“…The relative simplicity of the arthropod CNS has made possible the unambiguous identification of peptidergic cells and cell groups (Bullock, 1984;Rowell, 1976), and direct analysis of the contents of individual neurosecretory somata has revealed the cellular localization of peptides that modulate steroid secretion (Agui et al, 1979), diuresis (Berlind and Maddrell, 1979), skeletal muscle contraction (O'Shea and , heartbeat acceleration (O'Shea and Adams, 198 1; Tublitz and Truman, 1985), and stage-specific cuticular tanning (Taghert and Truman, 1982). The electrophysiological properties of individual neurosecretory cells have also been determined in several different preparations (Bruce and Wilkens, 1976;Carrow et al, 1984;Miyazaki, 1980;Zaretsky and Loher, 1983), although attempts to monitor the spontaneous activity of peptidergic neurons in a physiologically relevant context have proven less successful.…”