Can Green Tea Alleviate the Effects of Stress Related to Learning and Long-Term Memory in the Great Pond Snail (Lymnaea stagnalis)?

Abstract

Stress and anxiety have become more prevalent issues in recent years and teenagers are especially at high risk. Recent studies show that experiencing stress while learning can impair brain-cell communication, thus inhibiting learning. Green tea is believed to have the opposite effect, aiding in learning and memory retention. Lymnaea stagnalis is a pond snail with a simple nervous system and easily observable behaviors, making it an excellent model organism for human neurobiology. In this study, we used L. stagnalis to explore the relationship between green tea and a stressor that impairs memory formation to determine the effects of both green tea and stress on the snails’ ability to learn, form, and retain memories. Memory was assessed using a conditioning procedure known as conditioned taste aversion (CTA), where snails are exposed to a sweet substance followed by a bitter taste with the number of biting responses being recorded. For the CTA groups, a total of 33 snails in 3 separate cohorts (Control (i.e. no stress), stressed, and stressed with green tea) was used in the trainings. Our results indicated that the best learning and memory occurred in the combination stressed with green tea group, specifically for long-term memory, although snails displayed good learning and memory during the short-term and intermediate trials. Stress was shown to be harmful to snail learning and memory for short-term, intermediate, and long-term memory. Thus, green tea not only alleviated the effects of stress, but also improved the snails’ ability to learn and remember compared to their control counterparts (not stressed) group.