Monoclonal antibodies to human neuron-specific enolase reveal heterogeneity of the enzyme in neurons of the central nervous system.

Three monoclonal antibodies to human neuron-specific enolase (NSE) were used to survey the human brain and spinal cord for immunoreactivity. Two of the antibodies (EB and CF) recognized the same population of cells and cell processes. Reactivity was restricted to myelinated axons, basket cell bodies and processes, and a small population of pyramidal cell bodies in the visual cortex. The third antibody (AD) reacted with some, but not all, of the neuronal cell bodies in cerebral cortex, hippocampus, midbrain, and spinal cord. Many neurons did not react with any of the antibodies. The epitope recognized by AD was trypsin-sensitive, while those recognized by EB and CF were not. These studies suggest that NSE may have multiple conformational or structural forms which are segregated between the cell body and axon.