Fig. 4.

GnIH cells target a large proportion of GnRH somata. The GnRH system is distributed from the septum to the caudal aspect of the hypothalamus, and GnRH cells in all brain regions are similarly contacted (Inset depicts the distribution of GnRH-immunoreactive cells numbers across brain regions) (A). GnRH cells were investigated by using wide-field (B) and confocal (C) microscopy. Both B and C depict fibers for GnIH “tracking” the GnRH fiber and cell body; presumptive boutons are evident. GnIH administration either i.c.v. (D) or i.p. (E) leads to marked and rapid reductions in LH.