Cayce Jonathan Matthew, Bouchard Matthew B, Chernov Mykyta M, Chen Brenda R, Grosberg Lauren E, Jansen E Duco, Hillman Elizabeth M C, Mahadevan-Jansen Anita
Department of Biomedical Engineering, Vanderbilt University, Station B, Box 351631, Nashville TN 37235, United States.
Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Columbia University, 120th Street and Amsterdam Avenue, New York, NY 10027, United States.
Cell Calcium. 2014 Apr;55(4):183-90. doi: 10.1016/j.ceca.2014.01.004. Epub 2014 Jan 31.
Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain.
红外神经刺激（INS）是一种很有前景的神经刺激技术，它能够以高空间精度激活神经组织，且无需外源性试剂。然而，关于红外光在细胞水平上如何与神经组织相互作用，尤其是在活体大脑中，人们了解甚少。在本研究中，我们在宏观和微观尺度上使用钙敏感染料成像来探究INS对皮质钙动力学的时空效应。观察到的INS诱发的钙信号呈现出快速和慢速成分，表明多种细胞机制被激活。诱发信号的慢速成分呈现出波状特性，表明网络被激活，并且通过药理学和双光子成像证实其起源于星形胶质细胞。我们还提供证据表明，快速钙信号可能是通过谷氨酸瞬变的调制诱发的。这项研究表明，脉冲红外光可在星形胶质细胞和神经元中诱导细胞内钙调制，为INS在大脑中的作用机制提供了新的见解。
