Developmental exposure to polychlorinated biphenyls PCB153 or PCB126 impairs learning ability in young but not in adult rats.
Polychlorinated biphenyls (PCBs) are persistent organic pollutants present in the food chain and in human blood and milk. Exposure to PCBs during pregnancy and lactation leads to cognitive impairment in children. The underlying mechanisms remain unclear. Some PCBs are endocrine disrupters. The aim of this work was to assess whether exposure of rats to PCB126 (dioxin-like) or PCB153 (non-dioxin-like) during pregnancy and lactation affects the ability of the pups to learn a Y maze conditional discrimination task and/or the function of the glutamate-nitric oxide (NO)-cGMP pathway in brain in vivo when the rats are young (3 months) or adult (7-8 months). After finishing the learning experiments, the function of the pathway was analysed in the same rats by in vivo brain microdialysis. The results obtained show that perinatal exposure to PCB153 or PCB126: (1) impairs learning ability in young but not in adult rats, (2) impairs the glutamate-NO-cGMP pathway function in cerebellum in vivo in young but not in adult rats and (3) affect these parameters in males and females similarly. PCB126 is around 10 000-fold more potent than PCB153. In control rats the function of the glutamate-NO-cGMP pathway and learning ability are lower in adult than in young rats. These age-related differences are not present in rats exposed to PCBs. The impairment of the glutamate-NO-cGMP pathway function induced at young age by developmental exposure to the PCBs could be one of the mechanisms contributing to the cognitive impairment found in children whose mothers ingested PCB-contaminated food during pregnancy and lactation.
Piedrafita
Blanca
B
Laboratory of Neurobiology, Centro de Investigacion Príncipe Felipe, Avda Autopista del Saler 16, 46013 Valencia, Spain.
Erceg
Slaven
S
Cauli
Omar
O
Monfort
Pilar
P
Felipo
Vicente
V
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects; D002531:Cerebellum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004622:Embryo, Mammalian; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D007859:Learning Disabilities / Q000139:chemically induced*; D018782:Maze Learning / Q000187:drug effects; D017942:Nitric Acid / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017208:Rats, Wistar
D018698:Glutamic Acid; D017942:Nitric Acid; D011078:Polychlorinated Biphenyls; D006152:Cyclic GMP; C023035:3,4,5,3',4'-pentachlorobiphenyl; C014024:2,4,5,2',4',5'-hexachlorobiphenyl