Ballesteros-Yáñez I, Benavides-Piccione R, Elston G N, Yuste R, DeFelipe J
Cajal Institute (CSIC), Avda Dr Arce 37, 28002 Madrid, Spain.
Neuroscience. 2006;138(2):403-9. doi: 10.1016/j.neuroscience.2005.11.038. Epub 2006 Feb 2.
Dendritic spines of pyramidal cells are the main postsynaptic targets of cortical excitatory synapses and as such, they are fundamental both in neuronal plasticity and for the integration of excitatory inputs to pyramidal neurons. There is significant variation in the number and density of dendritic spines among pyramidal cells located in different cortical areas and species, especially in primates. This variation is believed to contribute to functional differences reported among cortical areas. In this study, we analyzed the density of dendritic spines in the motor, somatosensory and visuo-temporal regions of the mouse cerebral cortex. Over 17,000 individual spines on the basal dendrites of layer III pyramidal neurons were drawn and their morphologies compared among these cortical regions. In contrast to previous observations in primates, there was no significant difference in the density of spines along the dendrites of neurons in the mouse. However, systematic differences in spine dimensions (spine head size and spine neck length) were detected, whereby the largest spines were found in the motor region, followed by those in the somatosensory region and those in visuo-temporal region.
锥体细胞的树突棘是皮质兴奋性突触的主要突触后靶点，因此，它们在神经元可塑性以及锥体细胞兴奋性输入的整合中都至关重要。位于不同皮质区域和物种（尤其是灵长类动物）的锥体细胞之间，树突棘的数量和密度存在显著差异。这种差异被认为导致了不同皮质区域之间所报道的功能差异。在本研究中，我们分析了小鼠大脑皮质运动区、体感区和视颞区的树突棘密度。绘制了超过17,000个位于III层锥体细胞基底树突上的单个树突棘，并比较了这些皮质区域之间它们的形态。与之前在灵长类动物中的观察结果相反，小鼠神经元树突上的树突棘密度没有显著差异。然而，检测到树突棘尺寸（棘头大小和棘颈长度）存在系统性差异，其中最大的树突棘出现在运动区，其次是体感区和视颞区的树突棘。
