Mouse hippocampal CA1 VIP interneurons detect novelty in the environment and support recognition memory

Cell Rep. 2024 Apr 23;43(4):114115. doi: 10.1016/j.celrep.2024.114115. Epub 2024 Apr 11.

Abstract

In the CA1 hippocampus, vasoactive intestinal polypeptide-expressing interneurons (VIP-INs) play a prominent role in disinhibitory circuit motifs. However, the specific behavioral conditions that lead to circuit disinhibition remain uncertain. To investigate the behavioral relevance of VIP-IN activity, we employed wireless technologies allowing us to monitor and manipulate their function in freely behaving mice. Our findings reveal that, during spatial exploration in new environments, VIP-INs in the CA1 hippocampal region become highly active, facilitating the rapid encoding of novel spatial information. Remarkably, both VIP-INs and pyramidal neurons (PNs) exhibit increased activity when encountering novel changes in the environment, including context- and object-related alterations. Concurrently, somatostatin- and parvalbumin-expressing inhibitory populations show an inverse relationship with VIP-IN and PN activity, revealing circuit disinhibition that occurs on a timescale of seconds. Thus, VIP-IN-mediated disinhibition may constitute a crucial element in the rapid encoding of novelty and the acquisition of recognition memory.

Keywords: CP: Neuroscience.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CA1 Region, Hippocampal* / cytology
  • CA1 Region, Hippocampal* / metabolism
  • CA1 Region, Hippocampal* / physiology
  • Exploratory Behavior / physiology
  • Interneurons* / metabolism
  • Interneurons* / physiology
  • Male
  • Memory / physiology
  • Mice
  • Mice, Inbred C57BL
  • Parvalbumins / metabolism
  • Pyramidal Cells / metabolism
  • Pyramidal Cells / physiology
  • Recognition, Psychology* / physiology
  • Somatostatin / metabolism
  • Vasoactive Intestinal Peptide* / metabolism

Substances

  • Vasoactive Intestinal Peptide
  • Parvalbumins
  • Somatostatin