Experimental and immunohistochemical studies on the cerebellar substance P of the rat: localization, postnatal ontogeny and ways of entry to the cerebellum.
With the indirect immunofluorescence technique, the localization (including the postnatal ontogeny) of substance P in the cerebellum, and the ways of entry of substance P-containing fibers into the cerebellum were explored. In the newborn rat cerebellum, dense fiber bands of axons with substance P-like immunoreactivity which can be traced to the lower brain stem are found. These fibers are also traceable to the developing granular cell layer. Two weeks after birth, however, substance P-containing structures seen in the cerebellum begin to decrease progressively and in the cerebellum of the adult rats, only a small amount of substance P-containing structures is observed. The present study established that substance P-containing fibers are mostly derived from extracerebellar substance P-containing cells and demonstrated the presence of three sites of entry of these substance P-containing fibers to the cerebellum, via (1) the inferior cerebellar peduncle, (2) the fasciculus uncinatus and (3) the middle cerebellar peduncle, respectively. Following deafferentation of the cerebellum, substance P-accumulating fibers are observed only ventral to the lesion (i.e. on the brain stem side), while in the cerebellum a remarkable decrease of substance P-containing fibers is seen and no substance P-accumulating fibers are found dorsal to the lesion (cerebellar side).
D000344:Afferent Pathways / Q000378:metabolism; D000375:Aging; D000818:Animals; D002529:Cerebellar Nuclei / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D051381:Rats; D013373:Substance P / Q000378:metabolism*
D013373:Substance P