Intraventricular infusion of nerve growth factor as the cause of sympathetic fiber sprouting in sensory ganglia.
OBJECTIVE
The results of previous clinical trials have indicated that intraventricular infusion of nerve growth factor (NGF) in patients with Alzheimer's disease is frustrated by the appearance of weight loss and diffuse back pain. The present study tested whether NGF induces sympathetic sprouting in sensory ganglia. Such sprouting has been implicated in previous studies as a possible mechanism of sympathetically maintained pain in neuropathic animals.


METHODS
Nineteen Long-Evans rats underwent intraventricular infusion of either artificial cerebrospinal fluid (ACSF; seven animals) or NGF (12 animals). After 14 days of infusion, the sensory ganglia of the trigeminal nerve and the C-2, C-8, T-1, L-4, and L-5 dorsal roots were examined for sympathetic sprouting by using tyrosine hydroxylase immunohistochemical analysis.


CONCLUSIONS
In the animals receiving NGF, 52 of 144 ganglia showed sympathetic fiber sprouting. In the control animals receiving ACSF, only two of 72 ganglia showed minor sympathetic fiber sprouting. A preferential sprouting of sympathetic fibers was demonstrated at lower lumbar ganglia compared with the cervical and thoracic ganglia. The data presented here demonstrate that in the rat intraventricular NGF infusion caused sympathetic sprouting in dorsal root ganglia (p < 0.01). These findings may have importance both for the treatment of Alzheimer's disease and the understanding of neuropathic pain.
Nauta
H J
HJ
Department of Anatomy and Neurosciences, and Marine Biomedical Institute, University of Texas Medical Branch, Galveston 77555-1069, USA.
Wehman
J C
JC
Koliatsos
V E
VE
Terrell
M A
MA
Chung
K
K
D000544:Alzheimer Disease / Q000188:drug therapy; D000818:Animals; D002552:Cerebral Ventricles; D002555:Cerebrospinal Fluid; D004195:Disease Models, Animal; D017950:Ganglia, Sensory / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D005727:Ganglia, Spinal / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development; D005728:Ganglia, Sympathetic / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D007150:Immunohistochemistry; D007267:Injections; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D009414:Nerve Growth Factors / Q000008:administration & dosage / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology; D051381:Rats; D014276:Trigeminal Nerve / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D009414:Nerve Growth Factors; D014446:Tyrosine 3-Monooxygenase