The Posterior Insular Cortex is Necessary for the Consolidation of Tone Fear Conditioning

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 hours after the conditioning session to assess 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. HighlightsO_LIWe studied the role of the anterior (aIC) and posterior (pIC) insula in fear memory C_LIO_LIPost-training inactivation of aIC and pIC did not impact contextual fear conditioning C_LIO_LIThe pIC but not aIC is necessary for the consolidation of tone fear conditioning C_LI