L-DOPA REVERSES CASTRATION-INDUCED DISRUPTION OF DISHABITUATION RESPONSES TO FEMALE CHEMICAL CUES IN MALE-RATS

In the present experiment, habituation/dishabituation behavioral tests were conducted to measure discriminatory olfactory recognition respon ses to chemical cues among control, castrated, and castrated + L-3,4-d ihydroxyphenylalanine (L-DOPA)-treated male rats. Castration produced a disruption of dishabituation responses to female urine, and this eff ect was reversed by treatment with L-DOPA. In the posterior olfactory bulb, 3,4-dihydroxyphenlacetic acid (DOPAC) levels were significantly increased in L-DOPA-treated animals compared with the vehicle-treated control and castrated groups. No significant differences in olfactory bulb norepinephrine or dopamine concentrations among the three treatme nt groups were obtained. The restoration of behavioral dishabituation responses following L-DOPA treatment suggests that the catecholaminerg ic system of the olfactory bulb may play a critical role in the recogn ition and possibly attractions for or preferences to female chemical c ues.