Social isolation and cohabitation with haloperidol-treated partners: effect on density of striatal dopamine D2 receptors in the developing rat brain.

The influence of the social environment on striatal dopamine D2 receptor density in the developing rat brain was investigated. Social isolation of rats from 20 to 60 days of age was associated with a decrease in the density of striatal dopamine receptors. Daily handling of the animals did not attenuate this effect. Chronic haloperidol treatment increased striatal dopamine receptor density to normal control values. Cohabitation with haloperidol-treated rats from 20 to 60 days of age was also associated with a decrease in the density of striatal dopamine D2 receptors in nondrugged animals similar to that seen in animals housed in isolation. The contribution of early life experiences to the development of normal receptor functioning is discussed.