Muscle reinnervation with delayed or immediate transplant of embryonic ventral spinal cord cells into adult XXXX peripheral nerve.

@entity4094 @entity2137 @entity575 @entity5251 @entity35 @entity2057 @entity528 @entity130
Muscle denervation is common in various @entity4094 and after @entity130 . It induces skeletal @entity2057 . Only muscle reinnervation leads to functional recovery. In previous studies, denervated adult @entity35 muscles were rescued by transplantation of embryonic day 14-15 (E14-15) ventral spinal cord cells into a nearby peripheral nerve. In the present study, changes were made in the environment into which the cells were placed to test whether reinnervation was improved by: 1) prior @entity528 , induced by sciatic nerve transection 1 week before cell transplantation; 2) transplantation of 1 million versus 5 million cells; 3) addition of @entity2137 ( @entity2137 ) to the transplant. Ten weeks after cell transplantation, axons had grown from all of the transplants. The numbers of myelinated axons that regenerated into the tibial, medial (MG), and @entity5251 ( @entity5251 ) nerves were similar across treatments. The mean diameters of large @entity5251 axons (>6 microm) were significantly larger with @entity528 before transplantation. The mean diameters of MG and @entity5251 axons were significantly larger with transplantation of 1 million versus 5 million cells. @entity575 -stained experimental and control lateral gastronemius (LG) muscles showed axons that terminated at motor end plates. Nodal and terminal sprouts were more common in reinnervated muscles (45-63% of all end plates) than in control muscles (10%). Electrical stimulation of the transplants induced weak contractions in 39 of 47 MG muscles (83%) and 33 of 46 LG muscles (72%) but at higher voltages than needed to excite control muscles. The threshold for MG contraction was lower with transplantation of 1 million cells, while LG thresholds were lower without @entity2137 . The cross-sectional area of whole LG muscles was significantly larger with cell transplantation (immediate or delayed) than with media alone, but all of these muscle areas were reduced significantly compared with control muscle areas. These data suggest that delayed transplantation of fewer cells without @entity2137 assists regeneration of larger diameter axons and prevents some @entity2057 .
