[The participation of the brain dopamine D1 and D2 receptors in the process of the development of depression induced by social confrontations in mice].

Brain D1 and D2 receptors were studied in male mice with repeated experience of social defeats in daily intermale aggressive confrontations inducing development of experimental depression. Groups of animals were studied after 10 (T10 losers) and 20 (T20 losers) days of agonistic confrontations. Mice after 5 days of individual housing were used as a control group. In the experimental groups D1/D2 antagonist cisfluphentixol (0.2 mg/kg) did not affect the communicative behavior in the partition test that estimated behavioral reactivity of a male to another one. Selective D2 antagonist sulpiride (20 mg/kg), however, decreased these reactions in the control group and, in particular, in T10 losers but was ineffective in T20 losers. Both antagonists changed behavior in Porsolt's test of the control mice and, to a greater extent, of T10 losers but failed to change it in T20 losers. Decrease in Bmax in nucleus accumbens and increase in Kd in amygdala were revealed in T20 losers with [3H]-SCH 23390 binding assay. The obtained evidence shows that development of DISC is accompanied by D1 and D2 receptor sensitivity changes. Analysis of data suggests the specific participation of D1 receptors of the mesolimbic dopaminergic system at the stage of developed DISC.