Effect of short-term ethanol exposure on the suprachiasmatic nucleus of hypothalamus: immunohystochemical study in mice.

Morphological changes of the suprachiasmatic nucleus (SCN) of the hypothalamus were investigated in mice exhibiting intoxication signs of stages 2 or 3 after a short application term of 6% ethanol. Alterations in glial cells and neurons were examined using anti-glial fibrillary acidic protein (GFAP) and anti-calbindin D28k monoclonal antibody, respectively. The results revealed that short-term ethanol exposure led to strong expression of GFAP-immunoreactivity (GFAP-IR) in the dorsomedial part of the SCN. Furthermore, GFAP-IR astrocytes showed an increase in number and hypertrophy with longer processes. However, calbindin D28k-IR neurons were apparently little changed in the SCN. It is concluded that neuroadaptive response of astrocytes could occur before the neurotoxic effects emerge on neurons on the SCN.