TY - JOUR T1 - Optical inhibition of zebrafish behavior with anion channelrhodopsins JF - bioRxiv DO - 10.1101/158899 SP - 158899 AU - Gadisti Aisha Mohamed AU - Ruey-Kuang Cheng AU - Joses Ho AU - Seetha Krishnan AU - Farhan Mohammad AU - Adam Claridge-Chang AU - Suresh Jesuthasan Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/07/03/158899.abstract N2 - In behavioral analysis, optical electrical silencing provides a way to test neuronal necessity. Two light-gated anion channels, GtACR1 and GtACR2, have recently been shown—in neuronal culture and in Drosophila—to inhibit neurons potently. Here, we test the usefulness of these channels in zebrafish. When the GtACRs were expressed in motor neurons and actuated with blue or green light, fish spontaneous movement was inhibited. In GtACR1-expressing fish, only 3 µW/mm2 of light was sufficient to have an effect; GtACR2, which is poorly trafficked, required stronger illumination. After light offset, GtACR-expressing fish movement increased; this suggested that termination of light-induced neural inhibition may lead to depolarization. Consistent with this, two-photon imaging of spinal neurons showed that intracellular calcium also increased following light offset. The activity elicited at light offset needs to be taken into consideration in experimental design, although this property may help provide insight into the effects of stimulating a circuit transiently. These results show that GtACR1 and GtACR2 can be used to optically inhibit neurons in zebrafish, and thus to test neural circuit necessity. ER -