The maturation of 5-hydroxytryptophan decar☐ylase in regions of the mouse brain

Abstract

5-Hydroxytryptophan decar☐ylase (5-HTPD) activity has been measured in 4 subdivisions of the mouse brain during various stages of postnatal maturation. Each region demonstrated a different pattern of maturation. During the first few days post-partum increases in enzyme activity are slower than increases in tissue weight for all regions studied. However, by the end of the first week all regions are undergoing rapid increases in enzyme activity. Maturation of the enzyme proceeds in a caudal rostral direction, with cerebellum and medulla-pons reaching adult-like status by 2 weeks, mesencephalon-diencephalon by 4 weeks and cerebral hemispheres sometime after 6 weeks. Comparisons of these enzyme data to previously reported data for 5-hydroxytryptamine (5-HT) maturation, measured upon a similar basis, indicate that the enzyme (5-HTPD) and its product (5-HT) mature differently in all regions.