Two corticotectal areas facilitate multisensory orientation behavior
Two corticotectal areas facilitate multisensory orientation behavior
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DOI：
10.1162/089892902760807230
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发表时间：
2002-11-15
影响因子：
3.2
通讯作者：
Stein, BE
中科院分区：
文献类型：
--
作者：
Jiang, W;Jiang, H;Stein, BE
先前的研究表明，来自两个皮质区域的影响，即前外侧隐上沟（AES）和吻侧外侧隐上沟（rLS），在使上丘（SC）神经元能够合成其跨模态输入方面起着关键作用。目前的研究考察了选择性地消除这些皮层影响对sc介导的定向反应对跨模态刺激的影响，训练猫在存在或不存在来自另一模态（听觉）的中性提示的情况下，定向到低强度的特定模态线索（视觉）。视觉目标可以出现在中线45度范围内的不同位置，刺激效果变化，平均正确定向反应约为45%。当听觉提示与目标刺激同时存在时，被试的反应增强和抑制表现为：当跨模态刺激在空间上一致时，被试正确反应的概率显著增强，而当跨模态刺激在空间上不同时，被试的反应概率显著降低。低温阻断AES或rLS都会破坏这些行为效应，从而消除了对空间一致的跨模态信号的增强反应，降低了对空间不同的跨模态信号的抑制反应。这些对失活皮层对侧目标的破坏性影响仅限于多感觉交互过程。对特定模式目标的定位没有改变。此外，定向错误的模式不受皮层失活的影响。这些数据与AFS和rLS失活在单个SC神经元水平上对多感觉整合的影响惊人地相似。据推测，消除来自AES或rLS皮层的关键影响会破坏SC多感觉合成，进而禁用SC介导的多感觉定向行为。
It had previously been shown that influences from two cortical areas, the anterior ectosylvian sulcus (AES) and the rostral lateral suprasylvian sulcus (rLS), play critical roles in rendering superior colliculus (SC) neurons capable of synthesizing their cross-modal inputs. The present studies examined the consequences of selectively eliminating these cortical influences on SC-mediated orientation responses to cross-modal stimuli, Cats were trained to orient to a low-intensity modality-specific cue (visual) in the presence or absence of a neutral cue from another modality (auditory). The visual target could appear at various locations within 45degrees of the midline, and the stimulus effectiveness was varied to yield an average of correct orientation responses of approximately 45%. Response enhancement and depression were observed when the auditory cue was coupled with the target stimulus: A substantially enhanced probability in correct responses was evident when the cross-modal stimuli were spatially coincident, and a substantially decreased response probability was obtained when the stimuli were spatially disparate. Cryogenic blockade of either AES or rLS disrupted these behavioral effects, thereby eliminating the enhanced performance in response to spatially coincident cross-modal cues and degrading the depressed performance in response to spatially disparate cross-modal cues. These disruptive effects on targets contralateral to the deactivated cortex were restricted to multisensory interactive processes. Orientation to modality-specific targets was unchanged. Furthermore, the pattern of orientation errors was unaffected by cortical deactivation. These data hear striking similarities to the effects of AFS and rLS deactivation on multisensory integration at the level of individual SC neurons. Presumably, eliminating the critical influences from AES or rLS cortex disrupts SC multisensory synthesis that, in turn, disables SC-mediated multisensory orientation behaviors.