Detection of Low Salience Whisker Stimuli Requires Synergy of Tectal and Thalamic Sensory Relays
Detection of Low Salience Whisker Stimuli Requires Synergy of Tectal and Thalamic Sensory Relays
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DOI：
10.1523/jneurosci.5746-09.2010
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发表时间：
2010-02-10
影响因子：
5.3
通讯作者：
Castro-Alamancos, Manuel A.
中科院分区：
文献类型：
--
作者：
Cohen, Jeremy D.;Castro-Alamancos, Manuel A.
感觉刺激的检测取决于其心理物理显著性;显著性越高，检测越容易。但目前尚不清楚感觉中继核团是否在检测低突出胡须刺激的能力上存在差异。我们发现，可逆性病变的躯体感觉丘脑或上级丘阻止检测的低显着性触须条件刺激（WCS）在主动回避任务，而不影响检测的高显着性WCS。因此，丘脑和顶盖感觉中继协同工作，以检测低突出的刺激回避行为，但在检测高度突出的刺激是多余的。我们还记录了高和低的显着性刺激诱发的电生理反应，在上级丘和桶皮层的自由行为的动物在主动探索，清醒的不动，和感官检测的主动回避任务。高强度刺激在皮层和上级丘诱发的场电位反应比低强度刺激诱发的场电位反应更大，对频率的适应性更强。FP反应也更多的抑制和适应较少，在积极探索，并成为进一步抑制在桶皮层在成功检测高或低的突出刺激在主动回避任务。此外，单位录音显示，发射率增加上级丘在积极探索，特别是在成功检测到高或低的突出刺激的主动回避任务。我们的结论是，低显着刺激的检测是通过一个稀疏的神经代码分布通过多个感官继电器。
Detection of a sensory stimulus depends on its psychophysical saliency; the higher the saliency, the easier the detection. But it is not known whether sensory relay nuclei differ in their ability to detect low salient whisker stimuli. We found that reversible lesions of either the somatosensory thalamus or superior colliculus blocked detection of a low salience whisker conditioned stimulus (WCS) in an active avoidance task, without affecting detection of a high salience WCS. Thus, thalamic and tectal sensory relays work synergistically to detect low salient stimuli during avoidance behavior, but are redundant during detection of highly salient stimuli. We also recorded electrophysiological responses evoked by high and low salience stimuli in the superior colliculus and barrel cortex of freely behaving animals during active exploration, awake immobility, and sensory detection in the active avoidance task. Field potential (FP) responses evoked in barrel cortex and superior colliculus by high intensity stimuli are larger and adapt more to frequency than those evoked by low-intensity stimuli. FP responses are also more suppressed and adapt less during active exploration, and become further suppressed in barrel cortex during successful detection of either high or low salient stimuli in the active avoidance task. In addition, unit recordings revealed that firing rate increases in superior colliculus during active exploration and especially during successful detection of either high or low salient stimuli in the active avoidance task. We conclude that detection of low salient stimuli is achieved by a sparse neural code distributed through multiple sensory relays.