and 1.7-fold faster decay time than GCaMP5G (Fig. 1f, g) (Supplementary Table 1). GCaMP6f is the fastest genetically-encoded calcium indicator for cytoplasmic free calcium in neurons, with sensitivity comparable to OGB1-AM (Fig. 1d-g). GCaMP6 indicators were more sensitive and/or faster than other GCaMP variants in presynaptic boutons of the Drosophila larval neuromuscular junction24 (Supplementary Fig. 3; Supplementary Table 4), in projection neurons of the Drosophila adult antennal lobe during odor presentation16 (Supplementary Fig. 4), and in neuropil and somata of the zebrafish tectum in vivo16 (Supplementary Fig. 5).
