Parabrachial nucleus lesions block taste and attenuate flavor preference and aversion conditioning in rats.
Rats with ibotenic acid lesions of the parabrachial nucleus (PBN) failed to learn a taste aversion induced by lithium chloride (LiCl) toxicosis. The same rats also did not learn to prefer a taste that was paired with intragastric (IG) carbohydrate infusions during 22 hr/day trials. The PBN-lesioned rats did learn to prefer a flavor (odor + taste) paired with the IG carbohydrate infusions over a different flavor paired with IG water. The PBN-lesioned rats also learned to avoid a flavor paired with IG LiCl infusions during 22 hr/day trials. The flavor preference and aversion, however, were less pronounced than those displayed by control rats. These data indicate that the PBN is essential for forming orosensory-viscerosensory associations when taste is the primary cue but is less critical when more complex flavor cues are available.
Sclafani
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A
Department of Psychology, Brooklyn College and The Graduate School, City University of New York, 11210-2889, USA. asclafani@gc.cuny.edu
Azzara
A V
AV
Touzani
K
K
Grigson
P S
PS
Norgren
R
R
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001362:Avoidance Learning / Q000502:physiology*; D003214:Conditioning, Classical; D005518:Food Preferences; D008297:Male; D009434:Neural Pathways; D011149:Pons / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012903:Smell / Q000502:physiology*; D017552:Solitary Nucleus / Q000473:pathology / Q000502:physiology*; D013649:Taste / Q000502:physiology*