Fig. 1

In vivo calcium imaging from the TG. (a) The distal processes of pseudouniploar neurons of the TG innervate the face, including the oral cavity. Thus, stimulation of the tooth will activate the neurons in the TG. (b). Top, Location of trigeminal ganglion (TG) along with cranial nerve II (CN II), V1, V2, V3 branches and cranial nerve V (CN V). Bottom, the locations of the neurons that receive inputs from the lips were labeled with tdTomato. (c). Surgical approach to the TG. Left, The dorsal view of the surgical/imaging site. Right, Schematic view of our imaging approach. A 3 mm × 3 mm × 8 mm glass cuboid was placed through the brain above the TG. (d) The TG was visible using both our surgical microscope (left) and fluorescence microscope (right). (e) Immunostaining for NeuN (red, top) and GCaMP (green, middle). The overlaid image is shown at the bottom. (f) An example of fluorescence images of the TG. Top, average image during the baseline period before sensory stimulation. Middle, average image during sensory stimulation. Bottom , a ΔF/F₀ image during sensory stimulation of the oral cavity. Increased signals were observed in some cells. (g) High zoom images of the TG shown in panel f. (h) Three-dimensional representation of ΔF/F₀ shown in panel f. (i) Distribution of the diameter of the area exhibiting increased fluorescence. The estimation of the diameter was based on Gaussian fitting.