Poznanski R R
Neural Networks Research Group, Faculty of Computer Science & Information Technology, University of Malaya, 50603 Kuala Lumpur, Malaysia.
J Integr Neurosci. 2010 Sep;9(3):299-335. doi: 10.1142/s0219635210002457.
Optical imaging of dendritic calcium signals provided evidence of starburst amacrine cells exhibiting calcium bias to somatofugal motion. In contrast, it has been impractical to use a dual-patch clamp technique to record membrane potentials from both proximal dendrites and distal varicosities of starburst amacrine cells in order to unequivocally prove that they are directionally sensitive to voltage, as was first suggested almost two decades ago. This paper aims to extend the passive cable model to an active cable model of a starburst amacrine cell that is intrinsically dependent on the electrical properties of starburst amacrine cells, whose various macroscopic currents are described quantitatively. The coupling between voltage and calcium just below the membrane results in a voltage-calcium system of coupled nonlinear Volterra integral equations whose solutions must be integrated into a prescribed model for example, for a synaptic couplet of starburst amacrine cells. Networks of starburst amacrine cells play a fundamental role in the retinal circuitry underlying directional selectivity. It is suggested that the dendritic plexus of starburst amacrine cells provides the substrate for the property of directional selectivity, while directional selectivity is a property of the exclusive layerings and confinement of their interconnections within the sublaminae of the inner plexiform layer involving cone bipolar cells and directionally selective ganglion cells.
树突状钙信号的光学成像提供了证据，表明无长突星形细胞对离体细胞运动表现出钙偏向性。相比之下，正如近二十年前首次提出的那样，使用双膜片钳技术记录无长突星形细胞近端树突和远端曲张体的膜电位，以明确证明它们对电压具有方向敏感性，这是不切实际的。本文旨在将无源电缆模型扩展为无长突星形细胞的有源电缆模型，该模型本质上依赖于无长突星形细胞的电学特性，其各种宏观电流已被定量描述。膜下电压与钙之间的耦合导致了一个由耦合非线性沃尔泰拉积分方程组成的电压 - 钙系统，其解必须被整合到一个规定的模型中，例如用于无长突星形细胞的突触对。无长突星形细胞网络在方向选择性的视网膜回路中起着基本作用。有人认为，无长突星形细胞的树突丛为方向选择性特性提供了基础，而方向选择性是其在涉及视锥双极细胞和方向选择性神经节细胞的内网状层亚层内独特分层和连接限制的特性。
