CB2 cannabinoid receptor knockout in mice impairs contextual long-term memory and enhances spatial working memory

Yong Li, Jimok Kim

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Neurocognitive effects of cannabinoids have been extensively studied with a focus on CB1 cannabinoid receptors because CB1 receptors have been considered the major cannabinoid receptor in the nervous system. However, recent discoveries of CB2 cannabinoid receptors in the brain demand accurate determination of whether and how CB2 receptors are involved in the cognitive effects of cannabinoids. CB2 cannabinoid receptors are primarily involved in immune functions, but also implicated in psychiatric disorders such as schizophrenia and depression. Here, we examined the effects of CB2 receptor knockout in mice on memory to determine the roles of CB2 receptors in modulating cognitive function. Behavioral assays revealed that hippocampus-dependent, long-term contextual fear memory was impaired whereas hippocampus-independent, cued fear memory was normal in CB2 receptor knockout mice. These mice also displayed enhanced spatial working memory when tested in a Y-maze. Motor activity and anxiety of CB2 receptor knockout mice were intact when assessed in an open field arena and an elevated zero maze. In contrast to the knockout of CB2 receptors, acute blockade of CB2 receptors by AM603 in C57BL/6J mice had no effect on memory, motor activity, or anxiety. Our results suggest that CB2 cannabinoid receptors play diverse roles in regulating memory depending on memory types and/or brain areas.

Original languageEnglish (US)
Article number9817089
JournalNeural Plasticity
Volume2016
DOIs
StatePublished - Jan 1 2016

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Cannabinoid Receptor CB2
Long-Term Memory
Short-Term Memory
Knockout Mice
Cannabinoid Receptor CB1
Cannabinoids
Fear
Hippocampus
Motor Activity
Anxiety
Spatial Memory
Cannabinoid Receptors
Brain
Inbred C57BL Mouse
Cognition
Nervous System
Psychiatry
Schizophrenia

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology

Cite this

CB2 cannabinoid receptor knockout in mice impairs contextual long-term memory and enhances spatial working memory. / Li, Yong; Kim, Jimok.

In: Neural Plasticity, Vol. 2016, 9817089, 01.01.2016.

Research output: Contribution to journalArticle

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