title: Prenatal and postnatal development of substance P immunocytochemistry within subnuclei of the rat interpeduncular nucleus.
abstract: In the present study, the temporal appearance and distribution of substance P within individual subnuclei has been examined during the development of the rat interpeduncular nucleus (IPN). The prenatal organization as well as migration pattern of individual IPN subnuclei are also described. The IPN was distinguishable on embryonic day (E) 19, near the ventral mesencephalon. At this age, the IPN was organized into individual subnuclei like the adult, except for a bilateral distribution of presumptive rostral neurons. Rostral neurons were merged into a single, midline subnucleus by the day of birth, thereby completing an adult pattern of subnuclear organization. SP immunoreactivity, restricted to the lateral subnuclei, was first detected at E20. The intensity of SP-positive fibers in the lateral subnucleus increased with age, and appeared to become selectively distributed along both the medial and lateral borders of this subnucleus. Additional SP-positive fibers became evident postnatally in a thin band overlying both central and intermediate subnuclei, and within the dorsal medial, central and apical subnuclei. SP-positive cell bodies were present in the rostral subnucleus on postnatal day 28, thereby completing the development of an adult pattern of SP immunoreactivity within the IPN.
mesh_terms: D000818:Animals; D005314:Embryonic and Fetal Development; D005260:Female; D007150:Immunohistochemistry; D008636:Mesencephalon / Q000166:cytology / Q000196:embryology / Q000254:growth & development*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000032:analysis* / Q000276:immunology
chemical_list: D013373:Substance P