Functional connectomics analysis of synaptic transmission using optogenetics

其目的是开发一种适用于使用光遗传学对突触传递进行基于切片的分析的方法，该方法可以确定被刺激的纤维的起源。将用于ChR 2表达的腺相关病毒载体转染到大鼠脑桥背侧臂旁外侧核（LPB）中五到八周后，蓝光脉冲强烈触发了中央杏仁核被膜部分神经元中CNQX敏感的EPSC，记录在不同角度（冠状和水平）的急性切片中。这些光诱发的EPSC（leEPSC）被TTX阻断，但通过添加4-AP重新出现，表明单突触神经支配，随后是大而持久的IPSC，表明存在多突触前馈抑制。这种“功能性连接组学”技术在识别长距离连接的突触特性方面具有优势，这在传统的电生理学设置中几乎是不可能的。

The aim was to develop a method applicable to slice-based analysis of synaptic transmission using optogenetics that can determine the origin of fibers being stimulated. Five to eight weeks after transfecting adeno-associated virus vectors for ChR2 expression into the lateral parabrachial nucleus (LPB) in the dorsal pons of rats, blue light pulses robustly triggered CNQX-sensitive EPSCs in the neurons in the capsular part of the central amygdala recorded in acute slices of distinct angles (coronal and horizontal). These light-evoked EPSCs (leEPSCs) were blocked by TTX but re-appeared by addition of 4-AP, suggesting monosynaptic innervation, and was followed by a large and long-lasting IPSC, indicative of the presence of polysynaptic feed-forward inhibition. This "functional connectomics" technique has advantages in identifying the synaptic properties of long-distance connections, which has been otherwise almost impossible in the conventional electrophysiology setups.