Prenatal nicotine exposure in mice induces sex-dependent anxiety-like behavior, cognitive deficits, hyperactivity, and changes in the expression of glutamate receptor associated-genes in the prefrontal cortex.
Pharmacol Biochem Behav. 2020 May 18;:172951
Authors: Polli FS, Scharff MB, Ipsen TH, Aznar S, Kohlmeier KA, Andreasen JT
In rodents, prenatal nicotine exposure (PNE) has been associated with increased risk for development of cognitive and emotional disturbances, but the findings are somewhat conflicting. Lack of behavioral alterations following PNE could be due to the variety of methods available for nicotine delivery, exposure time and species used, with inbred strains being mostly employed. Such differences suggest the need to investigate the behavioral phenotype in each PNE model available if we are to find models with enhanced translational value. In this study, we assessed sex-based effects of PNE on ADHD-related behaviors in mice and on the levels of mRNA coding for glutamate receptor subunits within the prefrontal cortex in the outbred NMRI mice exposed to nicotine via maternal drinking water during gestation. Cotinine levels were assessed in newborn pups. Behaviors related to anxiety, compulsivity, working memory, and locomotion were evaluated in both sexes of young adult offspring using the elevated zero maze, marble burying, spontaneous alternation behavior, and locomotor activity tests. Expression of mRNA coding for different glutamate receptors subunits within the prefrontal cortex (PFC) was measured using RT-qPCR. Cotinine levels in the serum of newborns confirmed fetal nicotine exposure. Both male and female offspring showed ADHD-like behaviors, such as deficit in the SAB test and hyperactivity. In addition, PNE male mice displayed anxiety- and compulsive-like behaviors, effects that were absent in female offspring. Finally, PNE reduced the expression of GluN1-, GluN2B-, and mGluR2-related genes within the PFC of male offspring. PNE in NMRI mice induced sex-dependent behavioral changes, which parallels clinical findings following maternal cigarette smoke exposure. Alterations detected in PFC mRNA glutamate receptor proteins could contribute to the abnormal behavioral responses observed in males, but other signaling pathways or brain regions are likely involved in the behavioral susceptibility of PNE individuals.
PMID: 32439454 [PubMed – as supplied by publisher]