Neurotrophin action on sensory neurons in adults: an extension of the neurotrophic hypothesis

This brief review explores the action of neurotrophins on sensory neurons i n adults. Neutralization of neurotrophins in adults does not cause sensory neurons to die as it does in prenatal animals. Thus they are not required a s survival factors in adults. However, neurotrophins continue to play impor tant roles in the postnatal development of sensory neurons. They also exert strong effects on the anatomy and physiology of these fibers after axotomy in adults. Here we review of the effects of NT-3 on spindle afferent fiber s and NGF on nociceptive afferents and consider possible extension of the n eurotrophic hypothesis to adults. (C) 1999 International Association for th e Study of Pain. published by Elsevier Sceince B.V.