Abstract
Alanine aminotransferase has been studied in various nervous tissues during the postnatal development of the rat. At birth the enzyme activity was low and showed similar levels in all tissues studied. In the hippocampal formation and in the cerebellum which are supposed to be endowed with glutamatergic structures, the enzyme activity increased significantly during the postnatal development. These results contrast markedly with dorsal root ganglia and superior cervical ganglia, in which glutamatergic transmission processes are obviously absent. In these peripheral ganglia the time course of the enzyme activity persisted on a very low level after birth. The participation of alanine aminotransferase in forming of transmitter glutamate is discussed.