Effects of Great Lakes fish consumption on brain PCB pattern, concentration, and progressive-ratio performance

Area of Science:

• Environmental Toxicology
• Neuroscience
• Behavioral Pharmacology

Background:

• Great Lakes fish can accumulate organochlorine contaminants like polychlorinated biphenyls (PCBs).
• Exposure to environmental toxins can potentially impact neurological function and behavior.
• Understanding contaminant effects is crucial for public health advisories.

Purpose of the Study:

• To investigate the impact of Great Lakes fish consumption on rat brain contaminant levels.
• To assess the effects of these contaminants on progressive ratio performance.
• To analyze the relationship between brain contaminant concentrations and behavioral changes.

Main Methods:

• Adult male Sprague-Dawley rats were fed diets containing Lake Ontario salmon, Pacific Ocean salmon, or control chow for 20 or 65 days.
• Organochlorine contaminants (PCBs, DDE, mirex) in brain tissue were analyzed using gas chromatography.
• Behavioral testing involved a multiple fixed-ratio-progressive-ratio reinforcement schedule to measure persistence.

Main Results:

• Lake Ontario fish consumption significantly elevated brain concentrations of PCBs, DDE, and mirex compared to controls.
• Rats fed Lake Ontario fish exhibited a more heavily chlorinated PCB pattern in their brains.
• Lake Ontario fish-fed rats showed significantly reduced persistence on a progressive-ratio schedule, indicating decreased behavioral persistence.

Conclusions:

• Consumption of contaminated Great Lakes fish leads to increased brain organochlorine contaminant levels and altered PCB congener profiles in rats.
• These contaminant increases are associated with reduced persistence in behavioral tasks, suggesting a link to neurological effects.
• Further research is needed to definitively attribute behavioral changes to specific contaminants like PCBs.