Cholecystokinin, but not bombesin, has interoceptive sensory consequences like 1-h food deprivation.
A comparison of the interoceptive sensory consequences of cholecystokinin, bombesin, and 1-h food deprivation was conducted in rats. In two experiments, rats were first trained to use stimuli arising from different degrees of food deprivation (1 and 24 h or 1 and 4 h) as discriminative signals for shock, and were then tested for generalized control of discriminative responding (i.e., conditioned freezing) by cues arising from injection of 4 micrograms/kg (Experiment 1 only) and 8 micrograms/kg cholecystokinin (Experiment 1A only), 12 micrograms/kg bombesin (BBS), and isotonic saline, respectively. The effects of these peptides on food intake were also assessed. In both experiments, BBS and cholecystokinin (CCK) each suppressed feeding relative to saline; however, generalization of discriminative responding was obtained only following CCK. Generalization depended on prior learning about food deprivation cues--CCK had little effect on freezing in rats that showed weak discrimination performance (i.e., rats trained with 1- and 4-h deprivation cues). The results indicated that CCK but not BBS produces interoceptive cues like those occurring under 1-h food deprivation.
Purdue University, West Lafayette, IN 47907.
T L
TL
Davidson
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JC
Carretta
D000818:Animals; D001143:Arousal / Q000187:drug effects*; D001245:Association Learning / Q000187:drug effects*; D001839:Bombesin / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D004597:Electroshock; D005108:Extinction, Psychological / Q000187:drug effects; D005508:Food Deprivation; D005793:Generalization, Psychological / Q000187:drug effects; D006815:Hunger / Q000187:drug effects*; D008297:Male; D011340:Problem Solving / Q000187:drug effects; D051381:Rats; D012528:Satiety Response / Q000187:drug effects; D012844:Sincalide / Q000494:pharmacology*
D012844:Sincalide; D001839:Bombesin