Morphological and physiological characteristics of the serotonin-immunoreactive neuron in the antennal lobe of the male oriental tobacco budworm, Helicoverpa assulta.
We have characterized, by intracellular recording and staining combined with immunocytochemistry, a serotonin-immunoreactive neuron in the central olfactory pathway of the male moth Helicoverpa assulta. The neuron joins the unique category of so-called SI antennal-lobe neurons, previously described in several insect species. In similarity with that originally discovered in the sphinx moth Manduca sexta, the neuron identified here has a large soma located posteriorly in the lateral cell cluster of the antennal lobe and an unbranched neurite projecting into the ipsilateral protocerebrum via the inner antennocerebral tract. After bypassing the central body, the axon crosses the midline and extends through the corresponding antennocerebral tract to the contralateral antennal lobe where it innervates the entire assembly of glomeruli including the male-specific macroglomerular complex. The neuron arborizes into several fine branches in bilateral protocerebral regions anterior to the calyces of the mushroom bodies, particularly on the contralateral side. The physiology of the neuron revealed 2 distinctly different spiking amplitudes, 1 small showing a relatively high spontaneous activity and 1 large showing low activity. The small-amplitude spikes displayed increased frequency when pheromones and plant odors were blown over the antenna. The large-amplitude spikes, which had an unusually long duration, showed no observable responses.
Zhao
Xin Cheng
XC
Department of Psychology/Neuroscience Unit, MTFS, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
Berg
Bente Gunnveig
BG
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism; D008297:Male; D018613:Microscopy, Confocal; D009036:Moths / Q000033:anatomy & histology / Q000166:cytology*; D009474:Neurons / Q000276:immunology / Q000502:physiology* / Q000648:ultrastructure; D009833:Olfactory Pathways; D012701:Serotonin / Q000032:analysis* / Q000276:immunology
D001679:Biogenic Amines; D012701:Serotonin