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Ontogeny of the peptidergic system in the rat spinal cord: Immunohistochemical analysis
Author(s) -
Senba Emiko,
Shiosaka Sadao,
Hara Yoshinobu,
Inagaki Shinobu,
Sakanka Masahiro,
Takatsuki Kenichi,
Kawai Yuriko,
Tohyama Masaya
Publication year - 1982
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.902080105
Subject(s) - spinal cord , biology , somatostatin , ontogeny , neurotensin , medicine , neuropeptide , endocrinology , central nervous system , fetus , substance p , period (music) , anatomy , neuroscience , receptor , pregnancy , genetics , physics , acoustics , biochemistry
The ontogeny of neuropeptides, such as somatostatin (SRIF), substance P (SP), leucine‐enkephalin (LE), and neurotensin (NT) in the spinal cord (including the spinal ganglion) of the rat, was examined by means of the indirect immunofluorescence method. SRIF and SP appear in the early fetal period before the establishment of the spinal synaptic transmission system, and their appearance precedes that of LE and NT, thus suggesting that SRIF and SP might have some important role in the development of the spinal cord. Furthermore, a number of SRIF‐positive structures are found during the fetal period in the spinal cord; however, SRIF‐positive fibers in the ventral horn, lamina V, VI, and X tend to decrease remarkably in number after birth, while those found in the dorsal horn maintain their immunoreactivity even in the adult rats. These facts suggest that SRIF in the latter area might function as a neurotransmitter, whereas in the former areas, SRIF might have another role in the development of the spinal cord. SP‐positive structures also made their appearance during the fetal period. SP‐positive fibers continue to increase in number after birth, and they can be seen throughout the entire spinal cord even in the adult rats. It becomes difficult to identify SP‐positive neurons as the rats grow. Numerous SP‐positive cells are demonstrated, however, by colchicine pretreatment, thus suggesting that this system is functioning actively in the adult rats. LE‐and NT‐positive structures appear at perinatal stages and they continue to increase in number after birth. These facts suggest that these peptides (SP, LE and NT) might act as neurotransmitters.