[Involvement of the brain dopaminergic systems in the development of the MPTP-induced depressive state in rats].

Depressive state was produced in Wistar rats by repeated intraperitoneal administration of proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) inducing death of brain dopaminergic neurons. Weight loss and increase in REM-sleep rate during diurnal sleep were considered to be signs of the development of an experimental depressive state. During the development of the depressive state of rats, the MPTP-induced reorganization of the spectral power of electrical activity was observed in the terminal fields of the nigrostriatal, mesocortical, and mesolimbic dopaminergic systems, amygdala, and hippocampus. The most pronounced changes were revealed in the terminal field of the nigrostriatal system and hippocampus. The reorganization of the spectral power in the thetal and theta2 bands in the hippocampus and dopaminergic structures suggests the involvement of the hippocampus in producing changes in the emotional state during development of the MPTP-induced depressive syndrome.