Lectin receptors in the cockroach neuromuscular system. III. Distribution and identification within the thoracic ganglia of the nervous system

Abstract

A fluorescence microscopic study of the binding of an array of 10 fluorescein isothiocyanate conjugated lectins to frozen sections of the cockroach thoracic ganglia was performed. Although a region of the neuropile receiving direct input from sensory neurons was observed to have distinctive lectin binding properties, no difference was detected between the lectin binding properties of D f and D s, the two identified motor neurons that innervate the coxal depressor muscles in the leg. In addition, the three types of neurons identified in the ganglia, excitatory motor neurons, inhibitory motor neurons and dorsal unpaired median cells all had identical lectin binding properties. Therefore, in order to demonstrate the existence of macromolecules responsible for giving a biochemical identity to the various neurons it will be necessary to perform biochemical analyses of single cells or apply immunological techniques. A biochemical analysis of the ganglionic Con A and WGA receptors detected after fractionation by SDS polyacrylamide gel electrophoresis revealed the presence of some receptors not found in extracts of muscles and which may be specific for ganglia. In addition, a set of ganglionic lectin receptors were detected which were of similar solubility and lectin binding properties to a set of receptors found in muscle extracts and which disappeared from the muscles within one week of their denervation. It is suggested that such lectin receptors are found in all motor neurons and are transported to axon terminals within the muscles.