Changes of acid and alkaline phosphatase activities in the developing mouse brain.

Acid and alkaline phosphatase activities in the mouse cerebrum, brainstem and cerebellum increased during the late fetal and perinatal period and reached a maximum on postnatal day 28 (P28). Myelination was most extensive on P28-P45 in the brainstem and in the cerebellum, and phosphatidic acid phosphatase activity concomitantly decreased to a low level after birth. The changes in acid and alkaline phosphatase activities correlate more with the extent of myelination than with the overall brain tissue growth.