The Effect Of B[a]P On The Neurobehavioral Developmental Of Neonatal Sprague Dawley Rats

Previous studies have demonstrated that benzo[a]pyrene (B[a]P) maydisrupt the neuro-development of key biological systems, thus leavingchildren more vulnerable to functional impairments in adulthood. Thecurrent study was conducted to determine whether neurotoxic effects ofpostnatal B[a]P exposure on behavioral performance persist in juvenile andyoung adult stages. Therefore, neonate Sprague-Dawley pups were givenoral doses of B[a]P (0.02,0.2, and2mg/kg/day) continuing through aperiod of rapid brain development (on postnatal days5-11). Further,developmental milestones and behavioral endpoints assessing sensory andmotor maturation were examined. Also, in this study, Morris water mazeand elevated plus maze were used for evaluating the cognitive function andanxiety-like behavior. Our results showed that there was altered ontogenyin a few measures of neuromotor development; however, otherdevelopmental milestones and sensory responses were not alteredsignificantly. Moreover, the hyperactivity in B[a]P-treated pups wasevident at PND36, and was most pronounced in the PND69. Also, exposure to B[a]P during early postnatal development had an adverse effect on adultrats (PND70) in the elevated plus maze, and the swim maze suggest thatlow doses of B[a]P impair short-term learning and spatial memoryfunctions at PND71. In contrast, B[a]P exposure had no evident effect onbehaviors in these two mazes for adolescent animals. These data clearlyindicate that behavioral impairments resulting from postnatal B[a]Pexposure are potentially long-lasting, may not be apparent in juveniles, butpresent in young adulthood.