Perkel D H, Perkel D J
Brain Res. 1985 Jan 28;325(1-2):331-5. doi: 10.1016/0006-8993(85)90334-8.
Dendritic spines have been increasingly implicated as sites for neuronal plasticity. Earlier-theoretical studies of dendritic-spine function have assumed passive membrane, and have consequently predicted that postsynaptic potentials in the dendrite are attenuated when the synapse is located on the spine head rather than on the dendritic shaft. Our studies show that active membrane in the spine head (e.g. voltage-dependent Na+ or Ca2+ channels) can produce amplification rather than attenuation of the postsynaptic potential. The presence and amount of amplification depend on the density of active channels and on the spine-neck resistance. For a given type of spine head, there is an optimal spine-neck resistance; a given change in neck resistance can therefore either increase or decrease the amplitude of postsynaptic potentials. These results support the idea that spines mediate synaptic plasticity and suggest a variety of modulatory mechanisms.
树突棘越来越被认为是神经元可塑性的位点。早期关于树突棘功能的理论研究假定膜是被动的，因此预测当突触位于棘突头部而非树突干上时，树突中的突触后电位会衰减。我们的研究表明，棘突头部的活性膜（如电压依赖性钠通道或钙通道）可产生突触后电位的放大而非衰减。放大的存在和程度取决于活性通道的密度和棘突颈部电阻。对于给定类型的棘突头部，存在一个最佳的棘突颈部电阻；因此，颈部电阻的给定变化可以增加或减小突触后电位的幅度。这些结果支持了棘突介导突触可塑性的观点，并提示了多种调节机制。
