Long-Term Memory Function Impairments following Sucrose Exposure in Juvenile versus Adult Rats

Area of Science:

• Neuroscience
• Metabolic Science
• Behavioral Science

Background:

• Excessive sucrose consumption in youth has been linked to fear memory and anxiety-like behaviors in adulthood.
• The impact of early sucrose intake on higher cognitive functions, such as recognition memory, remains less understood.

Purpose of the Study:

• To investigate the long-term effects of juvenile sucrose consumption on object recognition memory (NOR) in adult rats.
• To assess the relationship between sucrose intake, metabolic changes, and cognitive performance.

Main Methods:

• Male Sprague Dawley rats received unlimited sucrose access during juvenile (PD 25-50) or adult (PD 75-100) stages.
• Object recognition memory was tested at short-term (2h), long-term (24h), and consolidated (7 days) intervals.
• Metabolic parameters (hypertriglyceridemia, glucose intolerance, glycemia) and hippocampal proBDNF and RAGE expression were analyzed.

Main Results:

• Rats exposed to sucrose during juvenile development exhibited impaired object recognition memory compared to controls and adult-exposed rats.
• Sucrose consumption led to hypertriglyceridemia and glucose intolerance in all exposed groups.
• Juvenile sucrose exposure resulted in increased fasting glycemia, sustained glucose intolerance, decreased hippocampal proBDNF, and increased RAGE expression in adults.
• Object recognition memory performance correlated negatively with basal glycemia and positively with proBDNF levels.

Conclusions:

• Early-life excessive sucrose intake can lead to long-term deficits in recognition memory.
• Alterations in glucose metabolism and proBDNF expression appear to mediate the negative cognitive effects of early sucrose consumption.
• These findings highlight the critical impact of early dietary habits on cognitive development and metabolic health.