title: Investigation of spatial trends and neurochemical impacts of mercury in herring  gulls across the Laurentian Great Lakes.
abstract: Herring gulls (Larus argentatus) bioaccumulate mercury (Hg) but it is unknown whether they are exposed at levels of neurological concern. Here we studied brain tissues from gulls at five Great Lakes colonies and one non-Great Lakes colony during spring of 2001 and 2003. Total brain Hg concentrations ranged from 0.14 to 2.0 microg/g (dry weight) with a mean of 0.54 microg/g. Gulls from Scotch Bonnet Island, on the easternmost edge of the Great Lakes, had significantly higher brain Hg than other colonies. No association was found between brain Hg concentration and [3H]-ligand binding to neurochemical receptors (N-methyl-D-aspartate, muscarinic cholinergic, nicotinic cholinergic) or nicotinic receptor alpha-7 relative mRNA expression as previously documented in other wildlife. In conclusion, spatial trends in Hg contamination exist in herring gulls across the Great Lakes basin, and herring gulls accumulate brain Hg but not at levels associated with sub-clinical neurochemical alterations.
authors.affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory St, Ann Arbor, MI 48109, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rutkiewicz
authors.forename: Anton
authors.initials: A
authors.lastname: Scheuhammer
authors.forename: Doug
authors.initials: D
authors.lastname: Crump
authors.forename: Magdalena
authors.initials: M
authors.lastname: Jagla
authors.forename: Niladri
authors.initials: N
authors.lastname: Basu
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D046091:Charadriiformes / Q000378:metabolism*; D004784:Environmental Monitoring; D006114:Great Lakes Region; D008628:Mercury / Q000378:metabolism* / Q000633:toxicity; D016202:N-Methylaspartate / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D012333:RNA, Messenger; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D014874:Water Pollutants, Chemical; D016202:N-Methylaspartate; D008628:Mercury