Neurotrophins: Potential Therapeutic Tools for the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) disrupts nerve pathways and can cause loss of function. However, some recovery can occur naturally, likely due to the central nervous system's ability to adapt. Neurotrophic factors, which promote neuronal plasticity, show promise for enhancing this plasticity and regeneration after SCI. Clinical treatments for SCI are limited to reducing secondary damage, as there are no methods to increase axon plasticity or regeneration. Strategies involve stabilizing the spine and minimizing secondary neural degeneration from factors like inflammation and ischemia. Obstacles to CNS regeneration include neuron-dependent factors like receptor expression and regeneration-associated genes, and neuron-independent factors like the absence of growth-promoting substrates and inhibitory proteins.

• 1
  Neurotrophins like NGF, BDNF, and NT-3 can promote the regeneration of specific neuronal populations after SCI. For example, NGF promotes sprouting of cholinergic motor axons, while BDNF supports regeneration of raphaespinal and rubrospinal axons.
• 2
  Gradients of NT-3 expression can induce chemotropic regeneration of sensory axons, allowing them to bridge the injury site and form synapses in appropriate target nuclei, though these new projections may not be fully functional.
• 3
  Peripheral conditioning lesions can enhance the regenerative potential of sensory neurons by modulating intrinsic signaling pathways and upregulating growth-associated genes like GAP-43.