The expression and function of TRPV4 channels in primate retinal ganglion cells and bipolar cells

Confocal micrographs of retinal slices are double or triple-labeled for TRPV4 (green, LS-C135), GABA (red, a) and TO-PRO-3 (blue). TRPV4 signals appear as puncta, and large and medium RGCs (open arrow, a) in the ganglion cell layer (GCL) negative for GABA are the most intensively labeled. In these RGCs, TRPV4 puncta are larger and denser in the cytosol and absent inside the nucleus. Smaller RGCs in the GCL that are negative for GABA are moderately (arrow, a) to weakly (triangle, a) positive for TRPV4. TRPV4 signals show a higher density in the outer and inner plexiform layers (OPL and IPL, respectively, b) than in the inner and outer nuclear layers (INL and ONL, respectively). In nuclear layers, TRPV4 signals are sparse and often surround cell bodies (b). Scale bars are 20？μ