Effect of temporary septal dysfunction on conditioning and performance of fear responses in rats.

Abstract

Determined the effect of septal dysfunction on fear conditioning apart from performance effects such as response perseveration and decrement in freezing. 9 male Long-Evans rats were subjected to tone-shock pairings while in a state of temporary septal dysfunction resulting from injection of procaine into the septum via chronically implanted cannulae. 10 nonoperated, 6 cannula-only, 8 saline-injected, and 6 delayed procaine-injected Ss were controls. When tested for conditioned suppression in the normal state, Ss that had been conditioned immediately following procaine injection suppressed significantly less than did controls, indicating that septal dysfunction impaired conditioning. The deficit could be partially responsible for previously reported effects of septal damage on passive avoidance. Procaine injection also temporarily reduced freezing elicited by the CS, whereas electrolytic septal damage caused a permanent deficit in freezing behavior. (PsycINFO Database Record (c) 2006 APA, all rights reserved)