Calcium imaging in SMA and M1 of macaques

The study of motor cortices in non-human primates is relevant to our understanding of human motor control, both in healthy conditions and in movement disorders. Calcium imaging and miniature microscopes allow the study of multiple genetically identified neurons with excellent spatial resolution. We used this method to examine activity patterns of projection neurons in deep layers of the supplementary motor (SMA) and primary motor areas (M1) in four rhesus macaques. We implanted gradient index lenses and expressed GCaMP6f to image calcium transients while the animals were at rest or engaged in an arm reaching task. We tracked the activity of SMA and M1 neurons across conditions, examined cell pairs for synchronous activity, and assessed whether SMA and M1 neuronal activation followed specific sequential activation patterns. We demonstrate the value of in vivo calcium imaging for studying patterns of activity in groups of corticofugal neurons in SMA and M1.

非人灵长类运动皮层的研究对于理解人类健康状态及运动障碍中的运动控制具有重要意义。钙成像技术与微型显微镜的结合，能够以出色的空间分辨率研究多个基因标记的神经元。我们采用该方法，对四只恒河猴辅助运动区（SMA）和初级运动区（M1）深层的投射神经元活动模式进行了研究。我们植入梯度折射率透镜并表达GCaMP6f，以在动物静息或执行手臂伸展任务时成像钙瞬变。我们追踪了不同状态下SMA和M1神经元的活动，检测了细胞对的同步活动，并评估了SMA和M1神经元激活是否遵循特定的序列激活模式。我们证实了在体钙成像技术对于研究SMA和M1中皮质传出神经元群体活动模式的价值。