Prefrontal Neurons of Opposite Spatial Preference Display Distinct Target Selection Dynamics
Prefrontal Neurons of Opposite Spatial Preference Display Distinct Target Selection Dynamics
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DOI：
10.1523/jneurosci.5156-12.2013
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发表时间：
2013-05-29
影响因子：
5.3
通讯作者：
Martinez-Trujillo, Julio C.
中科院分区：
文献类型：
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作者：
Lennert, Therese;Martinez-Trujillo, Julio C.
灵长类动物一侧半球背外侧前额皮质（dlPFC）中的神经元对两个视觉半场中关注目标的位置具有选择性。对相反半场具有选择性的 dlPFC 神经元是否直接相互竞争目标选择，或者在注意力分配过程中发挥不同的作用，目前尚不清楚。我们通过记录两只猕猴右侧 dlPFC 的神经元反应来探索这个问题，同时它们将注意力分配到一个半视野的目标并忽略另一侧的干扰物。所记录的神经元中有百分之四十九具有目标位置选择性。选择性对侧目标的神经元 (58%) 比选择性同侧目标的神经元 (42%) 更快地系统地区分目标和干扰物。此外，在感觉刺激保持不变但两种刺激与任务无关并且要求动物检测注视点颜色变化的试验中，对侧神经元仍然能够可靠地区分假定目标和干扰物，而同侧神经元却不能。后一个结果表明对侧神经元的目标-干扰物辨别可能独立于同侧细胞的辨别而发生。因此，这两种细胞类型可能代表前额叶电路的两个不同组成部分，这些部分是在存在干扰物的情况下将注意力分配给目标的基础。此外，对侧半视野中干扰物的存在大大降低了对侧和同侧神经元对单个目标的反应。这一结果表明，干扰物的存在触发了 dlPFC 电路内的抑制性相互作用，从而抑制了对关注目标的反应。
Neurons in the primate dorsolateral prefrontal cortex (dlPFC) of one hemisphere are selective for the location of attended targets in both visual hemifields. Whether dlPFC neurons with selectivity for opposite hemifields directly compete with each other for target selection or instead play distinct roles during the allocation of attention remains unclear. We explored this issue by recording neuronal responses in the right dlPFC of two macaques while they allocated attention to a target in one hemifield and ignored a distracter on the opposite side. Forty-nine percent of the recorded neurons were target location selective. Neurons selective for contralateral targets (58%) systematically discriminated targets from distracters faster than neurons selective for ipsilateral targets (42%). Additionally, during trials in which sensory stimulation remained the same but both stimuli were task irrelevant and animals were required to detect a change in the color of a fixation spot, contralateral neurons still reliably discriminated the putative target from the distracter, whereas ipsilateral neurons did not. The latter result indicates that target-distracter discrimination by contralateral neurons could occur independently of discrimination by ipsilateral cells; thus, the two cell types may represent two different components of the prefrontal circuitry underlying the allocation of attention to targets in the presence of distracters. Moreover, the response of both contralateral and ipsilateral neurons to a single target was substantially reduced by the presence of a distracter in the contralateral hemifield. This result suggests that the presence of the distracter triggered inhibitory interactions within the dlPFC circuitry that suppressed responses to the attended target.