Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD), UNSE-CONICET, El Zanjón, Santiago del Estero, Argentina.
Sci Rep. 2019 Aug 27;9(1):12398. doi: 10.1038/s41598-019-48677-1.
Microtubules (MTs) are cytoskeletal structures that play a central role in a variety of cell functions including cell division and cargo transfer. MTs are also nonlinear electrical transmission lines that produce and conduct electrical oscillations elicited by changes in either electric field and/or ionic gradients. The oscillatory behavior of MTs requires a voltage-sensitive gating mechanism to enable the electrodiffusional ionic movement through the MT wall. Here we explored the electrical response of non-oscillating rat brain MT sheets to square voltage steps. To ascertain the nature of the possible gating mechanism, the electrical response of non-oscillating rat brain MT sheets (2D arrays of MTs) to square pulses was analyzed under voltage-clamping conditions. A complex voltage-dependent nonlinear charge movement was observed, which represented the summation of two events. The first contribution was a small, saturating, voltage-dependent capacitance with a maximum charge displacement in the range of 4 fC/μm. A second, major contribution was a non-saturating voltage-dependent charge transfer, consistent with the properties of a multistep memristive device. The memristive capabilities of MTs could drive oscillatory behavior, and enable voltage-driven neuromorphic circuits and architectures within neurons.
微管（MTs）是细胞骨架结构，在包括细胞分裂和货物转运在内的各种细胞功能中发挥核心作用。MTs 也是非线性的电传输线，可产生和传导由电场和/或离子梯度变化引起的电振荡。MTs 的振荡行为需要一个电压敏感的门控机制，以允许离子通过 MT 壁进行电扩散运动。在这里，我们研究了非振荡大鼠脑 MT 片对方波电压阶跃的电响应。为了确定可能的门控机制的性质，在电压钳制条件下分析了非振荡大鼠脑 MT 片（MT 的二维阵列）对方波脉冲的电响应。观察到一种复杂的电压依赖性非线性电荷移动，它代表了两个事件的总和。第一个贡献是一个小的、饱和的、电压依赖性电容，最大电荷位移范围在 4 fC/μm 左右。第二个主要贡献是一种非饱和的电压依赖性电荷转移，与多步忆阻器件的特性一致。MTs 的忆阻能力可以驱动振荡行为，并在神经元内实现电压驱动的神经形态电路和架构。
