Neuroanatomy of the Cetacean Sensory Systems

Simple Summary Cetaceans, which include dolphins, porpoises, and whales, show astounding and distinctly specialised adaptations of their senses that allow them to thrive in the aquatic environment. They possess the abilities to echolocate, are likely to discern bioelectric fields, sense water currents, and perform various other sensory tasks, amidst shifting and challenging environmental circumstances. For many of their senses, we still lack a basic understanding of their underlying physiology. In this review, we provide a summary of the neuroanatomical knowledge of cetacean sensory systems to date. We describe the peripheral sensory cells in organs like the eye, ear, and skin, and trace the nervous pathways up to the brain where the signals are processed in dedicated areas. We highlight recent advances and knowledge gaps that exist at the various anatomical levels, accentuating the pressing need for further research to bridge these knowledge gaps.Abstract Cetaceans have undergone profound sensory adaptations in response to their aquatic environment during evolution. These adaptations are characterised by anatomo-functional changes in the classically defined sensory systems, shaping their neuroanatomy accordingly. This review offers a concise and up-to-date overview of our current understanding of the neuroanatomy associated with cetacean sensory systems. It encompasses a wide spectrum, ranging from the peripheral sensory cells responsible for detecting environmental cues, to the intricate structures within the central nervous system that process and interpret sensory information. Despite considerable progress in this field, numerous knowledge gaps persist, impeding a comprehensive and integrated understanding of their sensory adaptations, and through them, of their sensory perspective. By synthesising recent advances in neuroanatomical research, this review aims to shed light on the intricate sensory alterations that differentiate cetaceans from other mammals and allow them to thrive in the marine environment. Furthermore, it highlights pertinent knowledge gaps and invites future investigations to deepen our understanding of the complex processes in cetacean sensory ecology and anatomy, physiology and pathology in the scope of conservation biology.