Highlight Semaphorin 3A is a classically known axonal guidance cue that mediates axonal growth cone repulsion and collapse.Recent works,however,suggest that it may have the apparently diametrically opposite activity o...Highlight Semaphorin 3A is a classically known axonal guidance cue that mediates axonal growth cone repulsion and collapse.Recent works,however,suggest that it may have the apparently diametrically opposite activity of promoting neuronal regeneration.展开更多
It is well established that guidance of axons during neuronal development is regulated by a variety of extracellular signals,governing cytoskeletal dynamics in growth cones.The actin and microtubule（MT）cytoskeleton ...It is well established that guidance of axons during neuronal development is regulated by a variety of extracellular signals,governing cytoskeletal dynamics in growth cones.The actin and microtubule（MT）cytoskeleton have both been shown to play important roles.However,a growing body of work suggests that a critical issue is the proper coordination of changes within these two major cytoskeletal systems（reviewed in Cammara-ta et al., 2016）.展开更多
Cannabis has a detrimental impact on the developing nervous system. Therefore, regular consumption of cannabis by pregnant and lactating woman poses a potential risk to neuronal growth in fetuses and infants. Indeed, ...Cannabis has a detrimental impact on the developing nervous system. Therefore, regular consumption of cannabis by pregnant and lactating woman poses a potential risk to neuronal growth in fetuses and infants. Indeed, endogenous cannabis-like molecules called endocannabinoids regulate many physiological processes, including neurogenesis, axon guidance, and synaptic plasticity through CB1 receptors. To investigate the physiological role of CB1 receptors on peripheral sensory nerve growth, the endocannabinoid 2-arachidonoyl glycerol was added to cultured chick dorsal root ganglion neurons. This compound inhibited neurite elongation and induced growth cone collapse in a dose- and time-dependent manner. These data suggest that caution should be exercised regarding maternal cannabis use during pregnancy. Because ectopic sprouting and abnormal neuronal network connections are considered to be a cause of neuropathic pain, our current data imply an additional role of endocannabinoids as inhibitors of the formation of pain-maintenance networks.展开更多
Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth...Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.展开更多
Proteoglycans in the central nervous system play integral roles as ＂traffic signals＂ for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central n...Proteoglycans in the central nervous system play integral roles as ＂traffic signals＂ for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central nervous system. In this review, the structures of proteoglycans and the evidence suggesting their involvement in the response following spinal cord injury are presented. The review further describes the methods routinely used to determine the effect proteoglycans have on neurite outgrowth. The effects of proteoglycans on neurite outgrowth are not completely understood as there is disagreement on what component of the molecule is interacting with growing neurites and this ambiguity is chronicled in an historical context. Finally, the most recent findings suggesting possible receptors, interactions, and sulfation patterns that may be important in eliciting the effect of proteoglycans on neurite outgrowth are discussed. A greater understanding of the proteoglycan-neurite interaction is necessary for successfully promoting regeneration in the iniured central nervous system.展开更多
文摘Highlight Semaphorin 3A is a classically known axonal guidance cue that mediates axonal growth cone repulsion and collapse.Recent works,however,suggest that it may have the apparently diametrically opposite activity of promoting neuronal regeneration.
基金supported by the Hungarian Science Foundation(OTKA)(K109330 to JM)the Hungarian Brain Research Program(KTIA_NAP_13-2-2014-0007 to JM)+1 种基金the National Research,Development and Innovation Office(GINOP-2.3.2-15-2016-00001 and GINOP-2.3.2-15-2016-00032 to JM)by an MTA Postdoctoral Fellowship(to IF)
文摘It is well established that guidance of axons during neuronal development is regulated by a variety of extracellular signals,governing cytoskeletal dynamics in growth cones.The actin and microtubule（MT）cytoskeleton have both been shown to play important roles.However,a growing body of work suggests that a critical issue is the proper coordination of changes within these two major cytoskeletal systems（reviewed in Cammara-ta et al., 2016）.
文摘Cannabis has a detrimental impact on the developing nervous system. Therefore, regular consumption of cannabis by pregnant and lactating woman poses a potential risk to neuronal growth in fetuses and infants. Indeed, endogenous cannabis-like molecules called endocannabinoids regulate many physiological processes, including neurogenesis, axon guidance, and synaptic plasticity through CB1 receptors. To investigate the physiological role of CB1 receptors on peripheral sensory nerve growth, the endocannabinoid 2-arachidonoyl glycerol was added to cultured chick dorsal root ganglion neurons. This compound inhibited neurite elongation and induced growth cone collapse in a dose- and time-dependent manner. These data suggest that caution should be exercised regarding maternal cannabis use during pregnancy. Because ectopic sprouting and abnormal neuronal network connections are considered to be a cause of neuropathic pain, our current data imply an additional role of endocannabinoids as inhibitors of the formation of pain-maintenance networks.
基金supported by National Key R&D Program of China(2017YFD0600601)
文摘Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.
基金supported by the NIH(NS53470)the Kentucky Spinal Cord and Head Injury Research Trust(#10-11A)the Department of Defense,CDMRP(SC090248/W81XWH-10-1-0778)
文摘Proteoglycans in the central nervous system play integral roles as ＂traffic signals＂ for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central nervous system. In this review, the structures of proteoglycans and the evidence suggesting their involvement in the response following spinal cord injury are presented. The review further describes the methods routinely used to determine the effect proteoglycans have on neurite outgrowth. The effects of proteoglycans on neurite outgrowth are not completely understood as there is disagreement on what component of the molecule is interacting with growing neurites and this ambiguity is chronicled in an historical context. Finally, the most recent findings suggesting possible receptors, interactions, and sulfation patterns that may be important in eliciting the effect of proteoglycans on neurite outgrowth are discussed. A greater understanding of the proteoglycan-neurite interaction is necessary for successfully promoting regeneration in the iniured central nervous system.
