A combination of BDNF and NT-3 promotes supraspinal axonal regeneration into Schwann cell grafts in adult rat thoracic spinal cord.
Exp Neurol
; 134(2): 261-72, 1995 Aug.
Article
en En
| MEDLINE
| ID: mdl-7556546
ABSTRACT
We previously demonstrated that Schwann cells (SCs) in semipermeable guidance channels promote axonal regeneration in adult rat spinal cord transected at the mid-thoracic level. Propriospinal but not supraspinal axons grew into these channels. Here, we tested the ability of exogenous brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) to promote axonal regeneration in this novel model. The two neurotrophins were delivered simultaneously into the channel by an Alzet minipump at a rate of 12 micrograms/day for each neurotrophin for 14 of 30 days tested; phosphate-buffered saline, the vehicle solution, was used as a control. Significantly more myelinated nerve fibers were present in SC/neurotrophin grafts than in SC/vehicle grafts (1523 +/- 292 vs 882 +/- 287). In the graft, at least 5 mm from the rostral cord-graft interface, some nerve fibers were immunoreactive for serotonin, a neurotransmitter specific to raphe-derived axons in rat spinal cord. Fast blue retrograde tracing from SC/neurotrophin grafts revealed labeled neurons in 10 nuclei of the brain stem, 67% of these being in the lateral and spinal vestibular nuclei. The mean number of labeled brain stem neurons in the SC/neurotrophin group (92; n = 3) contrasted with the mean in the SC/vehicle group (6; n = 4). Our results clearly demonstrate that BDNF and NT-3 infusion enhanced propriospinal axonal regeneration and, more significantly, promoted axonal regeneration of specific distant populations of brain stem neurons into grafts at the mid-thoracic level in adult rat spinal cord.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Células de Schwann
/
Médula Espinal
/
Axones
/
Factores de Crecimiento Nervioso
/
Regeneración Nerviosa
/
Proteínas del Tejido Nervioso
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Exp Neurol
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos