Details

Autor(en) / Beteiligte

• Zhang, De Lu
• Hu, Chun Xiang
• Li, Dun Hai
• Liu, Yong Ding

Titel

Zebrafish locomotor capacity and brain acetylcholinesterase activity is altered by Aphanizomenon flos-aquae DC-1 aphantoxins

Ist Teil von

• Aquatic toxicology, 2013-08, Vol.138-139, p.139-149

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• •Zebrafish touch response, locomotor and brain acetylcholinesterase activity were affected by A. flos-aquae DC-1 aphantoxins.•Abnormal motor pattern was found with mechanically swinging the head after wagging the tail after exposure.•Abnormal activity was found with more fish in upper or bottom and fewer in middle water with time and doses postexposure.•The pattern of touch response, movement and AChE was found from first change, accumulation to the maximum postexposure. Aphanizomenon flos-aquae (A. flos-aquae) is a source of neurotoxins known as aphantoxins or paralytic shellfish poisons (PSPs) that present a major threat to the environment and to human health. Generally, altered neurological function is reflected in behavior. Although the molecular mechanism of action of PSPs is well known, its neurobehavioral effects on adult zebrafish and its relationship with altered neurological functions are poorly understood. Aphantoxins purified from a natural isolate of A. flos-aquae DC-1 were analyzed by HPLC. The major analogs found in the toxins were the gonyautoxins 1 and 5 (GTX1 and GTX5; 34.04% and 21.28%, respectively) and the neosaxitoxin (neoSTX, 12.77%). Zebrafish (Danio rerio) were intraperitoneally injected with 5.3 and 7.61μg STXeq/kg (low and high dose, respectively) of A. flos-aquae DC-1 aphantoxins. The swimming activity was investigated by observation combined with video at 6 timepoints from 1 to 24h post-exposure. Both aphantoxin doses were associated with delayed touch responses, reduced head–tail locomotory abilities, inflexible turning of head, and a tailward-shifted center of gravity. The normal S-pattern (or undulating) locomotor trajectory was replaced by a mechanical motor pattern of swinging the head after wagging the tail. Finally, these fish principally distributed at the top and/or bottom water of the aquarium, and showed a clear polarized distribution pattern at 12h post-exposure. Further analysis of neurological function demonstrated that both aphantoxin doses inhibited brain acetylcholinesterase activity. All these changes were dose- and time-dependent. These results demonstrate that aphantoxins can alter locomotor capacity, touch responses and distribution patterns by damaging the cholinergic system of zebrafish, and suggest that zebrafish locomotor behavior and acetylcholinesterase can be used as indicators for investigating aphantoxins and blooms in nature.