Domperidone interferes with conditioned disgust reactions but not taste avoidance evoked by a LiCl-paired taste in infant rats.
Rats exhibit taste avoidance and conditioned disgust reactions when stimulated with a tastant paired with lithium chloride (LiCl). Lithium-mediated activation of chemoreceptor nuclei at the brainstem appears to determine the acquisition of conditioned taste aversion (CTA) in adult rodents. Domperidone (DOM), an anti-emetic drug that does not cross the blood-brain barrier, was employed to analyze mechanisms underlying LiCl-mediated CTA in infant rats. On postnatal day 13 animals were given DOM followed by a pairing between intraoral saccharin and LiCl. Saccharin consumption at testing was lower in lithium-treated pups than in controls. DOM did not interfere with this LiCl-mediated taste avoidance but significantly decreased LiCl-mediated disgust reactions (head-shaking and wall climbing). Activation of the emetic system of the brainstem does not seem necessary for the acquisition of LiCl-mediated conditioned taste avoidance. Yet, these centers seem to be involved in the palatability shift resulting from taste-LiCl pairings. These results indicate an early dissociation between conditioned disgust reactions and conditioned taste avoidance.
Pautassi
Ricardo Marcos
RM
Center for Developmental Psychobiology Binghamton University Binghamton, NY 13902-6000, USA. pautassi@binghamton.edu
Arias
Carlos
C
Molina
Juan Carlos
JC
Spear
Norman
N
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D000932:Antiemetics / Q000008:administration & dosage / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects*; D001812:Blood-Brain Barrier / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects*; D004294:Domperidone / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D018021:Lithium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013649:Taste / Q000187:drug effects*
D000276:Adjuvants, Immunologic; D000932:Antiemetics; D004294:Domperidone; D018021:Lithium Chloride