Immunohistochemical and biochemical analysis of N-cadherin expression during CNS development.

The expression of the calcium-dependent adhesion molecule N-cadherin during chick embryo central nervous system (CNS) development was examined by immunohistochemistry and electrophoresis and immunoblotting. During histogenesis, N-cadherin is expressed at high levels in a uniform fashion in many regions of the CNS. However, during later stages of development, expression becomes restricted to the ependymal cells lining the ventricular system and in the choroid plexus. This down-regulation was confirmed by both immunohistochemical and biochemical techniques. The program of expression lags behind in the cerebellum in concert with the delayed development of this region of the brain. A high level of N-cadherin was found to be expressed in the brainstem and spinal cord floorplate, while a low level was detected at the optic nerve head. The results indicate that while, in general, the program of N-cadherin expression is similar in the retina and the brain, certain structures unique to the eye and brain express locally high or low levels of this adhesion protein.