In:
Hippocampus, Wiley, Vol. 31, No. 1 ( 2021-01), p. 56-78
Kurzfassung:
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 mGluR 2/3 , GABAergic GABA A (including benzodiazepine binding sites), GABA B , dopaminergic D 1/5 and noradrenergic α 1 and α 2 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 GABA B . For example, striking higher densities of α 2 receptors were detected in the ventral DG, while the dorsal DG possesses higher numbers of kainate, NMDA, GABA A and D 1/5 receptors. CA1 dorsal and intermediate subdivisions showed higher AMPA, NMDA, mGluR 2/3 , GABA A , D 1/5 receptors, while kainate receptors are higher expressed in ventral CA1, and noradrenergic α 1 and α 2 receptors in the intermediate region of CA1. CA2 dorsal was distinguished by higher kainate, α 1 and α 2 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.
Materialart:
Online-Ressource
ISSN:
1050-9631
,
1098-1063
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2021
ZDB Id:
1498049-6
