The state of degeneration and the resulting reactions were studied in grown cats subjected to damage of the Fallopian canal.
1) By sharply amputating the nerves and obstructing their regeneration, I studied the rate of nerve degeneration and the process of cell number decrease for a period of time, in an attempt to discover a particular pattern.
The degeneration rate was found to increase after the amputation and reached a peak of 33% at 2 weeks. The rate then decreased to 0% in 4 weeks. The number of cells also decreased gradually during the period.
2) Another observation was made by binding and applying pressure to the nerve trunk of 1/2, 1/3 and 2/3 size of the diameter.
As a result, the degeneration of motor nuclear cells reached a peak of 37% in 2 weeks regardless of the severity of pressure. In 10 weeks, the degeneration decreased to near 0%. The rate of decrease in number of cells, however, varied according to the severity of the pressure.
3) In another case, the binding was removed during the course of study and the rate of degeneration and the cell-number decrease was observed in those cases.
The effect of relieved pressure on degeneration reached a peak on or before the 12th day after the operation. This finding parallels observations made in experiments on the decompression of peripheral nerves by Yamamoto & Fisch. (Proceedings, Third Int. Symposium on Facial Nerve Surgery, 1976.)
From the above findings, the dynamics of degeneration of cells were clarified and clinical problems such as partial treatment of Bell's palsy and synkinesis were further explored.