Avoidance behaviour peculiarities induced by chronic treatment with L-DOPA in the neonatal period.

The aim of the research was to observe the effects of chronic treatment with L-DOPA in the neonatal period on reactivity in avoidance situations, the sympatheticoadrenal system being known to be constantly involved in the response to stress. At 3 weeks from birth the experimental group (52 chronically L-DOPA injected animals) was tested for the unconditioned avoidance behaviour (light-avoidance) limits, the capacity for learning and retaining a noxious significance in comparison to two control groups (53 animals injected with distilled water and 53 free of any such stress). The animals injected with L-DOPA since birth were significantly less than controls able to recall the noxioux significance they had trained on a single session and they extinguished eariler than controls did the conditioned passive avoidance response. The results are discussed from the point of view of the neurohormonal influence involved in setting up the specific avoidance phenotype.