Parallel development of blood vessels and mast cells in the lateral geniculate nuclei.

The present study examined quantitatively developmental changes of the vasculature in the dorsal (dLGN) and the ventral (vLGN) lateral geniculate nuclei together with concomitant changes in the number of mast cells (MCs), known for their role in angiogenesis. Vascular network, marked after transcardial perfusion of India ink, and MCs detected with conventional histochemical techniques were examined at postnatal days (P) 1, 8, 14, 21, 31, 90 and 300 of Wistar rats. Quantitative analysis by means of an image analysis system showed age-dependent changes in both vascular parameters [vascular area and relative frequency (%) of capillaries and medium- and large-diameter vessels] and mast cells number in the developing dLGN and vLGN. Despite quantitative differences in the vascularization and MC infiltration between the two nuclei at some age points, MC number, vascular area and the percentage frequency of capillaries exhibited similar developmental time courses, especially up to the end of the first postnatal month. Both MC number and the capillary frequency reached maximal levels at P31 and declined thereafter, following a massive or a partial, respectively, decrease up to P300.