Bielajew C, Fouriezos G
Behav Brain Res. 1985 Sep-Oct;17(2):97-101. doi: 10.1016/0166-4328(85)90022-1.
The post-stimulation excitability of the substrate for brain stimulation reward in the mediodorsal thalamus was assessed using equal- and unequal-pulse procedures. In 3 rats, refractory periods were found to begin no earlier than 1 ms and to end as late as 10 ms. Using test (T) pulses 1.5 times the amplitude of condition (C) pulses, the contribution of absolute and relative refractory periods was determined in one subject. No change in the slope of the recovery function was obtained in this condition, suggesting that several populations of neurons with different absolute refractory periods compose the behaviorally relevant substrate. A large supernormal contribution, evaluated by increasing the C amplitude to 1.5T, occurred between 3 and 10 ms with a peak at 7.5 ms. These results suggest that mediodorsal thalamic self-stimulation is mediated by a wide range of small, probably unmyelinated fibers.
使用等脉冲和不等脉冲程序评估了丘脑背内侧中脑刺激奖赏底物的刺激后兴奋性。在3只大鼠中，发现不应期开始不早于1毫秒，结束最晚可达10毫秒。使用幅度为条件（C）脉冲1.5倍的测试（T）脉冲，在一个实验对象中确定了绝对不应期和相对不应期的贡献。在这种情况下，恢复函数的斜率没有变化，这表明具有不同绝对不应期的几个神经元群体构成了行为相关底物。通过将C幅度增加到1.5T评估，在3至10毫秒之间出现了较大的超常贡献，峰值出现在7.5毫秒。这些结果表明，丘脑背内侧的自我刺激是由广泛的小的、可能无髓鞘的纤维介导的。
