Fig. 4
From: Sleep increases chromosome dynamics to enable reduction of accumulating DNA damage in single neurons
Neuronal excitation reduces chromosome dynamics in the Rh and SC. a–c Simultaneous 2D imaging of neuronal activity (magenta) and chromosome dynamics (green) in the Rh neurons. d Raster plot of ΔF/F of 27 and 26 RCaMP1b-expressing single cells during day and night, respectively. Grayscale: ΔF/F amplitude. e A moderate negative correlation between chromosome dynamics and neuronal activity during day and night (RDay = −0.62, RNight = −0.64, RTotal = −0.64), determined by Pearson correlation coefficient. The average single-cell activity (f, *Pactivity = 0.035) and chromosome dynamics (g, *Pdynamics = 0.03) during day and night. Determined by two-tailed t-test: two samples assuming unequal variance. h–l Optogenetic stimulation of neuronal activity reduces chromosome dynamics. h–j The neurons expressed both dsRED-TRF1 and ChR2-YFP (arrow) or only dsRED-TRF1 (arrowhead). k, l Chromosome dynamics before and following the light stimuli (ChR2−, n = 9 cells; ChR2+, n = 10 cells). *P = 0.031, determined by two-tailed t-test: two-paired samples for means. Average change is marked by red line. m–o Inhibition of neuronal activity during the night does not affect chromosome dynamics. m Representative raster plots of ΔF/F in the Rh of 6 dpf tg(HuC:GCaMP5) larvae under DMSO (n = 6 larvae) or BAPTA-AM (n = 6 larvae) treatments. Grayscale: ΔF/F amplitude. Bottom: histogram of the Ca2+ transients of all cells. n Average spontaneous neuronal activity in single neurons of the Rh under either DMSO (n = 6 larvae) or BAPTA-AM (n = 6 larvae) treatment (ZT23). *P = 2 × 10−4, t = 2.3, degrees of freedom = 7, determined by two-tailed t-test: two samples assuming unequal variance. o Volume of chromosome dynamics during nighttime (ZT23) in DMSO (n = 13 cells) and BAPTA-AM (n = 11 cells)-treated larvae. Values are presented as boxplots and means (black diamonds) or as dot plots and means ± SEM. Boxplots indicate the median and the 25th-to-75th percentiles. The whiskers extend to the most extreme data points. ZT zeitgeber time. Scale bar = 2 µm
