Effect of glucoprivation on self-stimulation rate-frequency functions.

In a series of two experiments using rats, the effect of glucoprivation, induced by 2-deoxy-D-glucose (2-DG) or insulin injections, on self-stimulation rate-frequency functions, was evaluated at two levels of current intensity. At the higher current intensity, neither insulin nor 2-DG produced a significant change in rate-frequency function parameters. At the lower current intensity, insulin suppressed asymptotic responding while 2-DG produced a lateral curve shift. Results of this study would argue that glucoprivation produces changes in self-stimulation at lateral hypothalamic electrodes that are: a) unrelated to the involvement of the neurons in stimulation-induced eating, b) are most notable when a smaller number of reward relevant neurons is stimulated, and c) can be differentially attributed to changes in motoric performance capacity during insulin tests and to changes in the reward value of stimulating current during 2-DG tests.