Premium
Area CA3 interneurons receive two spatially segregated mossy fiber inputs
Author(s) -
Cosgrove Kathleen E.,
Galván Emilio J.,
Meriney Stephen D.,
Barrionuevo Germán
Publication year - 2010
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.20713
Subject(s) - neuroscience , excitatory postsynaptic potential , inhibitory postsynaptic potential , perforant path , interneuron , dentate gyrus , biology , chemistry , central nervous system
Area CA3 receives two extrinsic excitatory inputs, the mossy fibers (MF), and the perforant path (PP). Interneurons with somata in str. lacunosum moleculare (L‐M) of CA3 modulate the influence of the MF and PP on pyramidal cell activity by providing strong feed‐forward inhibitory influence to pyramidal cells. Here we report that L‐M interneurons receive two separate MF inputs, one to the dorsal dendrites from the suprapyramidal blade of the dentate gyrus (MF SDG ), and a second to ventral dendrites from the str. lucidum (MF SL ). Responses elicited from MF SDG and MF SL stimulation sites have strong paired‐pulse facilitation, similar DCG‐IV sensitivity, amplitude, and decay kinetics but target spatially segregated domains on the interneuron dendrites. These data demonstrate that certain interneuron subtypes are entrained by two convergent MF inputs to spatially separated regions of the dendritic tree. This anatomical arrangement could make these interneurons considerably more responsive to the excitatory drive from dentate granule cells. Furthermore, temporal summation is linear or slightly sublinear between PP and MF SL but supralinear between PP and MF SDG . This specific boosting of the excitatory drive to interneurons from the SDG location may indicate that L‐M interneurons could be specifically involved in the processing of the associational component of the recognition memory. © 2009 Wiley‐Liss, Inc.