Transient expression of synaptogyrin in the ganglionic eminence of the human fetal brain.

The ganglionic eminence (GE) representing a conspicuous bulb-like elevation of the telencephalic proliferative zone has recently been shown to be involved in the establishment of cortical connections. This study demonstrates the presence of synaptogyrin-immunoreactivity in a large number of cell bodies of the human GE between 12 and 20 weeks of gestation. From the 20th week onwards synaptogyrin expression sharply declines. No immunoreactive structures are detectable in the 23rd week or later. As the GE persists nearly throughout the entire fetal period these results show that its neurochemical features change distinctly in the course of development. The synaptogyrin-immunoreactive GE-cells may form an early corticopedal connection which provides a scaffold for outgrowing cortical axons.