EFFECT OF CYPROHEPTADINE TREATMENT ON CONDITIONED AVOIDANCE-RESPONSE IN FEMALE RATS

1. The percentage of conditioned avoidance response was higher during proestrus compared to diestrus. 2. Cyproheptadine (CPH) significantly enhanced avoidance behavior during diestrus. 3. On the other hand, CPH treatment did not alter avoidance behavior during proestrus. 4. Serum progesterone and testosterone levels were determined at the end of 60 trials for acquisition of conditioned avoidance response after prolon ged (12-15 days) CPH treatment (0.5 mg/kg for 24 h per os (p.o.). 5. P rolonged CPH treatment lowered adrenal testosterone levels, and rats w ith impaired avoidance had higher testosterone and progesterone levels . 6. The results of this study indicate a positive role for CPH in the acquisition of avoidance response during diestrus, and a negative eff ect of progesterone and adrenal testosterone on the avoidance response . Copyright (C) 1996 Elsevier Science Inc.