The posterior insular cortex is necessary for the consolidation of tone fear conditioning

Neurobiol Learn Mem. 2021 Mar:179:107402. doi: 10.1016/j.nlm.2021.107402. Epub 2021 Feb 11.

Abstract

The insular cortex (IC) is notably implicated in emotional and cognitive processing; however, little is known regarding to what extent its two main subregions play functionally distinct roles on memory consolidation of conditioned fear tasks. Here we verified the effects of temporary functional inactivation of the anterior (aIC) and posterior IC (pIC) on contextual and tone fear memory. Rats received post-training bilateral infusions of the GABAA receptor agonist muscimol into either the aIC or pIC and were tested 48 and 72 h after the delay tone fear conditioning session to assess the background contextual (CFC) and tone (TFC) fear conditioning, respectively. Inactivation of the aIC during memory consolidation did not affect fear memory for CFC or TFC. On the other hand, post-training inactivation of the pIC impaired TFC but not CFC. Our findings indicate that the pIC is a necessary part of the neural circuitry related to the consolidation of cued-fear memories.

Keywords: Emotional memory; Fear conditioning; Fear memory; Insula; Muscimol; Rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiology*
  • Conditioning, Classical / drug effects
  • Conditioning, Classical / physiology*
  • Fear*
  • GABA-A Receptor Agonists / pharmacology
  • Memory Consolidation / drug effects
  • Memory Consolidation / physiology*
  • Muscimol / pharmacology
  • Rats

Substances

  • GABA-A Receptor Agonists
  • Muscimol