Investigation of the functional role of the septum.

A spectral-correlation analysis was made of the EEG recorded from the motor and visual cortex, hippocampus, and septum (in some series of experiments, the lateral geniculate body and mesencephalic reticular formation also) of rabbits in the presence or absence (background) of sensory stimulation. To investigate the functional role of the septum as a pacemaker the method of "rhythm binding" by electrical stimulation of the septum (lateral and medial nuclei) was used. By electrical stimulation of the medial nucleus of the septum at a frequency of 4-30 Hz rhythm binding was successfully obtained in all regions studied. Maximal rhythm binding was observed in cortical potentials. It is postulated that cortical rhythmic activity is generated as a result of physiological interaction between cortex and septum.