classes of S1 projection neurons, thereby regulating the motor-related influence S1 exerts over subcortical structures.

scholarly journals Analysis of Excitatory Microcircuitry in the Medial Entorhinal Cortex Reveals Cell-Type-Specific Differences

Neuron ◽  
2010 ◽  
Vol 68 (6) ◽  
pp. 1059-1066 ◽  
Author(s):  
Prateep Beed ◽  
Michael H.K. Bendels ◽  
Hauke F. Wiegand ◽  
Christian Leibold ◽  
Friedrich W. Johenning ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Cell Type ◽  
Medial Entorhinal Cortex ◽  
Cell Type Specific

scholarly journals Cell-Type Specific Phase Precession in Layer II of the Medial Entorhinal Cortex

2016 ◽  
Vol 36 (7) ◽  
pp. 2283-2288 ◽  
Author(s):  
Eric T. Reifenstein ◽  
Christian L. Ebbesen ◽  
Qiusong Tang ◽  
Michael Brecht ◽  
Susanne Schreiber ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Cell Type ◽  
Medial Entorhinal Cortex ◽  
Phase Precession ◽  
Cell Type Specific ◽  
Specific Phase

scholarly journals Sex-stratified single-cell RNA-Seq analysis identifies sex-specific and cell type-specific transcriptional responses in Alzheimer’s disease across two brain regions.

2021 ◽  
Author(s):  
Stella Belonwu ◽  
Yaqiao Li ◽  
Daniel Bunis ◽  
Arjun Rao ◽  
Caroline Warly Solsberg ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Single Cell ◽  
Entorhinal Cortex ◽  
Neurodegenerative Disorder ◽  
Brain Regions ◽  
Specific Gene ◽  
Cell Type ◽  
Transcriptional Responses ◽  
Cell Type Specific

Abstract Alzheimer’s disease (AD) is a pervasive neurodegenerative disorder that disproportionately affects women. Since neural anatomy and disease pathophysiology differ by sex, investigating sex-specific mechanisms in AD pathophysiology can inform new therapeutic approaches for both sexes. Here, we utilized nearly 74,000 cells from human prefrontal and entorhinal cortex samples from the first two publicly available single-cell RNA sequencing AD datasets to study cell type-specific sex-stratified transcriptomic perturbations in AD. Our examination at the single-cell level revealed that sex-specific gene and pathway differences in AD were most prominently observed in glial cells of the prefrontal cortex. In the entorhinal cortex, we observed the same genes and pathways to be perturbed in opposing directions between sexes in AD relative to healthy state. Our findings contribute to growing evidence of sex differences in AD-related transcriptomic changes, which can fuel the development of therapies that may prove more effective at reversing AD pathophysiology.

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