Anomalous diffusion in Purkinje cell dendrites caused by spines
Anomalous diffusion in Purkinje cell dendrites caused by spines
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DOI：
10.1016/j.neuron.2006.10.025
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发表时间：
2006-11-22
期刊：
影响因子：
16.2
通讯作者：
Augustine, George J.
中科院分区：
文献类型：
--
作者：
Santamaria, Fidel;Wils, Stefan;Augustine, George J.
我们结合局部光解的笼状化合物与荧光成像可视化小脑浦肯野细胞树突内的分子扩散。扩散的体积标记物，荧光素葡聚糖，多刺树突内的扩散是非常缓慢的比较，其扩散在光滑的树突。计算机模拟表明，这种延迟是由于瞬态捕获的分子内的树突棘，产生异常扩散。我们研究了脊陷对突触第二信使Ca ~（2+）和1，4，5-三磷酸肌醇（IP_3）扩散的影响。IP 3的扩散受到树突棘存在的强烈影响，而Ca 2+被迅速去除，以至于它不能扩散得足够远而被捕获。我们得出结论，树突棘的一个重要功能可能是捕获化学信号，从而在树突内产生缓慢的异常扩散。
We combined local photolysis of caged compounds with fluorescence imaging to visualize molecular diffusion within dendrites of cerebellar Purkinje cells. Diffusion of a volume marker, fluorescein dextran, within spiny dendrites was remarkably slow in comparison to its diffusion in smooth dendrites. Computer simulations indicate that this retardation is due to a transient trapping of molecules within dendritic spines, yielding anomalous diffusion. We considered the influence of spine trapping on the diffusion of calcium ions (Ca2+) and inositol-1, 4,5-triphospate (IP3) two synaptic second messengers. Diffusion Of IP3 was strongly influenced by the presence of dendritic spines, while Ca2+ was removed so rapidly that it could not diffuse far enough to be trapped. We conclude that an important function of dendritic spines may be to trap chemical signals and thereby create slowed anomalous diffusion within dendrites.