RETROGRADE AMNESIA IN RATS PRODUCED BY HIPPOCAMPAL INJECTIONS OF POTASSIUM CHLORIDE - GRADIENT OF EFFECT AND RECOVERY

Injected potassium chloride (KC1) or physiological saline (Sal) into the posterior hippocampus of 90 male Sprague-Dawley albino anesthetized rats that had previously been exposed to conditioned emotional response (CER) training. In Exp. I, injections were given either 1, 3, 7, or 21 days after training. All tests were given 4 days after injections. In Exp. II, injections were given 1 day after training; tests were given either 4, 7, or 21 days after injections. Hippocampal EEG recorded after injections indicated that KC1 injections disrupted the CER at all training-to-injection intervals. In Exp. II, these injections disrupted the CER at injection-to-test intervals of 4 and 7 days. Recovery was evident, but incomplete, at 21 days. Sal injections did not disrupt the CER in either experiment. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.