Acute electrical stimulation of lateral hypothalamus increases natural killer cell activity in rats

Natural killer cell (NK) activity in WKA and SD rats was found to be significantly higher following electrical stimulation of the lateral hypothalamus (LH) compared to sham operated. There was no such difference between sham operated rats and those receiving electrical stimulation in the frontal cortex as a control. Operations were performed under sodium pentobarbital anesthetic, and NK activity against YAC-1 target cells was measured 20 h later using 51Cr release assay. The LH area stimulated is a potent reward center and that stimulation of this point increased NK activity opens the possibility that pleasure might play a role in cellular immunity.