Figure 7. Correcting z‐motion artefacts when measuring synaptic activity in vivo .

A, two‐photon (2‐P) recording in awake behaving mice, as in Fig. 2A . B, two‐photon images (average of 50 frames) with synapses labelled with SyGCaMP6f recorded in parallel with blood vessels labelled with dextran‐TexasRED. C, running speed (top, black trace) is associated with axial displacement of the focal plane (bottom, red trace). D, green and red traces are uncorrected activity traces acquired from two example synapses. The corrected traces are shown in grey and these no longer exhibit changes in fluorescence associated with locomotor bouts. Blue bars show two periods of application of a full‐field grating stimulus (0.04 cycles per degree, 2 Hz, 100% contrast).