Polychlorinated biphenyls (PCBs) selectively disrupt serotonergic cell growth in the developing Spisula embryo

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that exert neurotoxic effects during embryonic development, The present stu dy demonstrates that early embryonic exposure to a mixture of PCBs (Aroclor 1254) results in a decrease in serotonergic cell growth. Using a novel, ma rine invertebrate embryo model, Spisula solidissima, immunocytochemistry, a nd confocal microscopy techniques,a dose-dependent decrease in serotonergic cell number was quantified within 24 h of exposure. This effect wins seen with doses as low as 1 ppm Aroclor 1254. These findings demonstrate that en vironmentally relevant doses of Aroclor 1254 impair development of the sero tonergic nervous system.