title: Effects of nerve growth factor and its antibodies on sprouting of sensory axons following spinal cord hemisection.
abstract: Axons were counted in rat dorsal roots three segments cranial and three segments caudal to a spinal hemisection done at birth. The animals were placed in three groups: (1) hemisected (HEMI), (2) hemisected and given nerve growth factor (NGF) daily (HEMI + NGF) and (3) hemisected and given antibodies to NGF daily (HEMI + anti-NGF). They were sacrificed at 1 month. In the HEMI and HEMI + NGF groups, there were 20% and 13% more unmyelinated axons, respectively, in roots of the operated side. We interpret these differences to be the result of sprouting of unmyelinated axons as a result of denervation, and exogenous NGF does not seem to affect the response. By contrast, the unmyelinated axon responses in HEMI + anti-NGF animals are different. These animals have approximately 7% more unmyelinated axons on the denervated side and 50% more axons on the normal side than in the other animals we studied. The results on the anti-NGF animals are interpreted as indicating sprouting in response to a chemical denervation caused by NGF removal and the response is more dramatic on the unoperated side.
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D009414:Nerve Growth Factors / Q000502:physiology / Q000627:therapeutic use*; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000503:physiopathology; D014945:Wound Healing / Q000187:drug effects
chemical_list: D009414:Nerve Growth Factors