The presence and retinal distributions of short-wavelength-sensitive c
ones, long-wavelength-sensitive cones, and rods were assessed in the r
etina of the tree shrew Tupaia belangeri using visual pigment antibodi
es OS-2, COS-1 and anti-rhodopsin, respectively. Results demonstrated
a clear immunocytochemical differentiation of the three photoreceptor
types with each showing regional variation in density across the retin
a.