Oz Roy, Edelman-Klapper Hadar, Nivinsky-Margalit Shany, Slovin Hamutal
The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel.
Cereb Cortex. 2023 Apr 25;33(9):5192-5209. doi: 10.1093/cercor/bhac409.
Intracortical microstimulation (ICMS) in the primary visual cortex (V1) can generate the visual perception of a small point of light, termed phosphene, and evoke saccades directed to the receptive field of the stimulated neurons. Although ICMS is widely used, a direct measurement of the spatio-temporal patterns of neural activity evoked by ICMS and their relation to the neural responses evoked by visual stimuli or how they relate to ICMS-evoked saccades are still missing. To investigate this, we combined ICMS with voltage-sensitive dye imaging in V1 of behaving monkeys and measured neural activity at a high spatial (meso-scale) and temporal resolution. We then compared the population response evoked by small visual stimuli to those evoked by microstimulation. Both stimulation types evoked population activity that spread over few millimeters in V1 and propagated to extrastriate areas. However, the population responses evoked by ICMS have shown faster dynamics for the activation transients and the horizontal propagation of activity revealed a wave-like propagation. Finally, neural activity in the ICMS condition was higher for trials with evoked saccades as compared with trials without saccades. Our results uncover the spatio-temporal patterns evoked by ICMS and their relation to visual processing and saccade generation.
在初级视觉皮层（V1）进行皮层内微刺激（ICMS）可产生一种小光点的视觉感知，即光幻视，并诱发指向受刺激神经元感受野的扫视运动。尽管ICMS被广泛应用，但对于ICMS诱发的神经活动的时空模式及其与视觉刺激诱发的神经反应的关系，或者它们与ICMS诱发的扫视运动的关系，仍缺乏直接测量。为了研究这一点，我们将ICMS与行为猴子V1区的电压敏感染料成像相结合，并以高空间（中尺度）和时间分辨率测量神经活动。然后，我们将小视觉刺激诱发的群体反应与微刺激诱发的群体反应进行了比较。两种刺激类型都诱发了在V1区扩散几毫米并传播到纹外区域的群体活动。然而，ICMS诱发的群体反应在激活瞬变方面表现出更快的动力学，并且活动的水平传播显示出波状传播。最后，与无扫视运动的试验相比，有诱发扫视运动的试验在ICMS条件下的神经活动更高。我们的结果揭示了ICMS诱发的时空模式及其与视觉处理和扫视运动产生的关系。
