Muscarinic, nicotinic and GABAergic receptor signaling differentially mediate fat-conditioned flavor preferences in rats.

Rats display conditioned flavor preferences (CFP) for fats. Previous studies demonstrated that whereas expression of an already-acquired corn oil (CO)-CFP was mildly reduced by dopamine (DA) D1, DA D2, NMDA or opioid receptor antagonists, the acquisition or learning of CO-CFP was eliminated by NMDA antagonists, and significantly reduced by DA D1 and D2, but not opioid antagonists. Previous studies of fructose-CFP demonstrated that muscarinic (scopolamine) and nicotinic (mecamylamine) cholinergic receptor antagonists and GABA (baclofen) receptor agonism reduced the expression of this acquired response, and that scopolamine, but not mecamylamine or baclofen eliminated the acquisition or learning of this response.

Baclofen differentially mediates fructose-conditioned flavor preference and quinine-conditioned flavor avoidance in rats.

Rats display both fructose-conditioned flavor preference (CFP) and quinine conditioned flavor avoidance (CFA). Dopamine (D1 and D2), muscarinic and nicotinic, but not NMDA or opioid receptor antagonists reduced fructose-CFP expression. Dopamine D1, dopamine D2, muscarinic or NMDA, but not opioid or nicotinic receptor antagonists reduced fructose-CFP acquisition.

Muscarinic and nicotinic cholinergic receptor antagonists differentially mediate acquisition of fructose-conditioned flavor preference and quinine-conditioned flavor avoidance in rats.

Rats display both conditioned flavor preference (CFP) for fructose, and conditioned flavor avoidance (CFA) following sweet adulteration with quinine. Previous pharmacological analyses revealed that fructose-CFP expression was significantly reduced by dopamine (DA) D1 or D2 antagonists, but not NMDA or opioid antagonists. Fructose-CFP acquisition was significantly reduced by DA D1, DA D2 or NMDA antagonists, but not opioid antagonists.