Studying Evolution of Nervous Systems Through Behavioral and Whole-Body Neural Imaging of Hydra vulgaris

Abstract

Cnidarians represent early branches in the animal kingdom with simple, non-centralized nervous systems. Studying how these animals utilize their nervous systems is fundamental for understanding the evolution of nervous systems. Recent advancements in genetic and imaging technologies such as whole-body neuronal imaging enabled this line of research using Hydra vulgaris, along with other cnidarians. This review explores how Hydra’s nervous systems respond to environmental stimuli and orchestrate complex motor behaviors, revealing preferential sensing and conserved circuit mechanisms. Looking forward, this review addresses open questions and technologies needed in this field.