Activity Blockade and GABAA Receptor Blockade Produce Synaptic Scaling through Chloride Accumulation in Embryonic Spinal Motoneurons and Interneurons
Figure 3
Clomeleon measurements confirm high levels of Cl-in in spinal motoneurons.
A) Scatter plot demonstrating the range of FRET ratios measured from motoneurons from 33 chick spinal cords (E10). The average from 330 motoneurons is 1.92±0.01, and is indicated by the red bar. B) Graph indicating the average ratios from the calibration experiments (black dots, n = 5 cords, error bars represent S.E.M.) as well as the relationship between the calibration ratios and Cl−in for somas (grey line, see methods for details). C) When ratios measured from motoneuron somas are converted to Cl−in, we find that the average at E8 is significantly higher than at E9 or E10 (p<0.001). However, values at E9 and E10 are not significantly different (n.s., p = 0.97).