Fig. 9.
Ca2+ transients in nNOS-GCaMP3 neurons recorded from several myenteric ganglia of the proximal colon during a period of tonic inhibition before or after treatment with the 5-HT receptor antagonist ondansetron and cotreatment with the nicotinic acetylcholine receptor (nAChR) antagonist hexamethonium. Some nitrergic neurons ceased (cells 1, 2, and 8), while others reduced their firing in response to odansetron. Combined treatment with hexamethonium further reduced the amplitudes and frequency of activity within most nNOS-GCaMP3 neurons.