Impacts of neonatal methylmercury on behavioral flexibility and learning in spatial discrimination reversal and visual signal detection tasks.

Autor: Kendricks DR; Department of Psychological Sciences, Auburn University, Auburn, AL, USA., Bhattacharya S; Keck Graduate Institute, School of Pharmacy and Health Sciences, Claremont Colleges, Claremont, CA, USA., Reed MN; Department of Drug Discovery and Development, Auburn University, Auburn, AL, USA; Center for Neuroscience Initiative, Auburn University, Auburn, AL, USA., Newland MC; Department of Psychological Sciences, Auburn University, Auburn, AL, USA. Electronic address: newlamc@auburn.edu.
Jazyk: angličtina
Zdroj: Neurotoxicology [Neurotoxicology] 2022 Dec; Vol. 93, pp. 9-21. Date of Electronic Publication: 2022 Aug 30.
DOI: 10.1016/j.neuro.2022.08.013
Abstrakt: Early postnatal development in rodents is sensitive to neurotoxic effects of the environmental contaminant, methylmercury. While juvenile and adolescent exposure also produce long-term impairments in behavior, the outcome of neonatal exposure is less understood. Neural development during the neonatal period in rodents is akin to that seen in humans during the third trimester of pregnancy but methylmercury exposure occurring during the neonatal period has not been modeled, partly because breast milk is a poor source of bioavailable methylmercury. To examine this developmental period, male Long-Evans rats were exposed to 0, 80, or 350 µg/kg/day methylmercuric chloride from postnatal days 1-10, the rodent neonatal period. As adults, behavioral flexibility, attention, memory, and expression of the dopamine transporter in these rats was assessed. Rats exhibited changes in behavioral flexibility assessed in a spatial discrimination reversal procedure. Those rats exposed to the highest dose of methylmercury displayed subtly altered patterns of perseveration compared to control animals. During acquisition of the attention/memory procedure, rats exposed to this dose also had slower acquisition, and achieved lower overall accuracy during training, compared to controls despite neither attention nor memory being affected once the task was acquired. Finally, dopamine transporter expression in the striatum, prefrontal cortex, and hippocampus was unchanged in these adult rats. The results of this study replicate the trend of findings seen with exposure during gestation or during adolescence.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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