Interleukin-6 receptor is highly expressed in the ganglionic eminence of the human fetal brain

The expression of interleukin-6 receptor (IL-6R) has been investigated immunohistochemically in seven fetal brains with special reference to the ganglionic eminence (GE), a part of the telencephalic proliferative zone. Between the 22nd and 28th gestational week the GE stands out conspicuously due to its very high amount of intensely IL-6R-immunostained cells. Adjacent brain areas exhibit only very weak immunoreactivity. Between the 32nd and 36th week a moderate IL-6R immunolabelling is seen in the remnants of the GE. IL-6 may activate the immature IL-6R-positive cells to secrete a protease which is likely to be involved in GE involution and, perhaps, in the development of hemorrhage frequently occurring in the GE of premature infants.