Antennal lobe projection patterns of olfactory receptor neurons involved in sex pheromone detection in Spodoptera littoralis (Lepidoptera: Noctuidae).
Pheromone-specific receptor neurons in male and female cotton leafworms, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) were typed physiologically and traced into the antennal lobe using cobalt lysine as a marker. In male S. littoralis, the macroglomerular complex (MGC), which is responsible for the initial integration of information concerning sex pheromone components, contains three glomerular compartments as revealed in a morphological study. No such specialized structure was seen in the female. In the male, olfactory receptor neurons that responded selectively to stimulation with the major sex pheromone component, (Z)9, (E)11-tetradecadienyl acetate (Z9E11-14:OAc), had arborizations that were restricted to a large glomerulus of the MGC (designated a), situated near the antennal nerve entrance into the antennal lobe. Neurons that were stimulated by (Z)9,(E)12-tetradecadienyl acetate (Z9E12-14:OAc), a second pheromone component, had arborizations in a lateral, smaller glomerulus of the MGC (designated c), while receptor neurons specifically tuned to a behavioural antagonist, (Z)-9-tetradecenol (Z9-14:OH), projected to a medial glomerulus of the MGC (b). In the female, receptor neurons tuned to the major pheromone component projected to a glomerulus situated at the entrance of the antennal nerve. This glomerulus did, however, not have the size or the structure of the male MGC. A second neuron housed in the same sensillum projected its axon to an ordinary glomerulus situated medially in the antennal lobe.
Ochieng
S A
SA
Department of Ecology, Lund University, Sweden.
Anderson
P
P
Hansson
B S
BS
D000818:Animals; D005260:Female; D008297:Male; D008839:Microelectrodes; D009434:Neural Pathways / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000502:physiology*; D012679:Sense Organs / Q000502:physiology*; D012724:Sex Attractants / Q000032:analysis*; D012727:Sex Characteristics; D018411:Spodoptera / Q000737:chemistry*; D013194:Staining and Labeling
D012724:Sex Attractants