Further evidence for a correlation between EEG synchronization and plasma DBH activity in normal subjects

In a former investigation we had got evidence for a relationship between synchronization of the resting EEG and plasma dopamine-beta-hydroxylase (DBH) activity in healthy males. In order to substantiate this finding we now examined a new sample of males and a sample of females, both with either low-voltage or monotonous alpha-EEGs, and relatives of probands with either EEG type. In the new sample of males, the carriers of a low-voltage EEG (n = 15) again had significantly lower plasma DBH activity than the subjects with a monotonous alpha-EEG (n = 16). In females there was no difference. In the families of probands with a monotonous alpha-EEG the relatives carrying the trait significantly exceeded non-trait-carriers in DBH activity. This effect is mainly due to the male subjects, confirming the results in the proband groups. Presumably there are common genetic factors that contribute to the variability of both the EEG and DBH.--Taking into account experimental findings on central catecholaminergic activity and EEG synchronization, a hypothesis on the mechanisms that are responsible for the relationship is proposed.