Figure 6.

Ca²⁺ activity in enteric neurons expressing nNOS- GCaMP3 and ChAT- GCaMP3. (A_i) Image of nNOS-GCaMP3 neurons in colonic myenteric ganglia and (A_ii) an activity map of those neurons displaying spontaneous Ca²⁺ transients. A trace of spontaneous Ca²⁺ activity is shown at the bottom of the panel. (B) Image in the left panel shows another myenteric ganglia in which (right panel) the Ca²⁺ activity in selected neurons was plotted in relation to the distortion produced by a spontaneous CMMC (bottom trace). nNOS neurons displayed different responses during the onset of the CMMC: the top two traces show the activation of two formerly silent neurons, while the bottom two traces show the cessation/silencing of two formerly active neurons. These likely represent interneurons and inhibitory motor neurons respectively. (C_i) Low-power image of ChAT-GCaMP3-expressing neurons in multiple colonic myenteric ganglia from which the rightmost ganglia was magnified (C_ii) and an activity map created (C_iii). (D) Image in the left panel shows another ganglia in which the Ca²⁺ activity (right panel) in selected ChAT-GCaMP3 neurons was plotted. These neurons responded with excitatory responses during the initial phase of a CMMC evoked by mucosal stimulation (three strokes; see bottom trace) and likely represent a mixed population of IPANs, interneurons and excitatory motor neurons.