Spatial-temporal stimulus interactions in primate SI hand cortex neurons

灵长类 SI 手皮层神经元的时空刺激相互作用

• 批准号: 7345400
• 负责人: JAMIE L REED
• 金额: $ 2.56万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7345400
• 关键词: Affect; Area; Bilateral; Cercopithecus hamlyni; Chiroptera; Complex; Condition; Contralateral; Denervation; Digit structure; Discrimination; Distant; Esthesia; Evoked Potentials; Face; Fingers; Foundations; Future; Hand; Hand functions; Human; Implant; Injection of therapeutic agent; Injury; Integration Type; Investigation; Ipsilateral; Lateral; Lesion; Lidocaine; Local Anesthetics; Location; Measures; Mediating; Microelectrodes; Monkeys; Nervous System Trauma; Neurologic; Neurons; Night Monkey; Northern Night Monkey; Personal Satisfaction; Phantom Limb; Placement; Primates; Process; Raccoons; Range; Rattus; Recovery; Reporting; Research; Shapes; Site; Somatosensory Cortex; Source; Stimulus; Synaptic plasticity; Syndrome; System; Tactile; Testing; Time; Touch sensation; Upper arm; Vibrissae; Work; base; concept; dorsal column; human study; interest; millisecond; object perception; receptive field; relating to nervous system; research study; response; somatosensory; stroke recovery

DESCRIPTION (provided by applicant): We will chronically implant microelectrode arrays in monkey somatosensory hand cortex to study neuron responses, with the focus on effects of applying two stimuli that vary in spatial and temporal proximity. Results will reveal contextual effects that are relevant to human tactile processing and may relate to the basis of object discrimination. The long-term objective of the study is to determine how and where the somatosensory system mediates object perception and related abilities in order to better characterize the aspects of somatosensory processing that underlie neurological phenomena like phantom limb syndrome or recovery from stroke or other neurological damage to the somatosensory system. The idea guiding the proposal is that object discrimination requires integration of information from across the hand, and this integration is likely to involve primary somatosensory cortex (area 3b). We hypothesize that responses of area 3b neurons will be modulated when two stimuli are nearer in spatial and temporal proximity, but that modulations will occur even when stimuli are separated by substantial distances. We base this hypothesis on 1) several lines of evidence that near stimuli (on adjacent digits or whiskers) applied closely in time modulate the neuron response to the stimulus in the receptive field, 2) interhemispheric interactions that can be unmasked in area 3b, and 3) preliminary studies indicating that such sources of surround modulation are not limited to spatially proximate stimuli. In Aim 1, we will mechanically stimulate paired finger locations to assess how modulation of neural responses may be related to spatial and temporal proximity of the two stimuli. In Aim 2, we will administer local lidocaine injections to block input from one hand and characterize responses to stimulation on the opposite hand, in order to deduce effects of normal levels of spontaneous activity from the opposite hemisphere on shaping 3b neuron activity. Thus, we will examine interactions between responses to stimuli delivered to sites across the hand or hands to investigate how neurons in somatosensory cortex respond to a stimulus in the receptive field, in the context of a distant stimulus. Relevance: The normal functions of neurons in the somatosensory system are relevant not only for understanding the normal sense of touch, but also to understanding recoveries from stroke or damage to the somatosensory cortex (i.e., understanding the extent to which processing is altered by lesions and to what extent normal function returns to the area with or without therapy). Future experiments (dorsal column lesions) are planned to test this further, but the proposed study is part of the foundational work necessary to interpret such future studies.

描述（由申请人提供）：我们将在猴子的体感手皮层长期植入微电极阵列来研究神经元的反应，重点研究施加两种不同空间和时间接近的刺激的效果。结果将揭示与人类触觉处理相关的情境效应，并可能与物体辨别的基础有关。该研究的长期目标是确定体感系统如何以及在何处调节物体感知和相关能力，以便更好地表征体感处理的各个方面，这些方面是幻肢综合征或中风或其他体感系统神经损伤恢复等神经现象的基础。该提议的指导思想是，辨别物体需要整合来自整个手的信息，而这种整合可能涉及初级体感皮层（3b区）。我们假设，当两个刺激在空间和时间上接近时，3b区神经元的反应将被调节，但即使刺激相隔很远，也会发生调节。我们的假设基于以下几个方面：1)近距离刺激（邻近的手指或须）在时间上紧密应用，可以调节神经元对感受野刺激的反应；2)可以在3b区发现的半球间相互作用；3)初步研究表明，这种环绕调制来源并不局限于空间上的近距离刺激。在目标1中，我们将机械刺激成对的手指位置，以评估神经反应的调节如何与两个刺激的空间和时间接近有关。在目的2中，我们将局部注射利多卡因来阻断一只手的输入，并表征另一只手对刺激的反应，以推断来自对侧半球的正常自发活动水平对形成3b神经元活动的影响。因此，我们将研究传递到手或手的不同部位的刺激反应之间的相互作用，以研究在远距离刺激的背景下，体感皮层的神经元如何对感受野中的刺激作出反应。相关性：体感觉系统中神经元的正常功能不仅与理解正常的触觉有关，而且与理解中风或体感觉皮层损伤后的恢复有关（即，理解病变改变处理的程度，以及在接受或不接受治疗的情况下该区域恢复正常功能的程度）。未来的实验（背柱损伤）计划进一步验证这一点，但拟议的研究是解释此类未来研究所需的基础工作的一部分。