title: Developmental profile of NGF immunoreactivity in the rat brain: a possible role of NGF in the establishment of cholinergic terminal fields in the hippocampus and cortex.
abstract: In the current investigation, we have examined the developmental profile of nerve growth factor immunoreactivity (NGF-ir) in the postnatal rat. During the first 3 weeks after birth, NGF-ir was observed within the hippocampal mossy fiber region, where it persists throughout adulthood and appeared transiently within three additional zones-the dentate gyrus supragranular zone, the tenia tecta/intermediate lateral septum, and the cingulate/retrosplenial cortex. In all cases, the appearance of NGF-ir progressed in a rostrocaudal pattern over time. A strong correlation was seen between the pattern of NGF-ir and cholinergic innervation in the dentate gyrus supragranular zone, both spatially and temporally, suggesting that NGF may direct the innervation of cholinergic afferents to this region. A spatial correlation was also observed between NGF-ir and cholinergic innervation within the retrosplenial cortex and tenia tecta. With our current techniques, however, we were unable to determine at what point during development the adult-like pattern of cholinergic terminal innervation in these regions occurred and, thus, were not able establish a temporal correlation in these regions. Within the cingulate cortex, there was no evidence suggesting that the developmental appearance of NGF-ir in this region was associated with a specific enhancement of cholinergic innervation. Thus, the results of the current investigation clearly identify the presence of transiently occurring zones of NGF-ir during postnatal CNS development, although defining their exact functional role will require additional investigation.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla 92093, USA. jmconner@ucsd.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Conner
authors.forename: S
authors.initials: S
authors.lastname: Varon
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D001921:Brain / Q000254:growth & development*; D001923:Brain Chemistry / Q000502:physiology*; D002540:Cerebral Cortex / Q000254:growth & development* / Q000502:physiology*; D006624:Hippocampus / Q000254:growth & development* / Q000502:physiology*; D007150:Immunohistochemistry; D009411:Nerve Endings / Q000502:physiology; D009414:Nerve Growth Factors / Q000378:metabolism* / Q000502:physiology*; D010275:Parasympathetic Nervous System / Q000254:growth & development* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism
chemical_list: D009414:Nerve Growth Factors; D017475:Receptors, Nerve Growth Factor