Two self-shaping methods for intracranial self-stimulation in rats

Shaping an animal for intracranial self-stimulation (ICSS) by manual reinforcement of successive approximations to the desired response can be tedious and time-consuming and may produce inappropriate behaviors. To test alternative shaping methods, rats were implanted with bipolar electrodes aimed at the medial forebrain bundle; one group was shaped manually, another group was allowed to acquire the bar-press response for food reward before implantation and then ICSS was substituted for food, and a third group was allowed to shape themselves spontaneously for ICSS through exploratory behavior. It was concluded that spontaneous shaping produces stable responders with less investment of time and expertise than do the other two methods.