The medial entorhinal cortex (MEC) is a major center for spatial navigation and memory. We found that cannabinoid type 1 receptor-expressing GABAergic basket cells selectively innervated principal cells in layer II of the rat MEC that projected outside the hippocampus but avoided neighboring cells that give rise to the perforant pathway to the dentate gyrus. These results indicate that the organization of GABAergic microcircuits reflects the long-distance axonal targets of principal neurons.
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http://dx.doi.org/10.1038/nn.2570 | DOI Listing |
Nat Commun
January 2025
Department of Neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, China.
Successful navigation relies on reciprocal transformations between spatial representations in world-centered (allocentric) and self-centered (egocentric) frames of reference. The neural basis of allocentric spatial representations has been extensively investigated with grid, border, and head-direction cells in the medial entorhinal cortex (MEC) forming key components of a 'cognitive map'. Recently, egocentric spatial representations have also been identified in several brain regions, but evidence for the coexistence of neurons encoding spatial variables in each reference frame within MEC is so far lacking.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
College of Public Health, University of Kentucky, Lexington, KY, USA.
Background: Brain arteriolosclerosis (B-ASC) is a pathologic hallmark characterized by dysmorphic brain arteriolar wall thickening. B-ASC is a common finding at autopsy in aged persons - some degree of B-ASC is seen in >80% of brains beyond age 80 years - and is associated with cognitive impairment. Hypertension and diabetes are widely recognized as risk factors for B-ASC.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of Exeter, Exeter, Devon, United Kingdom.
Background: Huntington's disease (HD) is an autosomal dominant condition causing severe neurodegeneration in the striatum and the entorhinal cortex (EC). An epigenome wide association study of DNA methylation in HD by our group, identified potential hypomethylation at the PTGDS gene in the striatum. We aimed to validate this result through pyrosequencing, examining the locus in fine detail, and to assess the signal specificity by profiling multiple neurodegenerative diseases.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
LCBC, University of Oslo, Oslo, Norway.
Background: Grid cells are spatially modulated cells in the entorhinal cortex (EC) that fire in a hexagonally patterned grid which tiles the environment. These cells are assumed important in human spatial navigation. The EC is vulnerable to neurodegenerative processes in both normal aging and Alzheimer's disease and decline in grid cell function may be a key factor in understanding age-related navigational decline.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
NYU Grossman School of Medicine, New York, NY, USA.
Background: How tauopathy disrupts direct entorhinal cortex (EC) inputs to CA1 and their plasticity is understudied, despite its critical role in memory. Moreover, dysfunction of lateral EC (LEC) input is less clear, despite its relevance to early Alzheimer's disease pathogenesis. Here we examined how tau impacts long-term potentiation (LTP) of LEC→CA1 input in a transgenic model of tauopathy.
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