[Relationship between the frequency of self stimulation and the strength and duration of stimulation]

In experiments on thirteen rats with electrodes in the lateral hypothalamus, with a simultaneous change in current intensity I and of stimulation duration T, two variants were obtained of the empirical response surface of the self-stimulation (SS) frequency: with the maximum SS frequency, located within the surface boundaries (peak variant), and with the maximum at one of its boundaries (side variant). An equation has also been deduced on the regression of SS frequency on the parameters I and T, which quite accurately defines the experimental and rated data (R = 0.57 divided by 0.97). It has been established that current intensity has a greater effect on SS frequency as compared with the stimulation duration and that the influences of these parameters are relatively independent of one another.