Teratopsychogenetic effects apparently produced by nonphysiological neurotransmitter concentrations during brain differentiation.

In male rats treated with pargyline, reserpine or pyridostigmine during neonatal life significant permanent changes of sexual behaviour and conditioned learning behaviour were observed in juvenile and/or adult life. Male sexual activity and learning capacity were permanently decreased in neonatally pargyline- or reserpine-treated animals, but permanently increased in neonatally pyridostigmine-treated rats. These findings suggest that nonphysiological concentrations and/or turnover rates of neurotransmitters, if produced during a critical period of brain differentiation, are able to induce lifelond effective behavioural changes, i.e. teratopsychogenetic effects.