Specific Hippocampal Interneurons Shape Consolidation of Recognition Memory

Cell Rep. 2020 Aug 18;32(7):108046. doi: 10.1016/j.celrep.2020.108046.

Abstract

A complex array of inhibitory interneurons tightly controls hippocampal activity, but how such diversity specifically affects memory processes is not well understood. We find that a small subclass of type 1 cannabinoid receptor (CB1R)-expressing hippocampal interneurons determines episodic-like memory consolidation by linking dopamine D1 receptor (D1R) signaling to GABAergic transmission. Mice lacking CB1Rs in D1-positive cells (D1-CB1-KO) display impairment in long-term, but not short-term, novel object recognition memory (NOR). Re-expression of CB1Rs in hippocampal D1R-positive cells rescues this NOR deficit. Learning induces an enhancement of in vivo hippocampal long-term potentiation (LTP), which is absent in mutant mice. CB1R-mediated NOR and the associated LTP facilitation involve local control of GABAergic inhibition in a D1-dependent manner. This study reveals that hippocampal CB1R-/D1R-expressing interneurons control NOR memory, identifying a mechanism linking the diversity of hippocampal interneurons to specific behavioral outcomes.

Keywords: CB(1) receptor; D(1) receptor; GABA; dopamine; endocannabinoid system; hippocampus; interneurons; long-term potentiation; novel object recognition memory.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Hippocampus / physiology*
  • Male
  • Memory / physiology*
  • Mice
  • Recognition, Psychology / physiology*