- 作者: Wen-Pin Chen Yang-Chyuan Chang Sung-Tsang Hsieh
- 作者服務機構: Departments of Anatomy and Neurology, National Taiwan University College of Medicine, Taipei, Taiwan
- 中文摘要: --
- 英文摘要: Neurotrophins are target-derived trophic factors essen-tial for the survival and maintenance of neurons, Amongthese, nerve growth factor(NGF)and neurotrophin-3(NT-3) are particularly important for sensory neurons.The actions of neurotrophins are through the p75 low-affinity receptor and the high-affinity receptor tyrosinekinase (trk). Each neurotrophin has its preferred receptor,i.e. trkA for NGF, and trkC for NT-3. The primary sensoryneurons in the dorsal root ganglion are classified intotwo categories, namely, the large and small sensory neu-rons based on their size. The large sensory neurons withthe expression of trkC depend on NT-3 for developmentand subserve the function of position sensations. Someof the small sensory neurons express trkA and are NGF-dependent. They are responsible for nociceptive sensa-tion, the detection of painful and thermal stimuli. A moreintriguing observation is the bidirectional interactionsbetween nociceptive nerves and their target, the skin.The peripheral processes of small sensory neurons in-nervate the epidermis of the skin as 'free nerve endings'.In denervated skin, there is a drastic reduction in the epi-dermal thickness, a finding corroborated bythe phenom-enon of trophic change, the shining and thinning of theskin, in the disorders of peripheral nerves. The perfor-mance of animals with peripheral nerve disorders im-proved after administration of neurotrophic factors.Based on these results, the therapeutic potentials of neu-rotrophic factors in human are under investigation.
- 中文關鍵字: --
- 英文關鍵字: Neurotrophin. Receptor tyrosine kinase. Sensory neurons. Skin innervation. Nerve growth factor. Keratinocvtes. Nerve-target interaction