Consistent organization of glomeruli in the antennal lobes of related species of heliothine moths

Abstract

The glomeruli of the antennal lobes in insects reflect the organization of the olfactory system, which is important for species-specific behaviors in response to insect- and plant-produced odorants. We studied the antennal lobes of the polyphagous moth Helicoverpa armigera and the oligophagous H. assulta (Heliothinae; Lepidoptera; Noctuidae) in order to see whether there are any anatomical differences that might elucidate how information about odorants is analyzed. Three-dimensional models of the antennal lobes were made, based on synaptic antibody staining combined with confocal laser scanning microscopy. These showed 65 glomeruli in each sex of H. armigera and 66 glomeruli in females of H. assulta. Sixty-two of the glomeruli were identified in both sexes and species and were given the same numbers. The sex-specific glomeruli included three macroglomerular units in H. armigera males, as well as three and four female-specific glomeruli in H. armigera and H. assulta, respectively. The species specificity of H. assulta females also appeared by the particular large size of two ordinary glomeruli. The accumulating knowledge on how biologically relevant information is encoded in receptor and antennal lobe neurons in heliothines makes these moths particularly interesting for studying the functional organization of the glomeruli. The anatomical atlases of the antennal lobes, as presented here, are prerequisites for identifying glomeruli ascribed to particular functions across sexes and species.

The chemoreceptor superfamily in the honey bee, Apis mellifera: Expansion of the odorant, but not gustatory, receptor family

“…comm. ), and 60-66 for moths (Berg et al 2002;Ai and Kanzaki 2004;Skiri et al 2005) fits well with the enhanced olfactory range and discriminatory abilities of the honey bee. Drosophila olfactory receptor neurons (ORNs) generally express a single olfactory receptor protein (Or; in addition to the widely-expressed conserved DmOr83b), and each ORN expressing a particular Or converges on a single gomerulus in each antennal lobe, thereby allowing for a map of differential activation of suites of glomeruli to be interpreted in higher brain centers as a particular odor (see Vosshall et al 2000;Rutzler and Zwiebel 2005;Hallem et al 2006).…”

Morphological characterization of the antennal lobes in the Mediterranean fruit fly Ceratitis capitata

“…The aim of this study was to describe the glomerular morphology of the ALs in the Mediterranean fruit fly (Kanzaki et al 1989;Stocker et al 1990;Rospars and Hildebrand 1992;Galizia et al 1999;Laissue et al 1999;Chiang et al 2001;Berg et al 2002;Anton and Rospars 2004;Ignell et al 2005;Skiri et al 2005;Ghaninia et al 2007), which follow a common functional organization, but with a variable number across species (Rospars 1988;Schachtner et al 2005).…”

“…Knowing the spatial arrangement of glomeruli thus becomes a relevant step in elucidating the olfactory system of a particular species. For this reason, the glomerular organizations of the ALs have been studied and described in several insect species, such as Drosophila (Stocker et al 1990;Laissue et al 1999), moths (Kanzaki et al 1989;Rospars and Hildebrand 1992;Berg et al 2002;Skiri et al 2005), honeybees (Galizia et al 1999), mosquitoes (Anton and Rospars 2004;Ignell et al 2005;Ghaninia et al 2007), cockroaches (Chiang et al 2001) and beetles (Dreyer et al 2010;Hu et al 2011). This development has been strongly aided by the improvement of staining techniques based on fluorescent dyes, combined with confocal sectioning of whole-mount preparations, and the reconstruction of entire ALs by image analyses.…”

Heterogeneity in dendritic morphology of moth antennal lobe projection neurons

“…To analyze the morphology of a population of PNs, identification of glomeruli and intracellular labeling of single neurons are required. Ordinary glomeruli in the moth AL have been analyzed in detail, and an identification method for the glomeruli has been established (Berg et al, 2002;Sadek et al, 2002;Masante-Roca et al, 2002;Greiner et al, 2004;Skiri et al, 2005;Kazawa et al, 2009;Couton et al, 2009;Varela et al, 2009), as in the cases of other insects (Galizia et al, 1999;Laissue et al, 1999). Determination of the morphology of PNs in moths by using glomeruli identification has been reported with relatively small data sets (up to 40; Sun et al, 1997;Vickers et al, 1998;Sadek et al, 2002;Kanzaki et al, 2003;Han et al, 2005;Rø et al, 2007;Kvello et al, 2009;Løfaldli et al, 2010;Zhao and Berg, 2010).…”