Invertebrates as models of learning and memory: investigating neural and molecular mechanisms

In this Commentary, we shed light on the use of invertebrates as model organisms for understanding the causal and conserved mechanisms of learning and memory. We provide a condensed chronicle of the contribution offered by mollusks to the studies on how and where the nervous system encodes and stores memory and describe the rich cognitive capabilities of some insect species, including attention and concept learning. We also discuss the use of planarians for investigating the dynamics ofmemory during brain regeneration and highlight the role of stressful stimuli in forming memories. Furthermore, we focus on the increasing evidence that invertebrates display some forms of emotions, which provides new opportunities for unveiling the neural and molecular mechanisms underlying the complex interaction between stress, emotions and cognition. In doing so, we highlight experimental challenges and suggest future directions that we expect the field to take in the coming years, particularly regarding what we, as humans, need to know for preventing and/or delaying memory loss.

Automated summary

This Commentary discusses the use of invertebrates as model organisms for studying learning and memory mechanisms. It provides a brief overview of the contributions made by mollusks in understanding memory encoding and storage in the nervous system, and describes the cognitive abilities of certain insect species. The article also explores the use of planarians in studying memory dynamics during brain regeneration, and highlights the role of stressful stimuli in memory formation. Additionally, it focuses on the emerging evidence of invertebrates displaying emotions and the opportunity it presents for studying the interaction between stress, emotions, and cognition at a neural and molecular level.