The range of observed responses is exposed in figure \ref{489066}A. Upon stimulation, effects ranged from a total absence of change (figure \ref{489066}Aiii) to very large reliable transients (figure \ref{489066}Ai). In between those extremes, transients of variable size and reliability could be observed (figure \ref{489066}B). Interestingly, we could also observe inhibitory responses. This was rendered possible by the fact that -- at least in some cell types -- the baseline fluorescence was fluctuating during the experiment (see Discussion and figure SXX) : even if hyperpolarizations below the resting potential are likely not detectable through GCaMP imaging, inhibition from an excited state do appear as dips in the fluorescence trace (figure \ref{489066}Aii).