title: Revisiting the anatomy of the central nervous system of a hemimetabolous model insect species: the pea aphid Acyrthosiphon pisum.
abstract: Aphids show a marked phenotypic plasticity, producing asexual or sexual and winged or wingless morphs depending on environmental conditions and season. We describe here the general structure of the brain of various morphs of the pea aphid Acyrthosiphon pisum. This is the first detailed anatomical study of the central nervous system of an aphid by immunocytochemistry (synapsin, serotonin, and several neuropeptides), ethyl-gallate staining, confocal laser scanning microscopy, and three-dimensional reconstructions. The study has revealed well-developed optic lobes composed of lamina, medulla, and lobula complex. Ocelli are only present in males and winged parthenogenetic females. The central complex is well-defined, with a central body divided into two parts, a protocerebral bridge, and affiliated lateral accessory lobes. The mushroom bodies are ill-defined, lacking calyces, and only being visualized by using an antiserum against the neuropeptide orcokinin. The antennal lobes contain poorly delineated glomeruli but can be clearly visualized by performing antennal backfills. On the basis of our detailed description of the brain of winged and wingless parthenogenetic A. pisum females, an anatomical map is now available that should improve our knowledge of the way that these structures are involved in the regulation of phenotypic plasticity.
authors.affiliation: Department of Biology - Animal Physiology, Philipps University Marburg, 35043, Marburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kollmann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Minoli
authors.forename: Joël
authors.initials: J
authors.lastname: Bonhomme
authors.forename: Uwe
authors.initials: U
authors.lastname: Homberg
authors.forename: Joachim
authors.initials: J
authors.lastname: Schachtner
authors.forename: Denis
authors.initials: D
authors.lastname: Tagu
authors.forename: Sylvia
authors.initials: S
authors.lastname: Anton
mesh_terms: D000818:Animals; D001042:Aphids / Q000033:anatomy & histology* / Q000502:physiology; D019521:Body Patterning; D002490:Central Nervous System / Q000033:anatomy & histology; D005260:Female; D007313:Insecta; D008297:Male; D009899:Optic Lobe, Nonmammalian / Q000033:anatomy & histology; D010312:Parthenogenesis; D018532:Pisum sativum / Q000469:parasitology; D010641:Phenotype