Alkaline phosphatase activity in the ganglion cells in and near the temporal bone

The distribution pattern of alkaline phosphatase was studied in the ganglion cells in and near the temporal bone of some mammals. No or extremely weak activity of alkaline phosphatase was observed in or near the spiral and vestibular ganglion cells of the bat, rat, cat, and monkey. However, intense to moderate enzyme activity was noted exclusively in the peripheral areas of the spiral and vestibular ganglion cells of the guinea pig. The enzyme activity was also demonstrated in the nerve fibers at some distance from both axonal and dendritic processes of the spiral and vestibular ganglion cells of the guinea pig. Trigeminal and geniculate ganglion cells of all mammals examined showed intense to moderate enzyme activity in their capsular cells. There is a marked difference in the phosphate metabolism in the capsular tissues of the ganglion cells in or near the temporal bone of various mammals.