Scopolamine injected into the rat amygdala impairs working memory in the double Y-maze.
Recent neurochemical results suggest the hypothesis that the nucleus basalis magnocellularis (nbm) cholinergic projection to the amygdala may play a role in memory. The present study investigated the effects of intra-amygdaloid injections of the cholinergic antagonist scopolamine on working and reference memory in the double Y-maze. Rats were pretrained until working and reference memory choice accuracy stabilized to a criterion of > or = 86% correct. Bilateral cannulae were then surgically implanted in the basolateral amygdaloid complex. Rats (n = 9) received scopolamine in doses of 8.0, 24.0, and 72.0 micrograms/0.5 microliter and saline (0.5 microliter) in a counterbalanced order with retraining to criterion between injections. Intra-amygdaloid scopolamine produced a dose-dependent and differential impairment of working and reference memory. A dose of 24.0 micrograms impaired working memory without significantly affecting reference memory; doses of 8.0 micrograms and 72.0 micrograms affected neither and both types of memory, respectively. Results implicate amygdaloid acetylcholine in memory.
Ingles
J L
JL
Department of Psychology, Queen's University, Kingston, Ontario, Canada.
Beninger
R J
RJ
Jhamandas
K
K
Boegman
R J
RJ
D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006185:Habituation, Psychophysiologic; D007858:Learning; D008297:Male; D008568:Memory / Q000187:drug effects*; D008845:Microinjections; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012601:Scopolamine / Q000008:administration & dosage / Q000494:pharmacology*
D012601:Scopolamine