The Effect of Temperature-Induced Stress at Different Developmental Periods on Short-Term Memory of C. elegans

Abstract

As the incidence of neurodegenerative diseases continues to increase, it is essential to evaluate the causal factors that lead to neurodegeneration and resultant memory loss. In this study, Caenorhabditis elegans were used as a model organism to explore the effects of developmental stress on learning and short-term memory. Half of the population were placed into elevated temperatures, to invoke heat stress, while the other half was kept at their optimal functioning temperature of 22°C. The worms were then taught a simple chemosensory learning task. Results show that 25°C produced a small reduction in learning, while 28°C produced a substantial reduction. In a follow-up study, C. elegans were exposed to 28°C at different life stages Day 0 (embryo), Day 1, Day 2, and Day 3 stress each reduced learning when compared to controls, with the greatest deficit being stress experienced during Day 2. Insights into neurodevelopmental time periods of vulnerability to stress and the potential mechanisms affected by early-life stress can help in the prevention of neurodegenerative diseases and their associated cognitive decline.