Convergence of excitatory and inhibitory inputs onto CCK‐containing basket cells in the CA1 area of the rat hippocampus

• DOI: 10.1111/j.1460-9568.2004.03225.x
• Publication Date: 2004-03-11T10:27:16Z
• Authors: Ferenc Mátyás; Tamás F. Freund; Attila I. Gulyás
• Keywords: Male; 0301 basic medicine; Afferent Pathways; 0303 health sciences; 03 medical and health sciences; Synapses; Animals; Rats, Wistar; Cholecystokinin; Hippocampus; Rats

Abstract The number and distribution of excitatory inhibitory inputs affect the integrative properties neurons. These parameters have been studied recently for several hippocampal neuron populations. Besides parvalbumin‐ (PV) containing cells that include basket axo‐axonic cells, cholecystokinin (CCK)‐containing interneurons also form a cell population with distinct from PV cells. Here, at light microscopic level, we reconstructed entire dendritic tree CCK‐immunoreactive (IR) to describe their geometry, total length laminar dendrites. This was followed by an electron analysis serial ultrathin sections immunostained against γ‐aminobutyric acid, estimate density synapses on somata, axon initial segments different subclasses CCK‐IR has average 6300 µm penetrates all layers. At CCK receive 80–230 per 100 µm. ratio is relatively high (35%) increases towards soma (83%). numbers converging onto are ∼ 8200. Comparison two, neurochemically reveals CCK‐containing much less synaptic input than cells; however, relative weight inhibition higher Additional differences in anatomical physiological predict under more diverse, elaborate control thus function two populations must be different.