Kashimori Y, Goto M, Kambara T
Department of Applied Physics and Chemistry, University of Electro-Communications, Tokyo, Japan.
Biophys J. 1996 Jun;70(6):2513-26. doi: 10.1016/S0006-3495(96)79823-5.
To clarify the microscopic mechanisms by which P- and T-receptors encode amplitude modulation and zero crossing time of jamming signals, we present a model of P- and T-receptors based on their physiological and anatomical properties. The model consists of a receptor cell, supporting cells, and an afferent nerve fiber. The basal membrane of the receptor cell includes voltage-sensitive Ca2+ channels, Ca(2+)-activated K+ channels, and leak channels of Na+, K+, and Cl-. The driving force of potential change under stimulation is generated by the voltage-sensitive Ca2+ channels, and the suppressing force of the change is generated by Ca(2+)-activated K+ channels. It has been shown that in T-receptor cells the driving force is much stronger than the suppressing force, whereas in P-receptor cells the driving force is comparable with the suppressing force. The difference in various kinds of response properties between P- and T-receptors have been consistently explained based on the difference in the relative strengths of the driving and suppressing forces between P- and T-receptor cells. The response properties considered are encoding function, probability of firing of afferent nerve, pattern of damped oscillation, shape of tuning curves, values of the optimum frequency, and response latency.
为了阐明P受体和T受体编码干扰信号的调幅和过零时间的微观机制，我们基于P受体和T受体的生理和解剖特性提出了一个模型。该模型由一个受体细胞、支持细胞和一条传入神经纤维组成。受体细胞的基底膜包括电压敏感的Ca2+通道、Ca(2+)激活的K+通道以及Na+、K+和Cl-的泄漏通道。刺激下电位变化的驱动力由电压敏感的Ca2+通道产生，而变化的抑制力由Ca(2+)激活的K+通道产生。研究表明，在T受体细胞中，驱动力比抑制力强得多，而在P受体细胞中，驱动力与抑制力相当。基于P受体细胞和T受体细胞之间驱动力和抑制力相对强度的差异，一直以来都能对P受体和T受体之间各种反应特性的差异作出解释。所考虑的反应特性包括编码功能、传入神经放电概率、阻尼振荡模式、调谐曲线形状、最佳频率值以及反应潜伏期。
