5,7-dihydroxytryptamine lesions of the dorsal and median raphe nuclei interfere with lithium-induced conditioned gaping, but not conditioned taste avoidance, in rats.
Both the dorsal and median raphe nuclei of the midline brainstem region in rats were lesioned with the neurotoxin 5,7-dihydroxytryptamine. Rats were then surgically implanted with intraoral cannulas for fluid delivery and received a single conditioning trial in which 2-min saccharin infusion was followed by either lithium or saline administration. The conditioned gaping seen in the lithium-conditioned rats was significantly attenuated by raphe lesions, indicating that reduction of forebrain serotonin levels interferes with conditioned gaping. However, lesioned rats still expressed comparable conditioned taste avoidance as measured by both the 1- and 2-bottle consumption tests. These results parallel previous pharmacological findings indicating that reduction of serotonin activity interferes with conditioned gaping, but not conditioned taste avoidance.
Limebeer
Cheryl L
CL
Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada. climebeer@rogers.com
Parker
Linda A
LA
Fletcher
Paul J
PJ
D015116:5,7-Dihydroxytryptamine / Q000633:toxicity*; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal; D001923:Brain Chemistry / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D003891:Desipramine / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D005518:Food Preferences / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D011903:Raphe Nuclei / Q000033:anatomy & histology / Q000293:injuries* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage; D018490:Serotonin Agents / Q000633:toxicity*; D013649:Taste / Q000187:drug effects
D018759:Adrenergic Uptake Inhibitors; D018490:Serotonin Agents; D015116:5,7-Dihydroxytryptamine; D008094:Lithium; D012439:Saccharin; D003891:Desipramine