Vestibular physiology and function in zebrafish

Abstract

The vestibular system of the inner ear provides information about head motion and spatial orientation relative to gravity to ensure gaze stability, balance, and postural control. Zebrafish, like humans, have five sensory patches per ear that serve as peripheral vestibular organs, with the addition of the lagena and macula neglecta. The zebrafish inner ear can be easily studied due to its accessible location, the transparent tissue of larval fish, and the early development of vestibular behaviors. Thus, zebrafish are an excellent model for studying the development, physiology, and function of the vestibular system. Recent work has made great strides to elucidate vestibular neural circuitry in fish, tracing sensory transmission from receptors in the periphery to central computational circuits driving vestibular reflexes. Here we highlight recent work that illuminates the functional organization of vestibular sensory epithelia, innervating first-order afferent neurons, and second-order neuronal targets in the hindbrain. Using a combination of genetic, anatomical, electrophysiological, and optical techniques, these studies have probed the roles of vestibular sensory signals in fish gaze, postural, and swimming behaviors. We discuss remaining questions in vestibular development and organization that are tractable in the zebrafish model.

Neural connections of the torus semicircularis in the adult Zebrafish

“…Its high degree of gene homology and similarity of developmental processes with other model vertebrates, small size, and short reproductive cycle make them advantageous species for detailed studies on the organization and development of its nervous system during embryonic and larval life. For example, the zebrafish lateral line is a model for study of the establishment of neuromast hair cell polarity and their selective connections with the hindbrain, as well as for the development of the inner ear system (reviews in: Ghysen & Dambly‐Chaudière, 2007; Thomas et al., 2015; Alsina & Whitfield, 2017; Baeza‐Loya & Raible, 2023). Thus, it is of paramount importance to investigate the organization of the central octavolateralis systems also in the adult life.…”

Differential expression of mechanotransduction complex genes in auditory/vestibular hair cells in zebrafish

“…Here we characterize the expression pattern of the tmc1/2 orthologues in the zebrafish inner ear during development. The fish inner ear resembles the labyrinth in other species, with five sensory or “end” organs: the macular end organs of the utricle and saccule along with three cristae in the semicircular canals ( Baeza-Loya and Raible, 2023 ). In contrast to mammals, hair cells within the maculae mature quite rapidly in zebrafish.…”