A topographic gradient of molecules in retina can be used to identify neuron position.

A monoclonal antibody was obtained that binds to cell membrane molecules distributed in a topographic gradient in avian retina. Thirty-five-fold more antigen was detected in dorsoposterior retina that in ventroanterior retina. Most of the antigen was associated with the synaptic layers of the retina. Less antigen was detected in cerebrum, thalamus, cerebellum, and optic tectum, but little or none was found in non-neural tissues tested. The antigen was found on most or all cell types in retina, and the concentration of antigen found is a function of the square of the circumferential distance from the ventroanterior pole of the gradient toward the dorsoposterior pole. Thus, the antigen can be used as a marker of cell position along the ventroanterior-dorsoposterior axis of the retina.