The 5-HT1A agonist 8-OH-DPAT dose-dependently interferes with the establishment and the expression of lithium-induced conditioned rejection reactions in rats.
BACKGROUND
The present experiments evaluated the potential of the 5-HT(1A )agonist, 8-OH-DPAT (DPAT), which reduces serotonin availability, to interfere with both the establishment and with the expression of lithium-induced conditioned rejection reactions (experiment 1) and lithium-induced taste avoidance (experiment 2). OBJECTIVES. To determine the effect of reduced serotonin availability on conditioned rejection reactions, a rat model of nausea.


METHODS
Rats were injected with 8-OH-DPAT [at doses of 0.0 (saline), 0.01 or 0.1 mg/kg, SC] 30 min prior to exposure to 0.1% saccharin solution by intra-oral infusion (experiment 1) or by bottle presentation (experiment 2). Immediately following saccharin exposure, rats were injected with 20 ml/kg lithium chloride (0.15 M) or 20 ml/kg saline solution. On each of three test trials, rats were injected with DPAT [0.0 (saline), 0.01 and 0.1 mg/kg, SC; counterbalanced order], 30 min prior to exposure to saccharin solution by intra-oral infusion (experiment 1) or by a two-bottle test (experiment 2: saccharin and water).


RESULTS
DPAT interfered with both the establishment (at a dose of 0.1 mg/kg, SC) and with the expression (at doses of 0.01 and 0.1 mg/kg, SC) of lithium-induced conditioned rejection reactions; however, DPAT did not modulate taste avoidance in a consumption test.


CONCLUSIONS
These results indicate that conditioned rejection reactions, but not taste avoidance, can be attenuated by the anti-emetic agent, 8-OH-DPAT.
Limebeer
Cheryl L
CL
Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada.
Parker
Linda A
LA
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D002755:Choice Behavior / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D009325:Nausea / Q000139:chemically induced / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013649:Taste / Q000187:drug effects
D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D008094:Lithium