Lesions of the amygdala central nucleus abolish lipoprivic-enhanced responding during oil-predicting conditioned stimuli.
T. L. Davidson, A. M. Altizer, S. C. Benoit, E. K. Walls, and T. L. Powley (1997) reported that rats show facilitated responding to conditioned stimuli (CSs) that predict oil, after administration of the lipoprivic agent, Na-2-mercaptoacetate (MA). This facilitation was blocked by vagal deafferentation. The present article extends that investigation to another structure, the amygdala central nucleus (CN). The CN receives inputs from dorsal vagal nuclei, and neurotoxic lesions of this nucleus are reported to abolish feeding in response to lipoprivic challenges. In Experiment 1, rats with ibotenic acid (IBO) lesions of the CN failed to show enhanced appetitive responding during oil-predicting CSs after administration of MA. Experiment 2 used a conditioned taste-aversion procedure to establish that rats with IBO lesions of the CN were able to discriminate the tastes of sucrose and peanut oil and had intact CS-US representations. It is concluded that the amygdala CN is a necessary structure for the detection of lipoprivic challenges.
Benoit
S C
SC
Department of Psychology, Purdue University, USA. benoits@email.uc.edu
Morell
J R
JR
Davidson
T L
TL
D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D001362:Avoidance Learning / Q000502:physiology*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000494:pharmacology; D007051:Ibotenic Acid / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D051381:Rats; D017207:Rats, Sprague-Dawley; D013864:Thioglycolates / Q000008:administration & dosage / Q000494:pharmacology
D018690:Excitatory Amino Acid Agonists; D013864:Thioglycolates; D007051:Ibotenic Acid; C017487:2-mercaptoacetate