Effects of control and 0.25, 0.50, and 1 tablet of Neurexan on the spectral frequencies in four rat brain areas (frontal cortex [A], hippocampus [B], striatum [C], and reticular formation [D]). The encephalographic (EEG) signatures were obtained between 185 and 245 minutes after oral administration of a single dose of Neurexan. Changes of δ-, θ-, α1-, α2-, β1-, and β2-waves are presented as percentage of predrug baseline. The data of eight rats are summarized as mean ± SEM. Significant differences to vehicle controls (0.9% NaCl) are indicated by asterisks (P < 0.01).