Bielajew C, Jurgens S, Fouriezos G
Behav Brain Res. 1987 Jun;24(3):233-41. doi: 10.1016/0166-4328(87)90061-1.
The post-stimulation excitability characteristics of neurons mediating the rewarding effects of electrical stimulation of the medial forebrain bundle were behaviorally assessed at 5 different pulse durations. Recovery from refractoriness was inferred from the results of double-pulse tests in which the interval between conditioning (C) and test (T) pulses of equal amplitude was varied. Pulses of 0.1-0.5 ms had little effect on the time course of recovery which ranged from 0.4 to about 1.5 ms in each animal. In some subjects, however, complete recovery from refractoriness was significantly delayed with 1- and 2-ms pulses, with as much as a tripling in the C-T interval at which recovery approached asymptotic levels. This effect appeared to be placement-specific and was well correlated with the threshold charge, which ranged from 0.5 to 1.3 microC. The highest charge values were obtained in those subjects in which longer pulses displaced the refractory period profile towards a slower recovery; the electrode tips in this group were located in more anterior positions than those subjects in which pulse duration had no effect on recovery from refractoriness. It appears that at some placements slowly recovering elements can contribute to the circuitry underlying brain-stimulation reward when suitable stimulation parameters are employed.
在内侧前脑束电刺激奖赏效应的介导神经元中，于5种不同脉冲持续时间下对刺激后兴奋性特征进行了行为学评估。通过双脉冲测试结果推断不应期恢复情况，其中等幅的条件（C）脉冲与测试（T）脉冲之间的间隔是变化的。0.1 - 0.5毫秒的脉冲对恢复的时间进程影响很小，每只动物的恢复时间在0.4至约1.5毫秒之间。然而，在一些实验对象中，1毫秒和2毫秒的脉冲使从不应期完全恢复显著延迟，恢复接近渐近水平时的C - T间隔增加了两倍之多。这种效应似乎具有位置特异性，并且与阈值电荷密切相关，阈值电荷范围为0.5至1.3微库仑。在那些较长脉冲使不应期轮廓向较慢恢复方向偏移的实验对象中获得了最高电荷值；该组中的电极尖端比脉冲持续时间对不应期恢复无影响的实验对象的电极尖端位于更靠前的位置。似乎在某些位置，当采用合适的刺激参数时，恢复缓慢的元件可对脑刺激奖赏的潜在神经回路产生影响。
