IONIC MECHANISMS FOR INTRINSIC SLOW OSCILLATIONS IN THALAMIC RELAY NEURONS
IONIC MECHANISMS FOR INTRINSIC SLOW OSCILLATIONS IN THALAMIC RELAY NEURONS
复制标题
DOI：
10.1016/s0006-3495(93)81190-1
复制
发表时间：
1993-10-01
影响因子：
3.4
通讯作者：
SEJNOWSKI, TJ
中科院分区：
文献类型：
--
作者：
DESTEXHE, A;BABLOYANTZ, A;SEJNOWSKI, TJ
用Hodgkin-Huxley模型研究了单个丘脑皮层神经元的振荡特性，该模型包括Ca ~（2+）扩散、低阈值Ca ~（2+）电流（I（T））和超极化激活内向电流（I（h））。I（h）由细胞内Ca ~（2+）调节的双激活动力学模型。该模型表现出由1-25秒的缓慢振荡（3.5-4 Hz）的爆发，由长的沉默期（4-20 s）分开的盈亏振荡。在振荡阶段，Ca ~（2+）的进入逐渐移动I（h）的激活函数，终止振荡。在没有Ca ~（2+）调节I（h）的情况下，从I（T）、I（h）和慢K ~+电流的组合中也观察到类似类型的上升和下降振荡。奇异近似表明，对于这两个模型，激活变量的I（h）控制丘脑皮层细胞的动力学。在相平面图中对系统的动力学分析表明，当I（h）在稳定和振荡分支之间交替夹带系统时，会产生盈亏振荡。
The oscillatory properties of single thalamocortical neurons were investigated by using a Hodgkin-Huxley-like model that included Ca2+ diffusion, the low-threshold Ca2+ current (I(T)) and the hyperpolarization-activated inward current I(h)). I(h) was modeled by double activation kinetics regulated by intracellular Ca2+. The model exhibited waxing and waning oscillations consisting of 1-25-s bursts of slow oscillations (3.5-4 Hz) separated by long silent periods (4-20 s). During the oscillatory phase, the entry of Ca2+ progressively shifted the activation function of I(h), terminating the oscillations. A similar type of waxing and waning oscillation was also observed, in the absence of Ca2+ regulation of I(h), from the combination of I(T), I(h), and a slow K+ current. Singular approximation showed that for both models, the activation variables of I(h) controlled the dynamics of thalamocortical cells. Dynamical analysis of the system in a phase plane diagram showed that waxing and waning oscillations arose when I(h) entrained the system alternately between stationary and oscillating branches.