title: Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar).
abstract: Aluminum (Al) toxicity occurs frequently in natural aquatic ecosystems as a result of acid deposition and natural weathering processes. Detrimental effects of Al toxicity on aquatic organisms are well known and can have consequences for survival. Fish exposed to Al in low pH waters will experience physiological and neuroendocrine changes that disrupt homeostasis and alter behavior. To investigate the effects of Al exposure on both the brain and behavior, Atlantic salmon (Salmo salar) kept in water treated with Al (pH 5.7, 0.37±0.04 μmol 1(-1) Al) for 2 weeks were compared with fish kept in under control conditions (pH 6.7, <0.04 μmol 1(-1) Al). Fish exposed to Al and acidic conditions had increased Al accumulation in the gills and decreased gill Na(+), K(+)-ATPase activity, which impaired osmoregulatory capacity and caused physiological stress, indicated by elevated plasma cortisol and glucose levels. Here we show for the first time that exposure to Al in acidic conditions also impaired learning performance in a maze task. Al toxicity also reduced the expression of NeuroD1 transcript levels in the forebrain of exposed fish. As in mammals, these data show that exposure to chronic stress, such as acidified Al, can reduce neural plasticity during behavioral challenges in salmon, and may impair the ability to cope with new environments.
authors: Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA 16802, USA. ocg102@psu.edu
authors: C
authors: C
authors: Grassie
authors: V A
authors: VA
authors: Braithwaite
authors: J
authors: J
authors: Nilsson
authors: T O
authors: TO
authors: Nilsen
authors: H-C
authors: HC
authors: Teien
authors: S O
authors: SO
authors: Handeland
authors: S O
authors: SO
authors: Stefansson
authors: V
authors: V
authors: Tronci
authors: M
authors: M
authors: Gorissen
authors: G
authors: G
authors: Flik
authors: L O E
authors: LO
authors: Ebbesson
mesh_terms: D000535:Aluminum / Q000633:toxicity*; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001522:Behavior, Animal / Q000187:drug effects*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004781:Environmental Exposure; D005786:Gene Expression Regulation / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009473:Neuronal Plasticity / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020317:Salmo salar / Q000033:anatomy & histology / Q000097:blood / Q000235:genetics / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D060753:Water Quality
chemical_list: D000535:Aluminum; D051792:Basic Helix-Loop-Helix Proteins; D001786:Blood Glucose; D006854:Hydrocortisone; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D000254:Sodium-Potassium-Exchanging ATPase; C093564:Neurogenic differentiation factor 1
keywords: chronic mild stress; parr–smolt transformation; physiology; salmonid; spatial learning; telencephalon