ONTOGENY OF GABA PATHWAY IN HUMAN FETAL BRAINS

The developmental profiles of gamma-aminobutyric acid (GABA), its bios ynthesizing enzyme L-glutamic acid decarboxylase (GAD) and its degrada ting enzymes gamma-aminobutyric acid-alpha-ketoglutaric acid transamin ase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH) in four d ifferent regions of human fetal brains have been evaluated. The GABA p athway was found to be maximally active in fetal brains during the thi rd trimester of pregnancy. The relative activities of the enzymes as w ell as GABA content were least in pens compared to cerebrum, cerebellu m and mid brain regions throughout the period of fetal development. (C ) 1996 Academic Press, Inc.