[The effect of excess catecholamines on grooming in rats in postnatal ontogeny]

During the first month of postnatal life, studies have been made of the effect of L-DOPA on grooming in rat puppies. It was found that within the first hour after injection of the drug, its inhibitory effect increases in the course of ontogenetic development. In some of the animals, the increase in grooming was observed, whereas in other ones the effect was absent. Inhibition concerns both the number of grooming outbursts and the duration of rhythmic phase. These changes are associated with the decrease of afferent input to the central nervous system and with inhibition of the activity of pacemakers of rhythmic motor excitation.