IDENTIFIED NEURONAL CELLS AND SENSORY NEUROPILS IN THE VENTRAL NERVE CORD OF AN INSECT STAINED BY NADPH-DIAPHORASE HISTOCHEMISTRY

The paper describes neurons and neuropilar compartments stained by NAD PH-diaphorase histochemistry in the ventral nerve cord of the cricket, Gryllus bimaculatus, using wholemounts and serial sections. All thora cic and abdominal ganglia contain NADPH-diaphorase-reactive single neu rons or nerve cell clusters, representing interneurons, motorneurons a nd sensory elements. Segmental homonomous neurons are shown. Intense N ADPH-diaphorase reactivity is noted for sensory tracts and for a large sensory neuropile, the whole ventral association centre of all ventra l ganglia. To further determine NADPH-diaphorase-positive neurons and to search for identified neurons, with anatomy, physiology and transmi tter contents described previously, several double marking procedures were successfully applied. Lucifer yellow iontophoresis of single dors al unpaired medial (DUM) cells allows subsequent NADPH-diaphorase stai ning of the cluster of these octopamine containing neurons. Neurobioti n backfilling of nerve cells, visualized by immunofluorescence and fol lowed by NADPH-diaphorase histochemistry, led to the identification of NADPH-diaphorase reactive DUM cells and other efferent neurons. In th e prothoracic ganglion, acoustic and other sensory neuropiles appeared double marked by neurobiotin backfills and NADPH-diaphorase histochem istry. The double marking techniques presented can be routinely used.