CO2-induced ocean acidification increases anxiety in Rockfish via alteration of GABAA receptor functioning

TitleCO2-induced ocean acidification increases anxiety in Rockfish via alteration of GABAA receptor functioning
Publication TypeJournal Article
Year of Publication2014
AuthorsHamilton T.J, Holcombe A., Tresguerres M
JournalProc Biol SciProc Biol Sci
Date Published2013/11
ISBN Number1471-2954 (Electronic)<br/>0962-8452 (Linking)
Accession Number24285203

The average surface pH of the ocean is dropping at a rapid rate due to the dissolution of anthropogenic CO2, raising concerns for marine life. Additionally, some coastal areas periodically experience upwelling of CO2-enriched water with reduced pH. Previous research has demonstrated ocean acidification (OA)-induced changes in behavioural and sensory systems including olfaction, which is due to altered function of neural gamma-aminobutyric acid type A (GABAA) receptors. Here, we used a camera-based tracking software system to examine whether OA-dependent changes in GABAA receptors affect anxiety in juvenile Californian rockfish (Sebastes diploproa). Anxiety was estimated using behavioural tests that measure light/dark preference (scototaxis) and proximity to an object. After one week in OA conditions projected for the next century in the California shore (1125 +/- 100 microatm, pH 7.75), anxiety was significantly increased relative to controls (483 +/- 40 microatm CO2, pH 8.1). The GABAA-receptor agonist muscimol, but not the antagonist gabazine, caused a significant increase in anxiety consistent with altered Cl(-) flux in OA-exposed fish. OA-exposed fish remained more anxious even after 7 days back in control seawater; however, they resumed their normal behaviour by day 12. These results show that OA could severely alter rockfish behaviour; however, this effect is reversible.

Short TitleProceedings. Biological sciences / The Royal SocietyProceedings. Biological sciences / The Royal Society
Alternate JournalProceedings. Biological sciences / The Royal Society
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