Synthesis of proteins in the critical periods of early postnatal ontogenesis: its role in the formation of intraspecies aggressive behavior of rats.

The significance of the synthesis of the protein in the brain for the formation of intraspecies aggressive behavior of isolated males in early postnatal ontogenesis, under the influence of social contacts, was revealed in experiments on 200 mongrel rats. Chronic administration of cycloheximide (0.5 mg/kg; intraperitoneally), a protein synthesis blocker at the stage of translation, to infant rats from the 15th to the 30th postnatal days, prior to daily three-hour sessions of contacts between them, disrupted the formation of intraspecies aggressive behavior. This was manifested at adult age by their hyperaggressivity and by changes in the proportions of various reactions in the integral act of aggressive behavior.