γ− Aminobutyric Acid Content and Glutamic Decarboxylase Activity in Developing Mouse Brain

Summary

Brain weights, content of ^γ−aminobutyric acid, and the activity of glutamic acid decarboxylase were determined in brains of mice at various stages of postpartum development. All of the quantities studied increased greatly during postnatal development, attaining their maximal levels at 90 days. The increase in decarboxylase activity was slower during the first two weeks than that of the weight and the ^γ−aminobutyric acid. A cytological study revealed that the period of greatest increase in glutamic acid decarboxylase activity is correlated with the period of greatest increment in features which are related to maturation of the central nervous system. Examination of selected samples of nervous tissues of the cat, dog, and rabbit showed that the glutamic decarboxylase-^γ−aminobutyric acid system is present chiefly in the gray matter of the central nervous system. The results of the present study were correlated with relevant data from the literature.