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Behavioral alterations induced by repeated saxitoxin exposure in drinking water
Felipe Diehl1, Patricia Baptista Ramos2, Juliane Marques Dos Santos2
1Postgraduate Program in Physical, Chemical and Geological Oceanography, Institute of Oceanography, Federal University of Rio Grande (FURG), Rio Grande, RS Brazil ; Institute of Oceanography, Federal University of Rio Grande (FURG), Caixa Postal 474, Rio Grande, RS CEP 96203-900 Brazil.
Chronic exposure to saxitoxin from Cylindrospermopsis raciborskii in drinking water impaired memory in rats. This study investigated the long-term cognitive effects of saxitoxin contamination.
Area of Science:
- Environmental Toxicology
- Neuroscience
- Cyanobacterial Toxinology
Background:
- Cylindrospermopsis raciborskii blooms contaminate Brazilian drinking water reservoirs with saxitoxin.
- Chronic effects of repeated saxitoxin exposure require further investigation beyond known acute intoxication.
- Understanding long-term health impacts of cyanotoxins in water is crucial for public health.
Purpose of the Study:
- To investigate the effects of 30-day consumption of saxitoxin-contaminated drinking water on rat learning and memory.
- To assess potential cognitive deficits resulting from chronic exposure to saxitoxin (STX).
Main Methods:
- Rats were exposed to saxitoxin (3 or 9 μg/L STX equivalents) or cyanobacteria for 30 days.
- Behavioral assessments included open field habituation, elevated plus maze, inhibitory avoidance, and Morris water maze tasks.
- Evaluated parameters included anxiety, motor exploration, and spatial and aversive memory performance.
Main Results:
- No significant effects on anxiety or motor exploration were observed in the elevated plus maze and open field tasks.
- Rats exposed to 9 μg/L STX equivalents showed significantly decreased memory performance in inhibitory avoidance and Morris water maze tasks.
- A dose-dependent effect on memory impairment was suggested, with higher saxitoxin levels causing greater deficits.
Conclusions:
- Chronic saxitoxin exposure can induce amnesic effects on both aversive and spatial memory in rats.
- These findings highlight the potential neurotoxic risks of saxitoxin-contaminated drinking water on cognitive functions.
- Further research is warranted to elucidate the mechanisms underlying saxitoxin-induced memory impairment.
