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.
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.
Conner
J M
JM
Department of Biology, University of California, San Diego, La Jolla 92093, USA. jmconner@ucsd.edu
Varon
S
S
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
D009414:Nerve Growth Factors; D017475:Receptors, Nerve Growth Factor