CHANGES OF AUDITORY-EVOKED POTENTIALS IN RESPONSE TO BEHAVIORALLY MEANINGFUL TONES INDUCED BY ACUTE ETHANOL INTAKE IN ALTRICIAL NESTLINGS AT THE STAGE OF FORMATION OF NATURAL BEHAVIOR

Acute ethanol's influence on field L auditory-evoked potentials (AEP) was studied in 4-7-days-old altricial nestlings of the pied flycatcher. Nestlings were presented with behaviorally meaningful tone pips (2.0 and 5.0 kHz) and control tone pips (3.0 kHz). Ethanol ingestion was found to reduce the N1 amplitude and maturity index (MI) of the AEP in response to ''behavioral'' but not to control frequencies. This effect was first observed on day 5, when the nestlings' behavior became more complex (their eyes opened and defence behavior appeared), and when previously formed feeding behavior was undergoing modifications. The MI increase during the early postembryonic ontogeny was probably due to the selective involvement of neurons with newly formed behavioral specializations into the subserving of new behavioral patterns, while the decrease of the MI under alcohol was due to the depression of activity in these neurons.