Hippocampal long-term potentiation (LTP) is reduced by a coplanar PCB congener.
Neurotoxicity of polychlorinated biphenyls (PCBs) is usually ascribed to the ortho-substituted congeners. We have examined the effects of acute perfusion of 3,3',4,4'-tetrachlorobiphenyl (PCB 77), a coplanar, dioxin-like congener, on long-term potentiation (LTP) in the Schaffer collateral-CA1 and the mossy fiber-CA3 pathways in mouse hippocampus. LTP in both pathways was blocked by PCB 77, with a threshold effect at a concentration of 1 microM. LTP is a useful model of learning and memory function in which a patterned stimulation of an afferent pathway produces a persistent increase in the efficacy of synaptic transmission. LTP is reduced by PCB mixtures and ortho-substituted congeners at concentrations comparable to those studied here. These observations provide evidence in support of the hypothesis that dioxin-like and non-dioxin-like PCB congeners are equally potent in causing the cognitive decrements seen in children exposed prenatally to PCBs.
Ozcan
Mete
M
School of Public Health, University at Albany, One University Place, Rensselaer, NY 12144-3456, USA.
Yilmaz
Bayram
B
King
W Michael
WM
Carpenter
David O
DO
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D011078:Polychlorinated Biphenyls / Q000737:chemistry* / Q000494:pharmacology*
D011078:Polychlorinated Biphenyls