Cu disrupts the olfacto-retinal centrifugal pathway and mediates reduced feeding-related behavior in zebrafish (Danio rerio).

Copper exposure significantly impairs olfactory signal transduction and reduces feeding-related behavior in zebrafish, with up to a 56% decrease in olfactory function.

• Why it matters: Understanding how environmental copper affects sensory and feeding behaviors in fish is crucial for assessing ecological risks of contamination, especially given copper's widespread presence.
• What they did: Six-month-old zebrafish were exposed to copper concentrations of 1.6, 5.6, 16, and 35 μg/L over 30 days, with behavioral, neurochemical, and transcriptional biomarkers measured to evaluate toxic effects.
• The result: Copper accumulated in olfactory tissues, eyes, and brains, causing sex-dependent impairments in olfactory and visual functions, altered neurotransmitter levels, and a 6.0-17% decline in feeding behavior, suggesting disrupted sensory pathways and appetite regulation.