Passive cable properties and morphological correlates of neurones in the lateral geniculate nucleus of the cat.
Passive cable properties and morphological correlates of neurones in the lateral geniculate nucleus of the cat.
复制标题
猫外侧膝状核神经元的被动电缆特性和形态相关性。
DOI：
10.1113/jphysiol.1987.sp016435
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Sherman,SM
中科院分区：
文献类型：
--
作者：
Bloomfield,SA;Hamos,JE;Sherman,SM
1. 我们用猫的体内制剂研究了外侧膝状核中16个X细胞和12个Y细胞的无源电缆特性。根据Rall的公式（Rall, 1959a, 1969,1977），将细胞建模为等效圆柱体。我们将细胞内电流脉冲注入这些膝状神经元，并分析产生的电压瞬变以获得这些细胞的电缆参数。此外，54个具有生理特征的神经元被辣根过氧化物酶（HRP）标记并进行形态学分析。2. 对HRP标记的膝状神经元的分析表明，这些细胞的树突分支模式遵循3/2次方法则。也就是说，在每个分支点上，母枝的直径的3/2次方等于子枝的直径的3/2次方后的总和。此外，初步数据表明，从每个初级树突发出的树突末端发生在与体细胞相同的电紧张距离上。这些观察结果表明，X和Y细胞都满足将其树突乔木还原为等效圆柱体所需的几何约束。3. 我们发现，每个初级枝晶的直径与从它发出的叶柄的膜表面积之间存在很强的线性关系。我们利用这一关系推导出一种算法，通过了解体细胞和初级树突的直径，就可以确定X和Y细胞的体细胞和树突膜表面积。4. 膝状X细胞和Y细胞在静息膜电位+/‐20 mV范围内显示出线性的电流-电压关系。这意味着在电压暂态分析期间，我们可以很容易地保持在线性电压范围内。5. X细胞和Y细胞在许多电学性质上明显不同，包括输入电阻、膜时间常数和电紧张长度。X和Y细胞之间输入电阻的差异不能仅仅归因于X细胞的平均尺寸较小，但它也反映了X细胞更高的比膜电阻（Rm）。此外，X细胞的电紧张长度略大于Y细胞，但两种神经元类型的电紧张长度都大致为1。这表明，即使是位于这些细胞最远端的神经支配也会对它们的体细胞和轴突反应产生相当大的影响。（摘要删节为400字）
1. We used an in vivo preparation of the cat to study the passive cable properties of sixteen X and twelve Y cells in the lateral geniculate nucleus. Cells were modelled as equivalent cylinders according to Rall's formulations (Rall, 1959a, 1969, 1977). We injected intracellular current pulses into these geniculate neurones, and we analysed the resulting voltage transients to obtain the cable parameters of these cells. In addition, fifty‐four physiologically characterized neurones were labelled with horseradish peroxidase (HRP) and analysed morphologically. 2. Analysis of HRP‐labelled geniculate neurones showed that the dendritic branching pattern of these cells adheres closely to the 3/2 power rule. That is, at each branch point, the diameter of the parent branch raised to the 3/2 power equals the sum of the diameters of the daughter dendrites after each is raised to the 3/2 power. Furthermore, preliminary data indicate that the dendritic terminations emanating from each primary dendrite occur at the same electrotonic distance from the soma. These observations suggest that both X and Y cells meet the geometric constraints necessary for reduction of their dendritic arbors into equivalent cylinders. 3. We found a strong linear relationship between the diameter of each primary dendrite and the membrane surface area of the arbor emanating from it. We used this relationship to derive an algorithm for determining the total somatic and dendritic membrane surface area of an X and Y cell simply from knowledge of the diameters of its soma and primary dendrites. 4. Both geniculate X and Y cells display current‐voltage relationships that were linear within +/‐ 20 mV of the resting membrane potential. This meant that we could easily remain within the linear voltage range during the voltage transient analyses. 5. X and Y cells clearly differ in terms of many of their electrical properties, including input resistance, membrane time constant and electrotonic length. The difference in input resistance between X and Y cells cannot be attributed solely to the smaller average size of X cells, but it also reflects a higher specific membrane resistance (Rm) of the X cells. Furthermore, X cells exhibit electrotonic lengths slightly larger than those of Y cells, but both neuronal types display electrotonic lengths of roughly 1. This indicates that even the most distally located innervation to these cells should have considerable influence on their somatic and axonal responses.(ABSTRACT TRUNCATED AT 400 WORDS)