Abstract: | Behavioral effects of neurotensin administration into the nucleus accumbens were studied in rats with neurotoxic lesions of serotoninergic structures of the dorsal raphe nucleus or periaqueductal grey matter. Changes in recall of passive avoidance conditioned reactions and aftereffects of painful stimulation in the locomotor activity were studied in the open field and elevated plus-maze and T-maze tests. The toxin administration into the dorsal raphe nucleus did not impair the recall of the passive avoidance reactions, but enhanced the oppressive aftereffects of painful stimulation, which can specify the development of anxiety in rats. The toxin administration into the periaqueductal grey matter had an opposite effect, which can be considered as a manifestation of the panic state. Neurotensin weakened the above mentioned effects of the toxin and, depending on the evoked emotional disorders, produced the anxiolytic or antipanic effects. |