Key Laboratory of Biorheological Science and Technology of Ministry of Education, Chongqing University, Chongqing, China.
Division of Neuronic Engineering, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Stockholm, Sweden.
J Biophotonics. 2019 Jul;12(7):e201800403. doi: 10.1002/jbio.201800403. Epub 2019 Apr 1.
The aim of the present study is to optimize parameters for inhibiting neuronal activity safely and investigating thermal inhibition of rat cortex neural networks in vitro by continuous infrared (IR) laser. Rat cortex neurons were cultured on multi-electrode arrays until neural networks were formed with spontaneous neural activity. Neurons were then irradiated to inhibit the activity of the networks using different powers of 1550 nm IR laser light. A finite element heating model, calibrated by the open glass pipette method, was used to calculate temperature increases at different laser irradiation intensities. A damage signal ratio (DSR) was evaluated to avoid excessive heating that may damage cells. The DSR predicted that cortex neurons should be safe at temperatures up to 49.6°C for 30 seconds, but experiments suggested that cortex neurons should not be exposed to temperatures over 46°C for 30 seconds. Neural response experiments showed that the inhibition of neural activity is temperature dependent. The normal neural activity could be inhibited safely with an inhibition degree up to 80% and induced epileptiform activity could be suppressed. These results show that continuous IR laser radiations provide a possible way to safely inhibit the neural network activity.
本研究旨在优化安全抑制神经元活性的参数，并通过连续红外（IR）激光研究体外大鼠皮质神经网络的热抑制作用。将大鼠皮质神经元培养在多电极阵列上，直到形成具有自发神经活动的神经网络。然后，使用不同功率的 1550nm IR 激光照射神经元，以抑制网络的活性。使用通过开放玻璃吸管方法校准的有限元加热模型来计算不同激光辐照强度下的温升。评估损伤信号比（DSR）以避免可能损害细胞的过度加热。DSR 预测，在 30 秒内，温度高达 49.6°C 时皮质神经元应该是安全的，但实验表明，皮质神经元在 30 秒内不应暴露于超过 46°C 的温度。神经反应实验表明，神经活动的抑制与温度有关。正常的神经活动可以安全地抑制，抑制程度高达 80%，并可以抑制诱导的癫痫样活动。这些结果表明，连续的 IR 激光辐射为安全抑制神经网络活动提供了一种可能的方法。
