A highly sensitive fluorescent indicator dye for calcium imaging of neural activity in vitro and in vivo.
Bottom Line: Therefore, it is difficult to detect signals caused by single action potentials (APs) particularly from neurons in vivo.Here we showed that a recently developed calcium indicator dye, Cal-520, is sufficiently sensitive to reliably detect single APs both in vitro and in vivo.These characteristics of Cal-520 are a great advantage over those of Oregon Green BAPTA-1, the most commonly used calcium indicator dye, for monitoring the activity of individual neurons both in vitro and in vivo.
Affiliation: Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.Show MeSH
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Mentions: The time course of the change in fluorescence signals by Cal-520 was examined. The mean baseline fluorescence, amplitude, and frequency of spontaneous calcium transients in neurons were compared at different time points during imaging (Fig.6). During 1–4 h after the injection, Cal-520 showed no significant change in the mean amplitude of calcium transients (0.325 ± 0.003 and 0.291 ± 0.009 ΔF/F, P= 0.49, t-test) (Fig.6C), despite an increase of baseline fluorescence intensity (52.8 ± 0.3 and 73.9 ± 0.8 F in 59 cells and 22 cells, respectively, P=0.00002, t-test) (Fig.6B). The frequency of spontaneous calcium transients was also unchanged (0.0457 ± 0.0006 and 0.0391 ± 0.011 Hz, P=0.36, t-test) (Fig.6D).
Affiliation: Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.