Saab C Y, Willis W D
Department of Anatomy and Neurosciences, University of Texas Medical Branch, MBI, 301 University Blvd., Galveston, TX 77555-1069, USA.
Exp Brain Res. 2002 Sep;146(1):117-21. doi: 10.1007/s00221-002-1107-8. Epub 2002 Jul 24.
The cerebellum modulates different nociceptive phenomena and influences visceral functions. This study shows cerebellar modulation of an abdominal reflex elicited by a visceral noxious stimulus (colorectal distension, CRD). The intensity of the reflex was measured by electromyographic (EMG) recording from the rectus abdominus muscle, and the cerebellar cortex (vermis, lobule VIII), the fastigial nucleus, or the dentate nucleus was stimulated using D, L-homocysteic acid (0.1 M, 1 micro l). To release the fastigial nucleus from inhibition by the Purkinje cells, bicuculline (GABA(A) receptor antagonist, 100 micro M, 1 micro l) was used. Stimulation of the cerebellar cortex enhanced, whereas stimulation or disinhibition of the fastigial nucleus decreased, the responses to CRD measured by EMG. Stimulation of the dentate nucleus did not have an obvious effect on the intensity of the reflex. These results are in agreement with the hypothesis that the cerebellum modulates visceral nociceptive functions, whereby the cerebellar cortex and the fastigial nucleus, respectively, play a pro-nociceptive and an anti-nociceptive role.
小脑调节不同的伤害性感受现象并影响内脏功能。本研究显示了小脑对由内脏伤害性刺激（结肠扩张，CRD）引发的腹部反射的调节作用。通过记录腹直肌的肌电图（EMG）来测量反射强度，并使用D，L-高半胱氨酸（0.1 M，1微升）刺激小脑皮质（蚓部，小叶VIII）、顶核或齿状核。为了消除浦肯野细胞对顶核的抑制作用，使用了荷包牡丹碱（GABA(A)受体拮抗剂，100微摩尔，1微升）。刺激小脑皮质可增强由EMG测量的对CRD的反应，而刺激或解除对顶核的抑制则会降低该反应。刺激齿状核对反射强度没有明显影响。这些结果与小脑调节内脏伤害性感受功能的假说一致，即小脑皮质和顶核分别发挥促伤害性感受和抗伤害性感受的作用。
