Uniform growth and neuronal integration.
Uniform growth and neuronal integration.
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均匀生长和神经元整合。
DOI：
10.1152/jn.1996.76.3.1850
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Edwards,DH
中科院分区：
文献类型：
--
作者：
Olsen,O;Nadim,F;Hill,AA;Edwards,DH
1. 分析了电缆方程，确定了两种均匀生长模式对神经元被动和主动整合特性的影响。2. 在均匀等电紧张生长过程中，所有神经元过程的直径都随着其长度增加的平方而增加，而神经元的特定电学性质和分支终端条件保持不变。通过分析归纳证明，对于任何神经元，均匀等电紧生长使各处的输入电导增加生长因子的立方，但使神经元内膜电位的主动和被动扩散保持不变。膜电压的扩散是不变的，因为这种生长模式使得细胞内各处的轴向电流和膜电流都以生长因子的立方增加。如果突触的突触后总电导随着树突膜面积的增加而增加，那么突触输入在等电张力较大的细胞中引起的反应与在较小的细胞中引起的反应相同。3. 在均匀等长生长过程中，所有过程的直径和长度以相同的因子增加，而特定的电学性质和分支终端条件保持不变。这种均匀生长的模式通过生长因子的平方增加了输入电导，并且还增加了细胞响应的衰减、延迟和低通滤波。电压衰减随着等长生长而增加，因为轴向电流与生长成正比，而膜电流与生长因子的平方成正比。等长生长降低了远端突触输入影响近端整合位点膜电位的能力，即使在突触电导增加以补偿输入电导增加之后也是如此。4. 这两种均匀生长模式有助于确定所有类型的均匀生长对神经元整合和反应的影响。
1. The cable equations were analyzed to determine the effects of two patterns of uniform growth on the passive and active integrative properties of neurons. 2. During uniform isoelectrotonic growth, the diameters of all neuronal processes increase as the square of their increase in length, while the specific electrical properties and branch terminal conditions of the neuron remain constant. An analytic inductive proof is given to show that, for any neuron, uniform isoelectrotonic growth increases the input conductance everywhere by the cube of the growth factor, but leaves the active and passive spread of membrane potential within the neuron unchanged. The spread of membrane voltage is unchanged because this pattern of growth enables both the axial and membrane currents everywhere in the cell to increase by the cube of the growth factor. Synaptic inputs would evoke the same responses in the isoelectrotonically larger cell as in the smaller cell if the total postsynaptic conductance of the synapse increased with the dendritic membrane area. 3. During uniform isometric growth, the diameter and lengths of all processes increase by the same factor, while the specific electrical properties and branch terminal conditions remain constant. This pattern of uniform growth increases the input conductance by the square of the growth factor, and also increases the attenuation, delay, and low-pass filtering of the cell's responses. Voltage attenuation increases with isometric growth because the axial current increases in proportion to growth, while the membrane current increases in proportion to the square of the growth factor. Isometric growth reduces the ability of distal synaptic inputs to affect the membrane potential at proximal integrating sites, even after the synaptic conductance has increased to compensate for the increased input conductance. 4. These two patterns of uniform growth help define the consequences of all types of uniform growth for neuronal integration and responsiveness.