EN
The medial septal nucleus (MS) is a forebrain limbic structure involved in learning and memory mechanisms. In previous study we found that electrolytic lesion of the medial septal nucleus caused depression of the peripheral blood natural killer cell cytotoxicity (NKCC) and the leukocyte number. In the sham operated group mere insertion of electrodes into the MS evoked transient NKCC enhancement, probably resulting from mechanical MS stimulation. To check this effect in the present study, we evaluated both spleen and blood NKCC (51Cr-release assay) and large granular lymphocytes (LGL) number (a morphological method) after chronic electrical stimulation (constant current 0.1 ms duration cathodal pulses delivered at a frequency of 50 Hz during 30-min daily session for 14 consecutive days) of MS in conscious, freely moving rats (n=12). Additionally, peripheral blood leukocyte, lymphocyte and neutrophile number was mesaured. Chronic MS stimulation caused signifi cant blood NKCC augmentation and LGL number (25.86 ± 9.31% vs. 15.75 ± 4.75%, P<0.01) in comparison to the sham group (n=13). No signifi cant effect was found in the spleen (27.14 ± 9.99% vs. 28.58 ± 8.04%). A week after termination of the stimulation procedure all measured parameters returned to the baseline. The results obtained indicate that such limbic structure as medial septum enhances antitumor and antiviral function and number of NK cells.