Fig 4.

Evidence of neuronal–glial gap junctions in trigeminal ganglion in response to capsaicin stimulation. Nerve cell bodies within the V3 region of the ganglion retrogradely labeled with True Blue were obtained from untreated animals (A) or animals injected in the TMJ capsule with capsaicin for 15 (B), 30 (C), 60 (D), or 120 (E) minutes prior to harvesting the ganglia. The corresponding boxed regions on the sections are shown at higher magnification in the right panels (a–e). While True Blue was detected primarily in the cytosol of neuronal cell bodies (thick arrows) of ganglion from control animals (A and a), more dye was detected in the adjacent glial satellite cells (thin arrows) with increasing time following capsaicin injection. At 2 hours, most of the dye is found in the cytosol of adjacent satellite cells (E and e).