Neurobehavioral Alterations in Zebrafish Due to Long-Term Exposure to Low Doses of Inorganic Arsenic

Abstract

Inorganic arsenic (As) is one of the most ubiquitous and toxic substances with widespread health effects on human populations and biodiversity. Although arsenic is a frequent surface water pollutant, there is scant evidence about neurotoxicity in aquatic species in different stages of development. In the present study, we investigated the neurobehavioral effects of chronic exposure to environmentally relevant doses of arsenic. We exposed zebrafish to 50 and 500 ppb during the larval, juvenile, and adult stage (from 4 h to 150 days postfertilization). We then used broad behavioral screening to evaluate motor function, social behavior, learning and memory, and anxiety-like behaviors. Our results show that arsenic exposure to 500 ppb alters motor function from the embryo to the adult stage. Furthermore, during the adult phase, associative learning and the sensorimotor response are affected with both high and low doses of As, respectively. Notably, exposure to 500 ppb of As induces behaviors associated with anxiety, during the juvenile and adult phase but not the larval stage, without changes in whole-body cortisol levels. These results indicate that chronic exposure to arsenic during their lifespan is capable of producing alterations in different behavioral markers in aquatic vertebrates.

Zebrafish Larvae as a Behavioral Model in Neuropharmacology

“…Zebrafish larvae are also increasingly used for studying the behavioral toxicity of environmental toxicants [88,89,90,98,102]. The study of toxicants-induced behavior alteration in zebrafish larvae is important as it not only provides their effect in aquatic life, but also gives a clue about the neurobehavioral effects they cause in the broader ecosystem, including humans.…”

“…Some environmental toxicants showed neurobehavioral alterations similar to those observed in rodent models. For instance, arsenic showed increased locomotor activity [98] and tributyltin significantly reduced the locomotor activity [103] in zebrafish larvae. These effects were similar to that described in the rodent models where arsenic is shown to cause an increase in locomotor activity [98] and tributyltin is shown to cause a dose-dependent decrease in spontaneous motor activity [117].…”

“…For instance, arsenic showed increased locomotor activity [98] and tributyltin significantly reduced the locomotor activity [103] in zebrafish larvae. These effects were similar to that described in the rodent models where arsenic is shown to cause an increase in locomotor activity [98] and tributyltin is shown to cause a dose-dependent decrease in spontaneous motor activity [117]. Thus, the light-dark locomotion test in zebrafish larvae has been successfully employed for the study of neurobehavioral alterations caused by various environmental toxicants.…”

Acute net stress of young adult zebrafish (Danio rerio) is not sufficient to increase anxiety-like behavior and whole-body cortisol

“…Although many studies have investigated the effects brought upon by different stressors, literature in this field is typically limited to effects observed in either larval fish or during adulthood. Fewer studies have investigated stress regulation around the time of sexual maturation and in the young adult period (Alsop & Vijayan, 2009b; Baiamonte et al, 2016; Dipp et al, 2018; Forsatkar et al, 2017; Petrunich-Rutherford, 2019). Additional investigation of external factors and underlying mechanisms that mediate the effects of stress in the zebrafish can be used to further develop this animal as a practical model in neuroscience and further the current understandings of the plasticity and vulnerability of the stress response around the time of sexual maturation.…”

Mutagenicity assessment downstream of oil and gas produced water discharges intended for agricultural beneficial reuse

“…Thus, it is possible that different results would have been observed if holding time was decreased. Previous studies have observed developmental toxicity in zebrafish exposed to metals, including arsenic, cadmium and aluminum, all of which were detected in the PW discharge stream (Beaver et al, 2017;Dipp et al, 2018;Capriello et al, 2019). This indicates that concentrations of these species were not high enough in the samples analyzed to increase EPR and LPR in zebrafish.…”