Ernst Strüngmann Institute for Neuroscience in cooperation with Max Planck Society, 60528 Frankfurt, Germany, University of California San Diego, La Jolla, California 92093-0634, Vanderbilt University, Department of Psychology, Nashville, Tennessee 37240, Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, Maryland 20892, and Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, Bethesda, Maryland 20892.
J Neurosci. 2013 Nov 27;33(48):18740-5. doi: 10.1523/JNEUROSCI.3923-13.2013.
Neurons in cortical ventral-stream area V4 are thought to contribute to important aspects of visual processing by integrating information from primary visual cortex (V1). However, how V4 neurons respond to visual stimulation after V1 injury remains unclear: While electrophysiological investigation of V4 neurons during reversible V1 inactivation suggests that virtually all responses are eliminated (Girard et al., 1991), fMRI in humans and monkeys with permanent lesions shows reliable V1-independent activity (Baseler et al., 1999; Goebel et al., 2001; Schmid et al., 2010). To resolve this apparent discrepancy, we longitudinally assessed neuronal functions of macaque area V4 using chronically implanted electrode arrays before and after creating a permanent aspiration lesion in V1. During the month after lesioning, we observed weak yet significant spiking activity in response to stimuli presented to the lesion-affected part of the visual field. These V1-independent responses showed sensitivity for motion and likely reflect the effect of V1-bypassing geniculate input into extrastriate areas.
皮质腹侧流区 V4 的神经元被认为通过整合来自初级视觉皮层（V1）的信息来促进视觉处理的重要方面。然而，V1 损伤后 V4 神经元对视觉刺激的反应尚不清楚：虽然在可逆 V1 失活期间对 V4 神经元的电生理研究表明几乎所有反应都被消除（Girard 等人，1991），但在具有永久性损伤的人类和猴子的 fMRI 中显示出可靠的 V1 独立活动（Baseler 等人，1999；Goebel 等人，2001；Schmid 等人，2010）。为了解决这一明显的差异，我们使用在 V1 中创建永久性抽吸损伤之前和之后长期植入的电极阵列来纵向评估猕猴 V4 区的神经元功能。在损伤后的一个月内，我们观察到在向视觉场受影响部分呈现刺激时，出现了微弱但明显的尖峰活动。这些 V1 独立的反应对运动敏感，可能反映了绕过 V1 的外侧膝状体输入到外侧区域的影响。
