Poulos Andrew M, Thompson Richard F
Neuroscience Program, University of Southern California, Los Angeles, CA 90082-2520, USA.
Integr Physiol Behav Sci. 2004 Apr-Jun;39(2):83-94. doi: 10.1007/BF02734274.
A large body of evidence indicates that the cerebellum is essential for the acquisition, retention, and expression of the standard delay conditioned eyeblink response and that the basic memory trace appears to be established in the anterior interpositus nucleus (IP). Adaptive timing of the conditioned response (CR) is a prominent feature of classical conditioning-the CR peaks at the time of onset of the unconditioned stimulus (US) over a wide range of CS-US interstimulus intervals (ISI). A key issue is whether this timing is established by the cerebellar circuitry or prior to the cerebellum. In this study timing of conditioned eyeblink responses established via electrical stimulation of the interpositus nucleus as a conditioned stimulus (CS) was analyzed prior to and following modification of the CS-US interval in well-trained rabbits. Consistent with previous results, learning under these conditions is very rapid and robust. The CR peak eyeblink latencies are initially timed to the US onset and adjust accordingly to lengthening or shortening of the CS-US interval, just as with peripheral CSs. The acquisition of conditioned eyeblink responses by direct electrical stimulation of the IP as a CS thus retains temporal flexibility following shifts in the CS-US delay, as found in standard classical eyeblink conditioning procedures.
大量证据表明，小脑对于标准延迟条件性眨眼反应的习得、保留和表达至关重要，并且基本记忆痕迹似乎在前间位核（IP）中建立。条件反应（CR）的适应性定时是经典条件反射的一个突出特征——在广泛的条件刺激-非条件刺激间隔（ISI）范围内，CR在非条件刺激（US）开始时达到峰值。一个关键问题是这种定时是由小脑回路建立的还是在小脑之前建立的。在本研究中，在训练有素的兔子中，在改变条件刺激-非条件刺激间隔之前和之后，分析了通过电刺激间位核作为条件刺激（CS）建立的条件性眨眼反应的定时。与先前的结果一致，在这些条件下学习非常迅速且稳固。CR峰值眨眼潜伏期最初与US开始时间同步，并随着条件刺激-非条件刺激间隔的延长或缩短而相应调整，就像使用外周条件刺激时一样。因此，通过直接电刺激IP作为条件刺激来习得条件性眨眼反应，在条件刺激-非条件刺激延迟发生变化后仍保持时间灵活性，这与标准经典眨眼条件反射程序中的情况相同。
