Maternal Rat Periapical Abscesses Affect Brain Norepinephrine Levels in Offspring

Objective: The objective of this study is to determine the effect of maternal tooth abscesses on the neonatal brain development in a rat model. Methods: Sprague-Dawley rats were divided into two groups: pregnant rats with induced pulpal inflammation (n=7) and sham-operated control pregnant rats (n=8). The pulps of the first and second maxillary right molars were exposed using a ¼ round burr. Once bleeding ceased 0.5ml of bacterial lipopolysaccharide (LPS) was then placed into each pulp chamber. Rats became pregnant 2 weeks following pulp exposure. Following delivery of the pups (experimental group N=99, control group N=101), brain samples were collected from the pups and were ground in PBS containing a protease inhibitor (10mg/ml) and norepinephrine levels were determined by ELISA. Data were compared by factorial analysis of variance and a post-hoc Tukey test and Pearson's correlation test. Results: Pups born of mothers with periapical abscesses were significantly heavier (p<0.001) and had significantly lower concentrations of norepinephrine (p<0.001). The mothers had significantly higher serum concentrations of TNF-alpha and IL-6 (p<0.001). Pup birthweight and brain norepinephrine concentrations were significantly correlated with maternal periapical abscesses (p<0.001). Maternal serum IL-6 was significantly correlated with pup brain norepinephrine (p<0.05) and birthweight (p<0.05). Conclusion: The significantly decreased concentration of norepinephrine in the brains of the pups born to mothers with periapical abscesses suggests that there is an adverse effect of the abscesses on the developing brain of these pups. Further testing is needed to determine how this decrease in norepinephrine would affect the pups' growth and development into adolescence, including possible adverse neurological consequences.