Slowing of heart rate after septal self-stimulation in rats

Heart rate, recorded continuously from rats trained to press a bar for intracranial electrical stimulation of their septal areas, fell consistently after brain stimulation. Interpretation of the rewarding effect of septal stimulation had previously been limited by the absence of any data on the autonomic effects of the stimulation. The results of this study suggest that the rewarding effect may possibly be produced by a parasympathetic (quieting) reaction of the autonomic nervous system to septal stimulation.