Bantli H, Bloedel J R
Exp Brain Res. 1976 May 28;25(2):199-200. doi: 10.1007/BF00234903.
Experiments were performed to determine the action of the dentate output on neurons in the spinal cord mediated by pathways which do not involve the primary sensorimotor and premotor cortices. The dentate nucleus was electrically stimulated by stereotaxically placed electrodes in Rhesus monkeys whose contralateral sensorimotor and premotor cortices were ablated. The resultant changes in excitability of lumbar alpha motorneurons activated by Ia afferents from nerves innervating femoral, hamstring, gastrocnemius-soleus and peroneal muscles were measured by intracellular recordings and by determining the percent change in the amplitude of the monosynaptic reflex recorded from ventral roots. The effect of stimulation of the dentate nucleus on proprioceptive reflexes was determined by recording the changes in postsynaptic potentials evoked by selective stimulation of Ia and Ib afferent fibers. The results demonstrated that dentate nucleus exerts a significant action on the excitability of spinal neurons via pathways which do not include the sensorimotor and premotor cortices. Whether the dentate stimulus produced an increase or decrease in the excitability of these neurons was dependent upon the site within the dentate nucleus at which the stimulus was applied, demonstrating that, in the decorticate preparation, the output from this nucleus is quite heterogeneous. In addition, stimulation of the dentate nucleus in these monkeys did not affect the Ia reflex pathway but significantly changed the amplitude of the inhibitory postsynaptic potential evoked by Ib afferents in lumbar alpha motorneurons.
进行了实验，以确定齿状核输出对脊髓神经元的作用，该作用由不涉及初级感觉运动皮层和运动前区皮层的通路介导。在恒河猴中，通过立体定位放置的电极对齿状核进行电刺激，这些恒河猴的对侧感觉运动皮层和运动前区皮层已被切除。通过细胞内记录以及测定从腹根记录的单突触反射幅度的变化百分比，来测量由支配股四头肌、绳肌、腓肠肌-比目鱼肌和腓骨肌的神经的Ia传入纤维激活的腰段α运动神经元兴奋性的变化。通过记录选择性刺激Ia和Ib传入纤维诱发的突触后电位变化，来确定齿状核刺激对本体感觉反射的影响。结果表明，齿状核通过不包括感觉运动皮层和运动前区皮层的通路，对脊髓神经元的兴奋性发挥显著作用。齿状核刺激使这些神经元的兴奋性增加还是降低，取决于刺激施加在齿状核内的部位，这表明，在去皮质的标本中，该核的输出相当不均匀。此外，对这些猴子的齿状核进行刺激，并不影响Ia反射通路，但显著改变了腰段α运动神经元中由Ib传入纤维诱发的抑制性突触后电位的幅度。
