Auditory Thalamus and Auditory Cortex Are Equally Modulated by Context during Flexible Categorization of Sounds
Auditory Thalamus and Auditory Cortex Are Equally Modulated by Context during Flexible Categorization of Sounds
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DOI：
10.1523/jneurosci.4888-13.2014
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发表时间：
2014-04-09
影响因子：
5.3
通讯作者：
Zador, Anthony M.
中科院分区：
文献类型：
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作者：
Jaramillo, Santiago;Borges, Katharine;Zador, Anthony M.
在一个动态的世界里，动物必须迅速适应环境线索意义的变化。这种变化会影响感官刺激的神经表征。先前的研究表明，将刺激与奖励或惩罚相关联可以调节听觉皮层（AC）及其丘脑输入（内侧膝状体（MGB））的神经活动。然而，目前还不知道是否刺激行动协会单独的变化也可以调节这些领域的神经反应。我们为大鼠设计了一个分类任务，在这个任务中，将低频和高频声音分开的边界在一个行为会话中多次变化，从而使我们能够操纵与某些声音相关的动作，而不改变相关的奖励。我们开发了一个计算模型，该模型解释了大鼠的表现，并将该模型的预测与执行此任务的动物AC和MGB中单个神经元的声音诱发反应进行了比较。我们发现，15%的AC神经元和16%的MGB神经元的反应调制的刺激-动作关联的变化和调制的幅度是两个大脑区域之间的可比性。我们的研究结果表明，AC和丘脑只发挥有限的作用，在介导的变化之间的关联声刺激和行为反应。
In a dynamic world, animals must adapt rapidly to changes in the meaning of environmental cues. Such changes can influence the neural representation of sensory stimuli. Previous studies have shown that associating a stimulus with a reward or punishment can modulate neural activity in the auditory cortex (AC) and its thalamic input, the medial geniculate body (MGB). However, it is not known whether changes in stimulus-action associations alone can also modulate neural responses in these areas. We designed a categorization task for rats in which the boundary that separated low-from high-frequency sounds varied several times within a behavioral session, thus allowing us to manipulate the action associated with some sounds without changing the associated reward. We developed a computational model that accounted for the rats' performance and compared predictions from this model with sound-evoked responses from single neurons in AC and MGB in animals performing this task. We found that the responses of 15% of AC neurons and 16% of MGB neurons were modulated by changes in stimulus-action association and that the magnitude of the modulation was comparable between the two brain areas. Our results suggest that the AC and thalamus play only a limited role in mediating changes in associations between acoustic stimuli and behavioral responses.