Parvalbumin Interneurons of Hippocampus Tune Population Activity at Theta Frequency.

TitleParvalbumin Interneurons of Hippocampus Tune Population Activity at Theta Frequency.
Publication TypeJournal Article
Year of Publication2015
AuthorsAmilhon B, Huh CYL, Manseau F, Ducharme G, Nichol H, Adamantidis A, Williams S
JournalNeuron
Volume86
Issue5
Pagination1277-89
Date Published2015 Jun 03
ISSN1097-4199
Abstract

Hippocampal theta rhythm arises from a combination of recently described intrinsic theta oscillators and inputs from multiple brain areas. Interneurons expressing the markers parvalbumin (PV) and somatostatin (SOM) are leading candidates to participate in intrinsic rhythm generation and principal cell (PC) coordination in distal CA1 and subiculum. We tested their involvement by optogenetically activating and silencing PV or SOM interneurons in an intact hippocampus preparation that preserves intrinsic connections and oscillates spontaneously at theta frequencies. Despite evidence suggesting that SOM interneurons are crucial for theta, optogenetic manipulation of these interneurons modestly influenced theta rhythm. However, SOM interneurons were able to strongly modulate temporoammonic inputs. In contrast, activation of PV interneurons powerfully controlled PC network and rhythm generation optimally at 8 Hz, while continuously silencing them disrupted theta. Our results thus demonstrate a pivotal role of PV but not SOM interneurons for PC synchronization and the emergence of intrinsic hippocampal theta.

DOI10.1016/j.neuron.2015.05.027
Alternate JournalNeuron
PubMed ID26050044