Hippocampal and cerebral cortical sequencing of cardiac activity--theta rhythm (4-10Hz).

Interaction of repetitive evoked potentials using visual and auditory stimuli has been show for the hippocampus and cerebral cortex. Selected components of the electrocardiogram (EKG) are used to stimulate certain nuclei of the amygdala. Extracellular unit potentials of the hippocampus shown repetitive activity. The micro-EEG of the cerebral cortex and dorsal hippocampus show rhythmic activity. In the hippocampus computer analysis of these analog signals show an increase of the theta rhythm related to the EKG (QRST) stimulation. Repetitive activity related to the heart rate (EKG) is evident in the cerebral cortex during stimulation.