Dopaminergic agonists and conditioned avoidance response in normoxic or hypoxic rats.

The actions of four dopaminergic agonists (apomorphine, bromocriptine, amantadine, piribedil) on a conditioned avoidance response were studied in normoxic or hypobaric hypoxic rats. Low doses of agonists have no effects on normoxia, but induce an antihypoxic protection (improvement of learning both in normoxia and hypobaric hypoxia. The possibility of an antihypoxic property induced by dopaminergic post-synaptic receptors stimulation is discussed and seems to be the main receptors stimulation is discussed and seems to be the main phenomenon while action or other non-specific sites seems to be responsible for the high dose-induced impairment of learning and of resistance to hypoxia.