CROSS-MODAL INTEGRATION AND PLASTICITY IN SOMATOSENSORY

体感中的跨模态整合和可塑性

• 批准号: 6627682
• 负责人: M ALEX MEREDITH
• 金额: $ 22.26万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6627682
• 关键词: auditory cortex; cats; developmental neurobiology; electrophysiology; histology; neural information processing; neural plasticity; neurotransmitter antagonist; neurotransmitters; sensorimotor system; sensorineural hearing loss; sensory cortex; sensory deprivation; single cell analysis; somesthetic sensory cortex; tissue /cell culture; visual cortex; auditory cortex; cats; developmental neurobiology; electrophysiology; histology; neural information processing; neural plasticity; neurotransmitter antagonist; neurotransmitters; sensorimotor system; sensorineural hearing loss; sensory cortex; sensory deprivation; single cell analysis; somesthetic sensory cortex; tissue /cell culture; visual cortex

To make a comprehensive percept of the environment, the brain must take into account inputs from all of its sensory systems. Therefore, at some level in the nervous system, inputs from different sensory modalities must converge onto individual neurons. At present, there is essentially a single model of multisensory processing at the neuronal level: cells in the superior colliculus that receive excitatory afferents from different sensory modalities. However, it is unlikely that the architecture of the midbrain or the excitatory-excitatory nature of its convergent sensory inputs represent the full range of multisensory possibilities. Numerous reports indicate that multisensory convergence also occurs within the cerebral cortex. Here, newly identified connections that violate modality-specific borders may provide a different model to examine other possible forms of multisensory interactions. Specifically, projections within the Anterior Ectosylvian Sulcal (AES) cortex from auditory FAES to somatosensory AES (SIV) cross modality boundaries, but the expected bimodal neurons are not evident. This apparent contradiction (and preliminary data) leads to the hypothesis that the FAES-SIV connection represents a form of excitatory-inhibitory multisensory convergence. Furthermore, these intermodal connections may provide a ready-made substrate on which cross-modal plasticity can it an occur as a result of abnormal postnatal sensory experience. These possibilities will be tested using neuroanatomical and pharmacophysiological methods both in normal somatosensory (SIV) cortex and in that which has been reorganized by neonatal deafening. Because current search paradigms used to identify multisensory neurons are biased toward neurons which receive convergent excitatory inputs, the proposed experiments are likely to reveal a vastly underestimated source of multisensory processing. The proposed studies will also elucidate the circuitry not only for multisensory convergence, but for AES/"association" cortex as well. Ultimately, this excitatory-inhibitory model of multisensory convergence will contribute to a comprehensive conceptual framework in which the mechanisms of perceptual, developmental, and plastic features of a broad range of multisensory cortical processes may be interpreted.

为了对环境有全面的看法，大脑必须考虑其所有感觉系统的投入。因此，在神经系统中的某个级别上，来自不同感觉方式的输入必须融合到单个神经元上。 目前，基本上有一个在神经元级别的多感官处理的单一模型：上丘的细胞，该细胞从不同的感觉方式中接收兴奋性传入。 但是，中脑的体系结构或其收敛感官输入的兴奋性兴奋性性质不可能代表多种感觉的全部范围。 大量报告表明，多感官收敛也发生在大脑皮层内。在这里，新确定的违反特定方式边界的连接可能会提供不同的模型来检查其他可能的多感觉交互形式。 具体而言，从听觉FAE到体感AES（SIV）跨模态边界的前胚膜沟（AES）皮质内的预测，但预期的双峰神经元并不明显。 这种明显的矛盾（和初步数据）导致了以下假设：FAES-SIV连接代表了一种兴奋性抑制性多感官收敛的形式。 此外，这些模式连接可能会提供现成的基材，因为产后异常，可以在该基材上发生跨模式可塑性。 这些可能性将使用正常体感（SIV）皮质的神经解剖学和药物生理方法进行测试，并且在已通过新生儿震耳欲聋的情况下重新组织了这些可能性。 由于用于识别多感觉神经元的当前搜索范例偏向接收兴奋性输入的神经元，因此所提出的实验可能会揭示出大量低估的多感官处理来源。 拟议的研究还将不仅用于多感官收敛，而且还将阐明AES/“关联”皮层的电路。 最终，这种多感觉收敛的兴奋性抑制模型将有助于一个综合的概念框架，在该框架中，可以解释多种多体性皮质过程的知觉，发育和塑性特征的机制。