Figure 11.
Neurotrophic factor signaling pathway. NGF has a high affinity with TrkA and facilitates differentiation and survival of neurons.126 BDNF has a high affinity with TrkB and enhances axonal growth and survival of neurons.102,127 NT-3 has a high affinity with TrkC and promotes the survival of neurons.126 CNTF signals, via the JAK/STAT pathway, have been widely and successfully used to facilitate the regeneration of retinal ganglion cell axons in adult rats.128 FGF signals through the PI3K/AKT pathway and stimulates proliferation, angiogenesis, and survival of neurons.129 GDNF can send signals through RET-independent or RET-dependent pathways. The latter can promote neuronal differentiation, survival, and migration.124,130 CNTF, ciliary neurotrophic factor; FGF, fibroblast growth factor; GDNF, glial cell-derived neurotrophic factor; JAK/STAT, Janus kinase/signal transducers and activators of transcription; NGF, nerve growth factor; NT-3, neurotrophin-3; PI3K/AKT, phosphoinositide 3 kinase/serine–threonine kinase; TrkA, tropomyosin receptor kinase A; TrkB, tropomyosin receptor kinase B; TrkC, tropomyosin receptor kinase C.