Axonal motility and its modulation by activity are branch-type specific in the intact adult cerebellum (Neuron, 2007, 56:472-487)

報告日期: 2008/05/16
報告時間: 17:10/18:00
報告學生: 陳俊彥
講評老師: 黃阿敏

Axonal Motility and Its Modulation by Activity Are Branch-Type Specific in the Intact Adult Cerebellum

Neuron 56, 472–487, November 8, 2007

Speaker: 陳俊彥   Commentator: 黃阿敏老師

Place: 醫學院602教室   Date/Time: 2008/05/16 17:10-18:00


  In adult brain, structural plasticity of neuron still can be influenced by many conditions such as learning and sensory enrichment. Pervious studies using two-photon microscopy which can image the same neuronal structures repeatedly indicate that axons in neocortex are dynamic as dendritic spines. In order to know more about structural plasticity of axons, cerebellar climbing fibers (CFs) are chose as a model system. CFs are axons from inferior olivary nucleus with ascending and transverse branches. Fluorescent tracer injection and GFP expression were used to observe CFs with light microscopy, serial eclctromicroscopy and two-photon microscopy. Results of the observation include that (1) CFs transverse branches fail to form conventional synapses, (2) time-lapse imaging over hours or days show CFs transverse branches are more highly dynamic than ascending branches. Those results suggest that different branches of the same axon have branch-type specific structural plasticity. Harmaline can increase inferior olivary nucleus firing activity. After administration of harmaline, time-lapse imaging of CFs indicate dynamic changes of CFs transverse branches are completely suppressed by this firing. That means CFs axonal structural plasticity by activity is branch-type specific.




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