Differential effects of short-and long-term antidepressant treatments on the food-induced place preference conditioning in rats.
The effect of antidepressant drugs (ADs) on the rewarding properties of food, given to food-deprived rats, was studied with a conditioned place preference paradigm. Repeated (once a day for 4 days) association of an initially non-preferred environment with the presentation of food resulted in development of an increased preferences for that environment. That effect was diminished when each conditioning session was preceded by administration of single doses of imipramine, desipramine, amitriptyline, mianserin and citalopram (short-term treatment). In contrast, long-term treatment (16 days) with the above ADs, as well as repeated (9) applications of electroconvulsive shock significantly enhanced the food-induced place preference conditioning. In a separate experiment it was also found that ADs, used as unconditioned stimuli, produced a conditioned aversion to the environment previously paired with administration of single doses of the drugs. The above findings are discussed in terms of the enhancement by prolonged antidepressant treatments of the brain reward mechanisms.
Papp
M.
M
Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland Correspondence: Department of Psychology, City of London Polytechnic, Old Castle Street, London E1 7NT, UK.