Truini A, Rossi P, Galeotti F, Romaniello A, Virtuoso M, De Lena C, Leandri M, Cruccu G
Department of Neurological Sciences, University "La Sapienza", Viale Università 30, 00185, Rome, Italy.
Exp Brain Res. 2004 Mar;155(1):120-3. doi: 10.1007/s00221-003-1785-x. Epub 2004 Jan 17.
To investigate the excitability of Adelta nociceptive pathways and the nature of the vertex laser evoked potentials (LEPs), we studied the recovery cycle of the P2-LEP component and compared it with that of the P200 of the somatosensory evoked potential (SEP). Using two identical CO(2)-laser stimulators, we delivered paired stimuli to two adjacent skin spots on the hand at interstimulus intervals ranging from 250 ms to 2 s. The test P2-LEP was strongly inhibited at the 250-ms interstimulus interval ( P<0.01) and progressively recovered by the 2-s interval. The P200-SEP, after paired stimuli to the median nerve, showed a time course even slower than the P2-LEP ( P<0.01). Besides providing the LEP recovery curve in normal subjects, our findings indicate that the P2-LEP relays through a number of synapses similar to (or even lower than) that for the P200-SEP, thus lending further support to the view that the nociceptive P2-LEP is not an endogenous potential equivalent to the P300.
为了研究Aδ伤害性感受通路的兴奋性以及头顶激光诱发电位（LEP）的性质，我们研究了P2-LEP成分的恢复周期，并将其与体感诱发电位（SEP）的P200的恢复周期进行比较。我们使用两台相同的CO₂激光刺激器，以250毫秒至2秒的刺激间隔对手上两个相邻的皮肤点进行配对刺激。在250毫秒的刺激间隔时，测试的P2-LEP受到强烈抑制（P<0.01），并在2秒的间隔时逐渐恢复。在对正中神经进行配对刺激后，P200-SEP显示出比P2-LEP更慢的时间进程（P<0.01）。除了提供正常受试者的LEP恢复曲线外，我们的研究结果表明，P2-LEP通过的突触数量与P200-SEP相似（甚至更低），从而进一步支持了伤害性P2-LEP不是等同于P300的内源性电位这一观点。
