Modulation of non-specific immunity by hippocampal stimulation.

Rats subjected to electrical stimulation of hippocampus (30 min/day for 4 days) showed an increase in the neutrophils in the peripheral blood when compared to sham (P < 0.01) and controls (P < 0.001). They also showed a significant decrease in lymphocytes, when compared to control rats (P < 0.001). Both sham and stimulated animals showed a significant decrease in total white blood cell count when compared to controls (P < 0.001). The phagocytic index of stimulated animals showed a significant increase from control (P < 0.001) and sham (P < 0.001). In addition, the stimulated animals showed a significant (P < 0.001) decrease in plasma corticosterone level when compared to sham and controls.