Stimulus-Specific SI Corticocortical Interactions

描述(申请人提供)：将研究以下操作：(1)改变脊髓背角感觉输入的处理，以及(2)伴随动物和人类明显的躯体感觉异常。我们的目标是检测和量化每一种手法对正常对侧SI皮质对精确控制的皮肤机械刺激和热刺激的差异反应的影响。麻醉的松鼠猴子将作为受试者。近红外光学本征信号(OIS)成像和细胞外微电极记录棘波放电活动的方法将被用来在神经元群体和单个神经元水平上表征(每次操作前后)SI对皮肤热刺激和机械刺激的反应。该项目有望(1)揭示由自然皮肤刺激引起的SI皮质反应对改变脊髓背角神经元感觉输入的处理过程的迄今未知的敏感性；(2)确定选择性地消融脊髓浅背角表达NK-1(P物质)受体的神经元，或选择性阻断脊髓NMDA受体，可以在多大程度上减弱/逆转自然皮肤刺激引起的SI反应的改变。

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.