Relation of consummatory responses and preabsorptive insulin release to palatability and learned taste aversions

In 6 experiments with 68 male Sprague-Dawley rats, the oral stimulation arising from food in the mouth produced a stereotyped sequence of ingestive consummatory responses and a rapid release of insulin prior to the absorption of nutrients into the blood. Conversely, when noxious taste stimuli were infused into the mouth, a different, aversive set of consummatory responses was evoked, and no insulin was released. These experiments demonstrate that pairing a sapid taste solution with LiCl reversed the consummatory response sequence to subsequent presentations of that taste from ingestion to aversion and abolished the preabsorptive release of insulin to that taste; this indicated an experience-produced shift in the palatability of the taste. It was further shown that a palatable but categorically noncaloric taste elicited behavioral ingestion but no insulin release. It is concluded that separate but related control systems operate to produce consummatory behavior and ingestive neuroendocrine responses. (64 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).