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

Abstract

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

A new invertebrate member of the p53 gene family is developmentally expressed and responds to polychlorinated biphenyls.

“…We also plan to determine whether decreased p120 levels and function are restricted to the nervous system. Because we have shown in separate experiments that PCBs target neuronal growth in surf clams (16,17) and that the time course of this reduction is the same for both p120 and the serotonergic system, we hypothesize that the developing nervous system is most sensitive to changes in p120.…”

“…All animals were maintained and handled in accordance with policies of the Institutional Animal Care and Use Committee at the MBL. Standard surf clam in vitro fertilization and culture methods were used (16). At the swimming blastula stage, embryos were transferred to 4-L aerated tanks at a concentration of 100 mL.…”

“…PCBs are lipophilic, environmentally pervasive chemicals that accumulate in plant, animal, and human tissues, promote tumor formation, can damage DNA (14,15), and induce neurotoxic effects during early development in clams (16,17) and humans (18). In vitro fertilization and subsequent developmental studies are easily conducted in the surf clam, Spisula solidissima (16,17,(19)(20)(21), but to our knowledge are not successful in either soft-shell clam or squid. During investigation of these embryos we partially cloned, sequenced, and generated a multiple alignment for a new member of the p53 gene family that codes for an exclusively embryonic 120-kD protein.…”

Aroclor 1254 inhibits tryptophan hydroxylase activity in rat brain

“…PCBs have been shown to impair serotonergic and other monoamine neurotransmitter systems in animal models as diverse as mammals, fish and clams (Chu et al 1996; Thomas 1997, 2001;Seegal et al 1985Seegal et al , 1986Seegal et al , 1990Seegal et al , 1991aSmith et al 1999). Several laboratory studies in rats have shown that PCBs at sub-lethal doses influence dopamine (DA), norepinephrine, serotonin (5-hydroxytryptamine, 5-HT), and their metabolite concentrations in discrete brain areas (Chu et al 1996;Seegal et al 1985Seegal et al , 1986Seegal et al , 1991a.…”

Vitamin E co-treatment reduces Aroclor 1254-induced impairment of reproductive neuroendocrine function in Atlantic croaker

“…Polychlorinated biphenyls (PCBs) have been shown to impair serotonergic and other monoamine neurotransmitter systems in animal models as diverse as mammals, fish and clams (Khan & Thomas, 1997, 2001Seegal, Brosch, & Bush, 1986;Smith, Barker, Barker, Jessen-Eller, & Reinisch, 1999). Some PCBs reduce serotonin (5-hydroxytryptamine; 5-HT) concentrations in certain brain areas in rats (Seegal et al, 1986) and fish (Khan & Thomas, 1997, 2001.…”