不同时间间隔对小脑条件反射性眨眼的影响
Influence of Various Temporal Recoding on Pavlovian Eyeblink Conditioning in The Cerebellum
摘要：
我们认为巴甫洛夫眨眼条件反射（EBC）通过重复呈现成对的条件刺激（音）和非条件刺激（喷气）。在小脑网络中，从高尔基体到颗粒细胞的连接概率$p_c$改变，研究了颗粒细胞的不同时间编码对EBC的影响。在最佳情况下的$p_c^*~(=0.029)$，个别颗粒细胞显示各种良好和不匹配的放电模式相对于非条件刺激。然后，这些不同的重新编码的信号通过平行纤维（PF）馈送到浦肯野细胞（PC）。在匹配良好的PF-PC突触的情况下，它们的突触权重通过强长时程抑制（LTD）被强烈抑制。另一方面，几乎没有LTD发生的不匹配的PF-PC突触。这种在PF-PC突触上的“有效”抑制有效地协调PC的放电，然后对小脑核神经元进行有效的抑制协调[引起条件反应（CR;眨眼）]。当学习试验通过阈值时，CR的获取开始。在这种情况下，CR的定时度${\cal T}_d$由于存在起定时保护屏障作用的不匹配点火组而变得良好。随着试验的进一步增加，CR的强度$\cal S$（对应于眼睑闭合幅度）由于匹配良好的击发组中的强LTD而增加。因此，随着学习试验的增加，用于CR的（总体）学习效率程度${\cal L}_e$（考虑CR的定时和强度）增加，并且最终变得饱和。通过改变$p_c^*$的$p_c$，我们还研究了各种时间编码对EBC的影响。因此，它被发现，更多的时间编码的多样性，更有效的学习巴甫洛夫EBC。
英文摘要：
We consider the Pavlovian eyeblink conditioning (EBC) via repeated presentation of paired conditioned stimulus (tone) and unconditioned stimulus (airpuff). The influence of various temporal recoding of granule cells on the EBC is investigated in a cerebellar network where the connection probability $p_c$ from Golgi to granule cells is changed. In an optimal case of $p_c^*~(=0.029)$, individual granule cells show various well- and ill-matched firing patterns relative to the unconditioned stimulus. Then, these variously-recoded signals are fed into the Purkinje cells (PCs) through parallel-fibers (PFs). In the case of well-matched PF-PC synapses, their synaptic weights are strongly depressed through strong long-term depression (LTD). On the other hand, practically no LTD occurs for the ill-matched PF-PC synapses. This type of "effective" depression at the PF-PC synapses coordinates firings of PCs effectively, which then make effective inhibitory coordination on cerebellar nucleus neuron [which elicits conditioned response (CR; eyeblink)]. When the learning trial passes a threshold, acquisition of CR begins. In this case, the timing degree ${\cal T}_d$ of CR becomes good due to presence of the ill-matched firing group which plays a role of protection barrier for the timing. With further increase in the trial, strength $\cal S$ of CR (corresponding to the amplitude of eyelid closure) increases due to strong LTD in the well-matched firing group. Thus, with increasing the learning trial, the (overall) learning efficiency degree ${\cal L}_e$ (taking into consideration both timing and strength of CR) for the CR is increased, and eventually it becomes saturated. By changing $p_c$ from $p_c^*$, we also investigate the influence of various temporal recoding on the EBC. It is thus found that, the more various in temporal recoding, the more effective in learning for the Pavlovian EBC.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
