RESUMO
The ultra-histochemistry is a new technique that can give an idea about the anatomical and functional differentiation between cells within a tissue. The study is designed to demonstrate the activity of B- esterase in the alpha motor-neurons of the spinal cord of rabbit. Alpha naphthyl butyrate is used as a substrate for demonstration of the activity of B- esterase in the alpha motor-neurons of the spinal cord of rabbit, using light and electron microscopy for visualization. A higher activity of B-esterase was evident in alpha - II cells in comparison to the alpha - I cells by light microscopy. The details of functional significance and Ultra-structural localization of the enzymes within these cells were visualized by electron microscopy. The nuclear envelope and to a lesser extent the cytoplasm showed B-esterase activity. It is suggested that B-esterase has chemotrypsin like action and play a role in the metabolism of certain neurotransmitters