Fos and GFAP expression in different parts of hypothalamus in simulated weightlessness in rats

AIM To research the functions of rat hypothalamus under long term simulated weightlessness condition. METHODS By using anti Fos and anti GFAP immunohistochemical ABC methods, we observed changes of hypothalamus neurons and astrocytes in 4 wk simulated rats. RESULTS Expressions of Fos and GFAP positive cells were only found in paravetricular nuclei of the hypothalamus, especially in mango cellular part, supraoptic nuclei and suprachiasmatic nuclei, with negative reaction in other areas. The reactive astrocytes were featured with hypertrophy of the cell body and cytoplasmic processes. CONCLUSION These nuclei in hypothalamus may participate in the reaction to long term weightlessness, and probably be associated with increased secretion of vasopressure.