Maternal nicotine exposure during lactation alters food preference, anxiety-like behavior and the brain dopaminergic reward system in the adult rat offspring

- Brain reward system in adult life is changed by exposure to nicotine during lactation.
- Early exposure to nicotine increases preference for sugar in adult life.
- Nicotine exposure decreases dopaminergic action in the nucleus accumbens.
- Nicotine exposure reduces dopaminergic action in the arcuate nucleus.
- Obese rats that were exposed to nicotine present higher anxiety levels at adulthood.

The mesolimbic reward pathway is activated by drugs of abuse and palatable food, causing a sense of pleasure, which promotes further consumption of these substances. Children whose parents smoke are more vulnerable to present addictive-like behavior to drugs and food. We evaluated the association between maternal nicotine exposure during lactation with changes in feeding, behavior and in the dopaminergic reward system. On postnatal day (PN) 2, Wistar rat dams were implanted with minipumps releasing nicotine (N; 6 mg/kg/day, s.c.) or saline (C) for 14 days. On PN150 and PN160, offspring were divided into 4 groups for a food challenge: N and C that received standard chow (SC); and N and C that could freely self-select (SSD) between high-fat and high-sugar diets (HFD and HSD, respectively). Offspring were tested in the elevated plus maze (EPM) and open field (OF) arena on PN152-153. On PN170, offspring were euthanized for central dopaminergic analysis. SSD animals showed an increased food intake compared to SC ones and a preference for HFD. However, N-SSD animals consumed relatively more HSD than C-SSD ones. Regarding behavior, N animals showed an increase in the time spent in the EPM center and a reduction in relative activity in the OF center. N offspring presented lower dopamine receptor (D2R) and transporter (DAT) contents in the nucleus accumbens, and lower D2R in the arcuate nucleus. Postnatal exposure to nicotine increases preference for sugar and anxiety levels in the adult progeny possibly due to a decrease in dopaminergic action in the nucleus accumbens and arcuate nucleus.