【摘 要】
：
Objective Axon-wrapping myelin sheath formed by oligodendrocytes(OLs)is essential for proper functions of the nervous system.Although much is known about the development and migration of OLs and its p
【机 构】
：
Department of Neurobiology and Key Laboratory of Molecular Neurobiology of Ministry of Education,Sec
【出 处】
：
第九届海内外华人神经科学家研讨会(The 9th Symposium for Chinese Neuroscientis
论文部分内容阅读
Objective Axon-wrapping myelin sheath formed by oligodendrocytes(OLs)is essential for proper functions of the nervous system.Although much is known about the development and migration of OLs and its progenitor cells in vitro and in vivo,how the myelin in the central nervous system(CNS)is dynamically formed is still unclear.Methods To examine the process of CNS myelination in vivo and underlying molecular mechanisms,we performed genetic manipulations and long-term time-lapse confocal imaging of the same OLs in the spinal cord of intact zebrafish larvae during 2-7 days post-fertilization(dpf)with intervals of 2-12 h.Results We find that,along the axon of Mauthner cells(M-axon),myelin sheaths exhibit anterior orientated extension,which is mediated by anterior-to-posterior decreasing gradient of Wnt signaling in the ventral spinal cord of zebrafish.Global or OL-specific down-regulation of Wnt signals impairs the directional extension of M-axon-wrapping myelin segments.Furthermore,local disruption of the Wnt gradient also reduces this directional preference.Additionally,Non-M-axon-wrapping myelin segments show anterior extension preference in the ventral but not dorsal spinal cord,mainly due to the fact that Wnt4b expression was only restricted to ventral.Moreover,by using F-actin to indicate the active lateral growth core of developing myelin segments,we find that it also shows anterior extending preference in mammalians spinal cord.Take together,our findings indicate that,after initial axon wrapping,anterior-to-posterior Wnt gradient in the ventral spinal cord enables directional extension of myelin sheaths,a process important for proper function of neural systems.Conclusion Our study reveals anterior directional extension of myelin segments as a novel process during myelination.
其他文献
Information about translations and rotations of the body is critical for complex selfmotion perception during spatial navigation.However,little is known about the nature and function of their converge
Neurotoxins are harmful to brain functions,especially interrupting memory processing.Hippocampal synaptic plasticity is supposed as models for memory processing.We and others reported the potential de
Papermulberry fruit is commonly used for patients with chronic cerebral circulatoryinsufficiency(CCCI),which has the function of the tonifying liver and kidney.The present study focused on the efficac
Recently,some studies demonstrated that neuron activity of the dorsal premotor cortex(PMd)showed selectivity for different hand gestures during planning period,which suggested that PMd is involved not
The pathogenesis of multiple chronic visceral pain syndromes,such as irritable bowel syndrome(IBS),is not well known,and as a result current therapies are not effective.The objective of this study was
We examined cortical plasticity in addicted human subjects and rats following Meth selfadministration(SA).We identified impairment of plasticity in both potentiation and depression directions in motor
Neuropathic pain following periphery injury or DRG injury is likely due to increased excitatory contacts between sympathetic nerves and dorsal root ganglia(DRG)neurons via sympathetic efferent nerve f
All moving objects generate sequential retinotopic activations representing a series of discrete locations in space and time(motion trajectory).Visual motion is fundamentally different from physical m
The somata of primary sensory neurons,including dorsal root ganglion(DRG)neurons,release neurotransmitters and neuropeptides.Following physiological action potentials,in addition to Ca2+-dependent sec
Chronic pain caused by peripheral inflammation has always been the difficulty for clinical treatment.Currently developed analgesic drugs from the endogenous analgesic substances,such as opioids and ca