Brain-derived neurotrophic factor（BDNF） plays an important role in neurodevelopment,synaptic plasticity,learning and memory,and in preventing neurodegeneration.Despite decades of investigations into downstream signa...Brain-derived neurotrophic factor（BDNF） plays an important role in neurodevelopment,synaptic plasticity,learning and memory,and in preventing neurodegeneration.Despite decades of investigations into downstream signaling cascades and changes in cellular processes,the mechanisms of how BDNF reshapes circuits in vivo remain unclear.This informational gap partly arises from the fact that the bulk of studies into the molecular actions of BDNF have been performed in dissociated neuronal cultures,while the majority of studies on synaptic plasticity,learning and memory were performed in acute brain slices or in vivo.A recent study by Bowling-Bhattacharya et al.,measured the proteomic changes in acute adult hippocampal slices following treatment and reported changes in proteins of neuronal and non-neuronal origin that may in concert modulate synaptic release and secretion in the slice.In this paper,we place these findings into the context of existing literature and discuss how they impact our understanding of how BDNF can reshape the brain.展开更多
The axonal compartment of developing neurons and mature peripheral nervous system （PNS） neurons has the capacity to locally synthesize proteins. Axonally-synthesized proteins have been shown to facilitate axonal pat...The axonal compartment of developing neurons and mature peripheral nervous system （PNS） neurons has the capacity to locally synthesize proteins. Axonally-synthesized proteins have been shown to facilitate axonal pathfinding and maintenance in developing central nervous system （CNS） and PNS neurons, and to facilitate the regeneration of mature PNS neurons. RNA-profiling studies of the axons of cultured neurons have shown a surprisingly complex population of mRNAs that encode proteins for a myriad of functions. Although classic-appearing rough endoplasmic reticulum （RER）, smooth endoplasmic reticulum （ER） and Golgi apparatus have not been documented in axons by ultrastructural studies, axonal RNA profiling studies show several membrane and secreted protein-encoding mRNAs whose translation products would need access to a localized secretory mechanism. We previously showed that the axons of cultured neurons contain functional equivalents of RER and Golgi apparatus. Here, we show that markers for the signal-recognition particle, RER, ER, and Golgi apparatus are present in PNS axons in vivo. Co-localization of these proteins mirrors that seen for cultured axons where locally-translated proteins are localized to the axoplasmic membrane. Moreover, nerve injury increases the levels and/or aggregation of these proteins, suggesting that the regenerating axon has an increased capacity for membrane targeting of locally synthesized proteins.展开更多
基金supported by NIH grants NS034007 and NS047384supported by NIH grants NS21072,and HD23315supported by funds from the Department of Biotechnology,Government of India and the Shanta Wadhwani Foundation
文摘Brain-derived neurotrophic factor（BDNF） plays an important role in neurodevelopment,synaptic plasticity,learning and memory,and in preventing neurodegeneration.Despite decades of investigations into downstream signaling cascades and changes in cellular processes,the mechanisms of how BDNF reshapes circuits in vivo remain unclear.This informational gap partly arises from the fact that the bulk of studies into the molecular actions of BDNF have been performed in dissociated neuronal cultures,while the majority of studies on synaptic plasticity,learning and memory were performed in acute brain slices or in vivo.A recent study by Bowling-Bhattacharya et al.,measured the proteomic changes in acute adult hippocampal slices following treatment and reported changes in proteins of neuronal and non-neuronal origin that may in concert modulate synaptic release and secretion in the slice.In this paper,we place these findings into the context of existing literature and discuss how they impact our understanding of how BDNF can reshape the brain.
基金supported by a grant from the Paralyzed Veterans Association (PVA # 2442)
文摘The axonal compartment of developing neurons and mature peripheral nervous system （PNS） neurons has the capacity to locally synthesize proteins. Axonally-synthesized proteins have been shown to facilitate axonal pathfinding and maintenance in developing central nervous system （CNS） and PNS neurons, and to facilitate the regeneration of mature PNS neurons. RNA-profiling studies of the axons of cultured neurons have shown a surprisingly complex population of mRNAs that encode proteins for a myriad of functions. Although classic-appearing rough endoplasmic reticulum （RER）, smooth endoplasmic reticulum （ER） and Golgi apparatus have not been documented in axons by ultrastructural studies, axonal RNA profiling studies show several membrane and secreted protein-encoding mRNAs whose translation products would need access to a localized secretory mechanism. We previously showed that the axons of cultured neurons contain functional equivalents of RER and Golgi apparatus. Here, we show that markers for the signal-recognition particle, RER, ER, and Golgi apparatus are present in PNS axons in vivo. Co-localization of these proteins mirrors that seen for cultured axons where locally-translated proteins are localized to the axoplasmic membrane. Moreover, nerve injury increases the levels and/or aggregation of these proteins, suggesting that the regenerating axon has an increased capacity for membrane targeting of locally synthesized proteins.
