Development of the human corpus striatum and the presence of nNOS and 5-HT2A receptors.

This study focussed on the development of the corpus striatum in the fetus, using silver impregnation and immunohistochemistry. For the latter, we looked for nNOS positive cells and 5-HT(2A) receptors positive cells in the corpus striatum during development. During the initial formation of the corpus striatum, there was migration cells of the ganglionic eminence toward the putamen by 15-17 weeks of gestation. Process formation in the neurons started by week 17 and became very complex before term (31/32 weeks of gestation). By 25-27 gestational weeks, the globus pallidus already had two parts and the corpus striatum was similar to the adult in configuration. The nNOS positive cells appeared early (21-23 weeks in gestation) while 5-HT(2A) receptors positive cells were not observed until 31/32 weeks gestation. The number of positive cells in both groups was relatively small. It is anticipated that further developmental changes would occur in the postnatal/neonatal phases.