[Effect of ethanol on components of the nonspecific startle reaction in man]

The components of the startle reaction (SR) (reactions of nonspecific motor activation, the wink reflex and reflectory alleviation of motoneurones) were utilized as indices of the functional status of the midbrain system of cerebral nonspecific activation. Healthy subjects and chronic alcoholics in the abstinence period were examined. The patients exhibited significantly lower SR thresholds, a shortened latent period and a stronger reaction as compared with the healthy subjects which was suggestive of the irritation of the mesencephalic activating mechanisms in patients during the period of abstinence. Intake of the euphorizing doses of ethanol depressed the acoustic SR in both patients and controls. It is concluded that ethanol exerts an inhibitory action on the midbrain system of brain nonspecific activation.