On the formation of gamma-coherent cell assemblies by oriens lacunosum-moleculare interneurons in the hippocampus

Document Type

Article

Publication Date

8-14-2007

Abstract

Gamma frequency (30-80 Hz) network oscillations have been observed in the hippocampus during several behavioral paradigms in which they are often modulated by a theta frequency (4-12 Hz) oscillation. Interneurons of the hippocampus have been shown to be crucially involved in rhythms generation, and several subtypes with distinct anatomy and physiology have been described. In particular, the oriens lacunosum-moleculare (O-LM) interneurons were shown to synapse on distal apical dendrites of pyramidal cells and to spike preferentially at theta frequency, even in the presence of gamma-field oscillations. O-LM cells have also recently been shown to present higher axonal ramification in the longitudinal axis of the hippocampus. By using a hippocampal network model composed of pyramidal cells and two types of interneurons (O-LM and basket cells), we show here that the O-LM interneurons lead to gamma coherence between anatomically distinct cell modules. We thus propose that this could be a mechanism for coupling longitudinally distant cells excited by entorhinal cortex inputs into gamma-coherent assemblies. © 2007 by The National Academy of Sciences of the USA.

Identifier

34548088374 (Scopus)

Publication Title

Proceedings of the National Academy of Sciences of the United States of America

External Full Text Location

https://doi.org/10.1073/pnas.0705708104

ISSN

00278424

PubMed ID

17679692

First Page

13490

Last Page

13495

Issue

33

Volume

104

Grant

R01NS046058

Fund Ref

National Institute of Neurological Disorders and Stroke

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