Reduction of nicotine-induced hyperactivity by pCPA.

Spontaneous locomotion of female Wistar rats was measured in six to ten minute sessions in an automated tunnel maze consisting of a central arena and six radially symmetrical angled arms. Nicotine (0.2 mg/kg subcutaneous, 20-30 minutes pretest) increased total arm visit frequency, but intrasession habituation and number of repetitive arm visits in the first six choices were not affected. pCPA (300 mg/kg IP three days pretest) reduced arm-visit frequency in nicotine-, but not in saline-treated rats; it had no effect on intrasession habituation or number of repetitions in either treatment group. 5-HTP (50 mg/kg IP 90 minutes pretest) reduced arm entry frequency in saline-, nicotine-, and pCPA-treated groups. Possible reasons for this discrepancy are discussed.