[Pathohistological changes in superior cervical ganglion after exposure to 99.5% ethyl alcohol]

The author attempted to clarify the histological changes after exposure to ethyl alcohol of superior cervical ganglion (SCG) cells in chronological order. Adult rat SCGs in situ were immersed in ethyl alcohol for various durations and were observed under light microscopy after fixation and histological processes. In almost all cases, the visages of the cells were in devastated state, although the grade of inflammatory reaction depends on the duration of exposure to the ethyl alcohol. In cases of short-lasting immersion, only the cells located near the capsule showed the so-called coagulation necrosis and those at the center of SCG were not so severely affected. Inflammatory reactions characterized by cellular invasion was also determined by duration of ethyl alcohol exposure. Number of normal neurons decreased until 60 days after immersion. From this study, it was revealed that complete ethyl alcohol blocking of the SCG depends on the duration of immersion time and the days after this procedure.