Stimulus-Specific SI Corticocortical Interactions

描述（由申请人提供）：将研究以下操作：（1）改变脊髓背角中感觉输入的处理，以及（2）伴随动物和人类的躯体感觉感知的明显异常。目标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与皮肤热刺激的差异反应的影响。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（在每次操作之前和之后）神经元群体和单个神经元分析水平上对皮肤热刺激和机械刺激的SI响应。该项目预计将（1）揭示由自然皮肤刺激诱发的SI皮层反应对修改脊髓背角神经元的感觉输入处理的操纵的迄今未被认识的敏感性;以及（2）确定对天然皮肤刺激的改变的SI反应可以通过选择性消融NK-1而减弱/逆转的程度（物质P）受体表达神经元的脊髓背角浅层，或通过选择性阻断脊髓NMDA受体。

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.