No food for thought: an intermediate level of food deprivation enhances memory in Lymnaea stagnalis

Nutritional status plays an important role in cognitive functioning, but there is disagreement on the role that food deprivation plays in learning and memory. In this study, we investigated the behavioral and transcriptional effects induced by different lengths of food deprivation: 1 day, which is a short time period of food deprivation, and 3 days, which is an 'intermediate' level of food deprivation. Snails were subjected to different feeding regimens and then trained for operant conditioning of aerial respiration, where they received a single 0.5 h training session followed by a long-term memory (LTM) test 24 h later. Immediately after the memory test, snails were killed and the expression levels of key genes for neuroplasticity, energy balance and stress response were measured in the central ring ganglia. We found that 1 day of food deprivation was not sufficient to enhance snails' LTM formation and subsequently did not result in any significant transcriptional effects. However, 3 days of food deprivation resulted in enhanced LTM formation and caused the upregulation of neuroplasticity and stress-related genes and the downregulation of serotonin-related genes. These data provide further insight into how nutritional status and related molecular mechanisms impact cognitive

Automated summary

Nutritional status plays a crucial role in cognitive functioning, with disagreements on the impact of food deprivation on learning and memory. This study examined the effects of different lengths of food deprivation on behavior and gene expression. Results showed that 1 day of deprivation had no significant effects, while 3 days of deprivation enhanced long-term memory formation and influenced the expression of neuroplasticity, stress, and serotonin-related genes. These findings provide insights into the relationship between nutrition, molecular mechanisms, and cognitive function.