title: Pheromone detection by a pheromone emitter: a small sex pheromone-specific processing system in the female American cockroach.
abstract: Many animals depend on pheromone communication for successful mating. Sex pheromone in insects is usually released by females to attract males. In American cockroaches, the largest glomerulus (B-glomerulus) in the male antennal lobe (first-order olfactory center) processes the major component of sex pheromone. Using intracellular recordings combined with fine neuroanatomical techniques, we provide evidence that the female homolog of the male B-glomerulus also acts as a sex pheromone-specific detector. Whereas ordinary glomeruli that process normal environmental odors are innervated by single projection neurons (PNs), the B-glomerulus in both sexes is innervated by multiple PNs, one of which possesses a thicker axon, termed here B-PN. Both soma size and axon diameter were smaller on B-PNs from females compared with B-PNs from males. The female B-PNs also produce fewer terminal arborizations in the protocerebrum than male B-PNs. Termination fields in the lateral protocerebrum of the female B-PN are mostly segregated from those formed by other uniglomerular PNs innervating ordinary glomeruli. Female B-PN activity was greatest in response to sex pheromone but lower than that in the male B-PN. This specific detection system suggests that sex pheromone affects the behavior and/or endocrine system of female cockroaches.
authors.affiliation: Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan. nishino@es.hokudai.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishino
authors.forename: Masazumi
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Mizunami
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D005260:Female; D005456:Fluorescent Dyes; D008297:Male; D018613:Microscopy, Confocal; D009833:Olfactory Pathways / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000502:physiology*; D010526:Periplaneta / Q000502:physiology*; D012724:Sex Attractants / Q000737:chemistry / Q000502:physiology*
chemical_list: D005456:Fluorescent Dyes; D012724:Sex Attractants