Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY 14642, USA.
Neuron. 2009 Dec 10;64(5):730-43. doi: 10.1016/j.neuron.2009.11.018.
Discrimination tasks require processing, interpreting, and linking sensory information to the appropriate motor response. We report that neurons in prefrontal cortex (PFC) represent visual motion with precision comparable to cortical neurons at early stages of motion processing, and readily adapt this representation to behavioral context. We found that direction selectivity, recorded while the monkeys discriminated directions, decreased when they judged motion speed and ignored its direction. This decrease was more pronounced in neurons classified as narrow-spiking (NS) putative interneurons than in broad-spiking (BS) putative pyramidal neurons. However, during passive fixation, when the link between motion and its behavioral relevance was removed, both cell types showed a severe selectivity loss. Our results show that flexible sensory representation during active discrimination tasks is achieved in the PFC by a specialized neuronal network of both NS neurons readily adjusting their selectivity to behavioral context, and BS neurons capable of maintaining relatively stable sensory representation.
辨别任务需要处理、解释和将感觉信息与适当的运动反应联系起来。我们报告说,前额皮质(PFC)中的神经元以与运动处理早期阶段的皮质神经元相当的精度来表示视觉运动,并且可以轻松地将这种表示适应行为背景。我们发现,当猴子判断运动速度并忽略其方向时,记录到的辨别方向的神经元的方向选择性降低。在被归类为窄峰(NS)拟神经元的神经元中,这种降低比在宽峰(BS)拟锥体神经元中更为明显。然而,在被动注视时,当运动与其行为相关性之间的联系被消除时,两种细胞类型均表现出严重的选择性丧失。我们的结果表明,在主动辨别任务期间,PFC 中灵活的感觉表示是通过 NS 神经元的专门神经网络实现的,这些神经元可以轻松地根据行为背景调整其选择性,而 BS 神经元能够维持相对稳定的感觉表示。