On mouse pups and their lactating dams: behavioral consequences of early exposure to oxazepam and interacting factors.

Behavioral analysis in animal models appears to be a valuable and sensitive tool for detecting subtle alterations in CNS function, which can be produced by early exposure to small perturbations of sensory experience, hormonal milieu, or exposure to psychotropic agents devoid of major teratogenic potential. Concerning anxiolytics, the more recent work in mice, which is here summarized, was carried out by putting the emphasis on changes in naturally occurring species-typical social responses as a function of early exposure to benzodiazepines. For adult females, on the behavior expressed during the early postpartum period, whereas for infant subjects, on the ontogenetic stage of the establishment of social bonding. Critical issues such as the choice of fostering procedure and rearing conditions are also addressed. Evidences of relationships between changes in social milieu taking place during early rearing-i.e., when dramatic transitions in the neurochemical target system occur- and the adult behavioral response to challenges with BDZ agents are presented. These data strengthen the notion that the modes of reaction of adult animals to the joint influence of physiological and environmental (stimulus) variables are under the influence of events in early ontogenesis. Therefore, a better understanding of the mechanisms-as unveiled by an appropriate use of drug tools-that mediate such a plasticity might have considerable psychobiological and clinical-therapeutical relevance.