High-fat diet impairs cognitive function of zebrafish

Area of Science:

• Neuroscience
• Comparative Biology
• Nutritional Science

Background:

• Excessive fat intake is linked to obesity and cognitive dysfunction in mammals.
• The effects of high-fat diets on cognitive function in zebrafish remain largely uninvestigated.

Purpose of the Study:

• To investigate the impact of a high-fat diet on cognitive function in zebrafish.
• To analyze gene expression changes in the zebrafish telencephalon in response to a high-fat diet.

Main Methods:

• Zebrafish were fed either a high-fat diet or a control diet.
• Cognitive function was assessed using an active avoidance test.
• Telencephalon gene expression was analyzed using RNA sequencing and quantitative real-time PCR.

Main Results:

• High-fat diet consumption significantly impaired cognitive function in zebrafish compared to controls.
• RNA sequencing identified 97 differentially expressed genes (fold change > 2, p < 0.05).
• Genes involved in neuronal activity, anti-oxidative stress, blood-brain barrier function, and amyloid-beta degradation were downregulated; genes related to apoptosis and amyloid-beta production were upregulated.

Conclusions:

• Dietary excessive fat intake negatively affects cognitive function in zebrafish.
• Gene expression changes observed in zebrafish mirror those in mammals fed high-fat diets.
• Zebrafish represent a viable animal model for studying dietary-induced cognitive impairment.