Nonretention of a visual conditioned heart-rate response under neocortical spreading depression.

Abstract

A DECELERATIVE HEART-RATE RESPONSE WAS CONDITIONED TO A 5-SEC LIGHT STIMULUS PAIRED WITH SHOCK IN RATS CHRONICALLY IMPLANTED FOR ELECTRICAL RECORDING AND KCL APPLICATION. SUBSEQUENT TO TRAINING RETENTION OF THE CARDIAC CR WAS TESTED UNDER NEOCORTICAL SPREADING DEPRESSION INDUCED WITH 25% KCL; IN EVERY INSTANCE PERCENTAGE OF HEART-RATE CR WAS NO MORE THAN THAT OCCURRING SPONTANEOUSLY IN NAIVE SS. RETENTION IN THE RECOVERED S WAS ESSENTIALLY UNIMPAIRED. NONRETENTION OF THE CARDIAC CR UNDER SPREADING DEPRESSION APPEARS AMENABLE TO 1 OF 2 MAJOR EXPLANATIONS: (1) THE CORTEX NORMALLY PLAYS A CRUCIAL ROLE IN HEART-RATE CONDITIONING, OR (2) DISRUPTIVE SUBCORTICAL EFFECTS OF "FUNCTIONAL DECORTICATION" ARE CRITICAL. (PsycINFO Database Record (c) 2006 APA, all rights reserved)