Average neuronal Ca2+ decayed after passivity onset, while average glial Ca2+ increased before passivity onset and peaked soon after. ... This increase in glial Ca2+ started seconds before passivity onset
Figure 2B and 2C (one example fish, 64 events); Figure 2G and 2I; Results, Correlates of Passivity in Neuronal and Astrocytic Activity, paragraph 2
The whole-brain glial signal rises before passivity onset and peaks after it in 2 of 4 two-colour fish (20170228-3 and 20170228-4; 1 to 4 s after onset 0.61 and 0.53 SD above baseline, p = 8.0e-13 and 1.1e-14; 2 to 0 s before, p = 1.7e-11 and 3.6e-17; peaks 3.5 and 2.5 s after onset). In 20161109-2 and 20170203-1 it falls after onset (-0.91 and -0.64 SD, p = 1 for an increase). The criterion needed 3 of 4. 20170228-3 has 67 onsets, close to the 64 events of the paper's example fish (Figure 2B), so it may be that fish. All 26 onsets of 20161109-2 and 42 of the 46 of 20170203-1 fall in code 32, prolonged open loop with the grating moving. The ActivityStates variant gives the same split, and so does keeping the epochs cut by the edges of an open-loop period, which adds 1 or 2 onsets per fish. Over the first five onsets after the start of each open-loop period the glial response is -1.13 and -0.62 SD in 20161109-2 and 20170203-1, and 0.83 and 1.36 SD in the other two. In 20161109-2 and 20170203-1 the glial trace has an SD of 0.0016 and 0.0011 (0.0097 and 0.0072 in the other two) and correlates with the neuronal trace at 0.58 and 0.59 (0.06 and 0.15). In 20170203-1 the neuronal trace also has a low SD (0.0016, against 0.0069 to 0.0180 in the other fish) and rises after onset (+0.28 SD, p = 0.0023), unlike the other three two-colour fish, so there the low SD affects both channels. The data here do not show why these two files differ.
How the test differed from the paper’s method
- Whole-brain average of glia, as in the paper's Figure 2C, not the L-MO component of Figure 2G and 2I, which needs the cross-fish clustering and template registration.
- The glia of these fish carry jRGECO1b; the paper's component analysis used GCaMP6f.