Cholinergic system and exploratory behavior are changed after weekly-binge ethanol exposure in zebrafish

Area of Science:

• Neuroscience
• Toxicology
• Behavioral Science

Background:

• Binge drinking negatively impacts quality of life.
• Zebrafish are a valuable model for studying ethanol (EtOH) effects.
• Research on binge EtOH exposure in zebrafish is limited.

Purpose of the Study:

• To investigate neurobehavioral impairments from binge EtOH exposure in zebrafish.
• To analyze neurochemical and behavioral changes following repeated EtOH immersion.

Main Methods:

• Zebrafish were immersed in 1.4% EtOH three times weekly.
• Neurobehavioral parameters were assessed immediately, 2, and 9 days post-exposure.
• Brain enzyme activities (ChAT, AChE, antioxidant enzymes) and gene expression were measured.

Main Results:

• Brain choline acetyltransferase and acetylcholinesterase activities decreased 9 days post-EtOH.
• Oxidative stress markers (TBARS, DCF) increased immediately but normalized by day 2.
• Catalase and glutathione reductase were impaired 2 and 9 days post-EtOH.
• No changes in inflammatory gene expression (il-1β, il-10, tnf-α) were observed.
• Anxiolytic-like behavior was seen immediately post-exposure, but not at 9 days.

Conclusions:

• Binge EtOH exposure induces long-lasting cholinergic alterations in zebrafish brains.
• These alterations are likely linked to initial oxidative stress, not inflammation.
• Zebrafish serve as a relevant model for studying binge alcohol's neurobiological consequences.