Morphometric analysis of hypothalamic cells showing c-Fos proteins after movement restriction and EHF-irradiation

A morphometric analysis of hypothalamic cells containing c-Fos-like protein detected by an indirect immunoperoxidase method was carried out to clarify the responses to movement restriction and skin electromagnetic high frequency (EHF) irradiation (7.1 mm, 42.2 GHz, 20 mW output power) simultaneously to three acupuncture projection areas. The morphometry of c-Fos-protein positive neurons by their number and type was analyzed. Movement restriction (40 min) induced c-Fos protein expression primarily in cells with 10-50 μm2 sizes (associative type neurons) only in anterior hypothalamic nucleus and lateral hypothalamic area; while additional EHF-irradiation of acupuncture projection areas (under movement restriction) induced c-Fos expression in all hypothalamic structures and mostly in cells with 70-150 μm2 sizes (relay type neurons), i.e. changed the pattern of activated cell type distribution. In conclusion, the findings show that modest stress under which experimental animals often are exposed increase c-Fos protein expression in hypothalamic centers and skin EHF-irradiation of acupuncture projection areas seem to increase that.