Dorsal unpaired median neurons

DUM(abdomen), unidentified dorsal unpaired median neurons in abdominal ganglion... 

DUM(lantern), dorsal unpaired median neurons innervating the lantern... 

DUM, dorsal unpaired median neuron DUMETi, dorsal unpaired median neuron innervating I ... 

Figure 4. Octopamine content of various tissues associated with the oviducts of Locusta migratoria. Shaded areas of oviducts illustrate the approximate sites which were assayed. Inset upper right depicts a camera lucida drawing of one of the dorsal unpaired median neurons (DUMOV) injected with Lucifer yellow. Scale bar 50 jam. Data from reference 9.

Although these rhythmic contractions of the extensor>tibiae are initiated by spontaneous depolarizations in certain fibers within the muscle, they are regulated by a specific cell on the dorsal surface of the metathoracic ganglion. This cell is found in a cluster of neurosecretory cells called the dorsal unpaired median (DUM) neurons. Neuromuscular transmission and muscular contraction in the extensor-tibiae muscle is modulated by the biogenic amine octopamine and by the peptides, proctolin, and FMRFamide. 

This chapter describes the use of this sensitive technique to measure rigorously biogenic amine levels in individually isolated insect identified neurons, and we present data from the locust protocerebral medulla 4 (PM4) neurons as a specific example (5). We also describe the use of GC-MS to monitor the biosynthesis of biogenic amines. The example we present is the synthesis ofp-octopamine, in populations of the dorsal unpaired median (DUM) neurons of the locust, by following the fate of one of its precursors in deuterated form, [ Hs] p-tyramine (4). 

Voltage clamp experiments using identified neurons, dorsal unpaired median (DUM) neurons from the terminal abdominal ganglion of P. americana, demonstrated that DCJW inhibited the peak Na+ current with an IC50 of 28 nM [38]. DCJW (7) (100 mv[) induced a hyperpolarization of DUM neurons associated with block of background Na channels involved in maintenance of the resting potential. While the peak Na+ current was inhibited, DCJW had no effect on either activation or inactivation kinetics (Fig. 29.4.13). Zhao et al. (2005) similarly... 

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