Deller T, Mundel P, Frotscher M
Institute of Anatomy, University of Freiburg, Germany.
Hippocampus. 2000;10(5):569-81. doi: 10.1002/1098-1063(2000)10:5<569::AID-HIPO7>3.0.CO;2-M.
Dendritic spines are dynamic structures that rapidly remodel their shape and size. These morphological adaptations are regulated by changes in synaptic activity, and result from rearrangements of the postsynaptic cytoskeleton. A cytoskeletal molecule preferentially found in mature spines is the actin-associated protein synaptopodin. It is strongly expressed by spine-bearing neurons in the olfactory bulb, striatum, cerebral cortex, and hippocampus. In the hippocampus, principal cells express synaptopodin mRNA and sort the protein to the spine compartment. Within the spine microdomain, synaptopodin is preferentially located in the spine neck and is closely associated with the spine apparatus. On the basis of these data we hypothesize that synaptopodin could affect spine motility by bundling actin filaments in the spine neck. In addition, it could link the actin cytoskeleton of spines to intracellular calcium stores, i.e., the spine apparatus and the smooth endoplasmic reticulum.
树突棘是动态结构，其形状和大小会迅速重塑。这些形态学适应由突触活动的变化调节，是突触后细胞骨架重排的结果。一种在成熟棘中优先发现的细胞骨架分子是肌动蛋白相关蛋白突触素。它在嗅球、纹状体、大脑皮层和海马体中由有棘神经元强烈表达。在海马体中，主要细胞表达突触素mRNA并将该蛋白分选到棘区室。在棘微区内，突触素优先位于棘颈部，并与棘器紧密相关。基于这些数据，我们推测突触素可能通过捆绑棘颈部的肌动蛋白丝来影响棘的运动性。此外，它可能将棘的肌动蛋白细胞骨架与细胞内钙库，即棘器和平滑内质网连接起来。
