Stimulus factors in septal self-stimulation

¹ Department of Physiology, Stanford University, Stanford, California

The parameters of electrical stimuli effective in producing sustained self-stimulation behavior were studied in the septal region in rats. Constant current sine wave stimuli were effective over a wide, but specific, range of frequencies, 40–1000 cps, suggesting that the proper choice of stimuli might separate effects essential to the self-stimulation phenomenon from any concomitant but unrelated effects having different frequency sensitive characteristics. The interrelation of current, pulse duration, and frequency using a modified rectangular wave form at low frequencies was explored by threshold measurements. The quantity of electricity delivered for each bar press was more important than either the frequency or pulse current per se, but this in turn depended on the pulse duration used. The longer the pulse duration the more coulombs were required to achieve threshold. Single pulses were ineffective in producing sustained self-stimulation.