Arrays of MicroLEDs and Astrocytes: Biological Amplifiers to Optogenetically Modulate Neuronal Networks Reducing Light Requirement
Arrays of MicroLEDs and Astrocytes: Biological Amplifiers to Optogenetically Modulate Neuronal Networks Reducing Light Requirement
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DOI：
10.1371/journal.pone.0108689
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发表时间：
2014-09-29
期刊：
影响因子：
3.7
通讯作者：
Mannaioni, Guido
中科院分区：
文献类型：
--
作者：
Berlinguer-Palmini, Rolando;Narducci, Roberto;Mannaioni, Guido
在突触传递的现代观点中，星形胶质细胞不再局限于仅仅支持细胞的作用。虽然它们不产生动作电位，但它们仍然表现出电活动，并能通过胶质递质释放影响周围的神经元。在这项工作中，我们探讨了胶质细胞的光遗传激活是否可以作为光神经刺激的放大机制，通过胶质传递到神经网络。我们通过通道视紫红质-2 （ChR2）的选择性光激活和在470 nm处激发峰的可单独寻址的超亮微led （mu LEDs）矩阵研究了脑胶传递的调制。我们结合Ca2+成像技术和并发膜片钳电生理学来获得随后的胶质细胞/神经活动。首先，我们测试了mu led对chr2转染的星形胶质细胞的刺激作用。chr2诱导的星形细胞电流不会随着时间的推移而脱敏，并且随着LED辐照度的增加，电流在强度和表面照度方面呈线性增加和延长。随后，相同光谱轮廓的宽视场LED照明刺激ChR2星形细胞，增加胶质细胞和神经元钙瞬态频率和sEPSCs，这表明很少有ChR2转染的星形细胞能够激发周围未转染ChR2的星形细胞和神经元。最后，通过使用mu led阵列选择性光刺激ChR2阳性星形胶质细胞，我们能够增加其周围单个神经元的突触活性。综上所述，chr2转染的星形胶质细胞和mu LEDs系统在皮质神经元和胶质细胞混合培养中被证明是突触活性的放大器。
In the modern view of synaptic transmission, astrocytes are no longer confined to the role of merely supportive cells. Although they do not generate action potentials, they nonetheless exhibit electrical activity and can influence surrounding neurons through gliotransmitter release. In this work, we explored whether optogenetic activation of glial cells could act as an amplification mechanism to optical neural stimulation via gliotransmission to the neural network. We studied the modulation of gliotransmission by selective photo-activation of channelrhodopsin-2 (ChR2) and by means of a matrix of individually addressable super-bright microLEDs (mu LEDs) with an excitation peak at 470 nm. We combined Ca2+ imaging techniques and concurrent patch-clamp electrophysiology to obtain subsequent glia/neural activity. First, we tested the mu LEDs efficacy in stimulating ChR2-transfected astrocyte. ChR2-induced astrocytic current did not desensitize overtime, and was linearly increased and prolonged by increasing mu LED irradiance in terms of intensity and surface illumination. Subsequently, ChR2 astrocytic stimulation by broad-field LED illumination with the same spectral profile, increased both glial cells and neuronal calcium transient frequency and sEPSCs suggesting that few ChR2-transfected astrocytes were able to excite surrounding not-ChR2-transfected astrocytes and neurons. Finally, by using the mu LEDs array to selectively light stimulate ChR2 positive astrocytes we were able to increase the synaptic activity of single neurons surrounding it. In conclusion, ChR2-transfected astrocytes and mu LEDs system were shown to be an amplifier of synaptic activity in mixed corticalneuronal and glial cells culture.