Lack of neuronal adaptive changes following chronic treatments in perinatally undernourished rats.

Reactivity of presynaptic dopaminergic and alpha 2-adrenoceptors following repeated stress or desipramine treatment was investigated by means of apomorphine (APO)- or clonidine (CLO)-induced hypoactivity, respectively, in adult rats undernourished at perinatal age. Under basal conditions, a comparable hypoactive response was observed in control and experimental animals following either APO or CLO administration. Chronic DMI or repeated immobilization sessions attenuated the hypoactivity elicited by APO or CLO in control animals; however, this effect was not observed in experimental rats. These findings demonstrate that deprived animals show impairment to produce neuronal adaptive changes in response to appropriate stimuli, which may account for the behavioral alterations attributed to early undernutrition.