A possible role for BDNF, NT-4 and TrkB in the spinal cord and muscle of rat subjected to mechanical overload, bupivacaine injection and axotomy

Effects of exercise and muscle type on BDNF, NT‐4/5, and TrKB expression in skeletal muscle

“…In this study we have demonstrated that BDNF expression is higher in soleus, a muscle comprised primarily of slow-twitch fibers, 31 as compared with the mixed but predominantly fast-twitch medial gastrocnemius. 32 Whereas one study found no trace of BDNF protein in skeletal muscle, 18 we readily detected mRNA species for BDNF in soleus and medial gastrocnemius, consistent with findings of other investigations. 1,9-11 Using immunohistochemistry, Mousavi and Jasmin 3 indicated that BDNF protein is not present in the mature myofiber but rather localized to adjacent satellite cells, indicating that fiber-type-specific expression does not occur.…”

“…1,17 Expression of NT-4/5 mRNA increases during early postnatal development in both soleus and medial gastrocnemius, coinciding with periods of increasing neuromuscular activity. 1,18 When NT-4/5 mRNA expression is induced through electrical stimulation of the sciatic nerve, the increased expression is proportional to the duration and intensity of stimulation. 1 A similar relationship between NT-4/5 protein and electrical stimulation has not been demonstrated.…”

“…We sought to determine if the previously demonstrated elevation of BDNF mRNA produced with 5 days of exercise 10,11 is sustained over a 10-day exercise program. As equivocal data exist regarding fiber-type-specific expression of musclederived neurotrophins 1,[16][17][18] we evaluated neurotrophin expression in the predominantly slowtwitch soleus and fast-twitch medial gastrocnemius. By evaluating the effects of brief bouts of treadmill exercise on BDNF and NT-4/5, we aimed to determine whether exercise would be an appropriate model to demonstrate the significance of musclederived neurotrophins in the adaptation of the neuromuscular system to increased activity.…”

Effects of acute selective pudendal nerve electrical stimulation after simulated childbirth injury

“…However, vaginal distension causes a significant decrease of BDNF and other neurotrophins in the EUS (40) since the distension liking childbirth during delivery damages the EUS and its neuromuscular junctions, such as striated muscle fiber disruption and atrophy and acetylcholine receptors and neurofilament in a precisely overlapping distribution with no associated proximal axon (30,40). Generally, BDNF downregulation after muscle injury enables neuromuscular junction repair (46), but in childbirth injury is associated with delayed pudendal nerve regeneration after VD and PNC, both functionally and anatomically (27,40). Exogenous BDNF has been shown to improve urinary continence and EUS recovery after simulated birth injury (17).…”

“…After muscle injury, expression of neurotrophins decreases, and BDNF becomes undetectable (46). Decreased neurotrophin expression in the EUS and delayed functional recovery of the urethra and pudendal nerve have been demonstrated in a simulated childbirth injury model, consisting of both vaginal distension (VD) and pudendal nerve crush (PNC) (9,27,40).…”