Entorhinal cortical innervation of parvalbumin-containing neurons (Basket and Chandelier cells) in the rat Ammon's horn.
Physiological data suggest that in the CA1-CA3 hippocampal areas of rats, entorhinal cortical efferents directly influence the activity of interneurons, in addition to pyramidal cells. To verify this hypothesis, the following experiments were performed: 1) light microscopic double-immunostaining for parvalbumin and the anterograde tracer Phaseolus vulgaris-leucoagglutinin injected into the entorhinal cortex; 2) light and electron microscopic analysis of cleaved spectrin-immunostained (i.e., degenerating axons and boutons) hippocampal sections following entorhinal cortex lesion; and 3) an electron microscopic study of parvalbumin-immunostained hippocampal sections after entorhinal cortex lesion. The results demonstrate that in the stratum lacunosum-moleculare of the CA1 and CA3 regions, entorhinal cortical axons form asymmetric synaptic contacts on parvalbumin-containing dendritic shafts. In the stratum lacunosum-moleculare, parvalbumin-immunoreactive dendrites represent processes of GABAergic, inhibitory basket and chandelier cells; these interneurons innervate the perisomatic area and axon initial segments of pyramidal cells, respectively. A feed-forward activation of these neurons by the entorhinal input may explain the strong, short-latency inhibition of pyramidal cells.
Kiss
J
J
Joint Research Organization of the Hungarian Academy of Sciences, Budapest, Hungary.
Buzsaki
G
G
Morrow
J S
JS
Glantz
S B
SB
Leranth
C
C
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D018728:Entorhinal Cortex / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007150:Immunohistochemistry; D007395:Interneurons / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000502:physiology; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010320:Parvalbumins / Q000378:metabolism*; D010835:Phytohemagglutinins; D017966:Pyramidal Cells / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013049:Spectrin / Q000378:metabolism; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure
D010320:Parvalbumins; D010835:Phytohemagglutinins; C100156:leukoagglutinins, plants; D013049:Spectrin