title: Alterations in the levels and distribution of octopamine in the central nervous system and ovary of the Pacific white shrimp, Litopenaeus vannamei, and its possible role in ovarian development.
abstract: Octopamine (OA) is a major neurotransmitter that has not been studied in the Pacific white shrimp, Litopenaeus vannamei. Therefore, we investigated changes in OA levels, its distribution in regions of the central nervous system (CNS) and ovary during the ovarian maturation cycle, as well as its possible role in regulating ovarian maturation. OA exhibited the highest concentration in the brain and thoracic ganglia at ovarian stage II, and then declined to the lowest concentration at ovarian stages III and IV. In the cerebral ganglia, OA-immunoreactivity (OA-ir) was present in neurons of clusters 6, 17, the anterior and posterior medial protocerebral, olfactory, antenna II, and tegumentary neuropils. In the circumesophageal, subesophageal, thoracic ganglia and abdominal ganglia, OA-ir was detected in several neuropils, neurons and fibers. The high level of intensity in OA immunostaining was observed in early developmental stage of oocyte by comparison with low level of OA-ir in late stages of oocyte development. Functionally, OA-injected female shrimps at doses of 2.5×10(-7) and 2.5×10(-6)mol/shrimp, showed significantly decreased gonado-somatic indices, oocyte diameters, and hemolymph vitellogenin levels, compared with control groups. This study showed changes of OA in the CNS and ovary reaching the highest level in early ovarian stages and declining in late stages, and it decreased hemolymph vitellogenin levels, suggesting significant involvement of OA in female reproduction in this species.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Mahidol University, Nakhonsawan Campus, Nakhonsawan 60130, Thailand. Electronic address: anatch2002@yahoo.com.
authors.forename: Yotsawan
authors.initials: Y
authors.lastname: Tinikul
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Mahidol University, Nakhonsawan Campus, Nakhonsawan 60130, Thailand.
authors.forename: Jaruwan
authors.initials: J
authors.lastname: Poljaroen
authors.affiliation: Mahidol University, Nakhonsawan Campus, Nakhonsawan 60130, Thailand.
authors.forename: Ruchanok
authors.initials: R
authors.lastname: Tinikul
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Mahidol University, Nakhonsawan Campus, Nakhonsawan 60130, Thailand.
authors.forename: Charoonroj
authors.initials: C
authors.lastname: Chotwiwatthanakun
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Agricultural Science Division, Mahidol University, Kanchanaburi Campus, Saiyok, Kanchanaburi 71150, Thailand.
authors.forename: Panat
authors.initials: P
authors.lastname: Anuracpreeda
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Pro Vice-Chancellor's Office, Faculty of Science and Technology, Deakin University, Locked Bay 20000, Geelong, VIC 3220, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hanna
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D005260:Female; D006458:Hemolymph / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009655:Octopamine / Q000378:metabolism*; D009866:Oogenesis / Q000502:physiology; D010053:Ovary / Q000254:growth & development* / Q000378:metabolism*; D033561:Penaeidae / Q000254:growth & development / Q000378:metabolism; D014819:Vitellogenins / Q000032:analysis / Q000378:metabolism
chemical_list: D014819:Vitellogenins; D009655:Octopamine
keywords: Central nervous system; Litopenaeus vannamei; Octopamine; Ovarian development; Vitellogenin