Stimulus-Specific SI Corticocortical Interactions

描述（由申请人提供）：操作将被研究：(1)改变脊髓背角的感觉输入处理，(2)在动物和人类中伴有明显的体感知觉异常。目的是检测和定量表征每种操作对正常对侧SI皮层对精确控制的机械和热刺激的不同反应的影响。被麻醉的松鼠猴将作为实验对象。近红外光学固有信号（OIS）成像和细胞外微电极记录尖峰放电活动的方法将用于表征（每次操作前后）在神经元群和单个神经元水平上对皮肤的热刺激和机械刺激的SI反应。该项目预计将(1)揭示迄今为止未被认识到的由自然皮肤刺激引起的SI皮质反应的敏感性，以改变脊髓背角神经元对感觉输入的处理；(2)通过选择性消融脊髓浅表背角中表达NK-1 （P物质）受体的神经元，或通过选择性阻断脊髓NMDA受体，确定对自然皮肤刺激改变的SI反应可以减弱/逆转的程度。

DESCRIPTION (provided by applicant): Manipulations will be studied that (1) modify the processing of sensory input in the spinal cord dorsal horn, and (2) are accompanied by pronounced abnormalities of somatosensory perception in animals and humans. The goals are to detect and quantitatively characterize the effects of each manipulation on the differential responses of normal contralateral SI cortex to precisely controlled mechanical vs. thermal stimulation of the skin. Anesthetized squirrel monkeys will serve as subjects. The methods of near-infrared optical intrinsic signal (OIS) imaging and extracellular microelectrode recording of spike discharge activity will be used to characterize (both before and after each manipulation) the SI responses to thermal and mechanical stimulation of the skin at both the neuron population and single neuron levels of analysis. The project is expected to (1) reveal a hitherto unappreciated sensitivity of the SI cortical response evoked by natural skin stimuli to manipulations that modify the processing of sensory input by spinal cord dorsal horn neurons; and (2) establish the extent to which the altered SI response to natural skin stimuli can be attenuated/reversed by selective ablation of NK-1 (Substance P) receptor expressing neurons in the superficial dorsal horn of the spinal cord, or by the selective block of spinal cord NMDA receptors.