CHANGES IN SOCIO-EMOTIONAL BEHAVIOR UNDER IMIPRAMINE TREATMENT IN NORMAL AND AMYGDALO-HYPOTHALAMIC DOGS

The effects of imipramine on learned social responses were examined in ten dogs with dorsomedial amygdalar lesions and/or lateral hypothalamic lesions. Six of the ten dogs were also tested pre- operatively. The social responses were instrumentally conditioned using social interaction with the experimenter as reinforcement (petting and verbal reassurance). In the non-lesioned dogs imipramine treatment produced a dose-dependent deterioration of performance during drug administration followed by a long-term amelioration of performance. In the lesioned dogs imipramine produced various changes in perfor- mance depending on the pretreatment level of responding. When the pretreatment level of performance was high drug administration resulted in a long-term deterioration, and when performance was poor imi- pramine produced a continuous and long-term increase. It is suggested that imipramine facilitates the recovery of performance, but suppresses well-performed responses.