Functional Development of the Vestibular System

2019

eLife

102

Mature locomotion requires that animal nervous systems coordinate distinct groups of muscles. The pressures that guide the development of coordination are not well understood. To understand how and why coordination might emerge, we measured the kinematics of spontaneous vertical locomotion across early development in zebrafish (Danio rerio) . We found that zebrafish used their pectoral fins and bodies synergistically during upwards swims. As larvae developed, they changed the way they coordinated fin and body movements, allowing them to climb with increasingly stable postures. This fin-body synergy was absent in vestibular mutants, suggesting sensed imbalance promotes coordinated movements. Similarly, synergies were systematically altered following cerebellar lesions, identifying a neural substrate regulating fin-body coordination. Together these findings link the vestibular sense to the maturation of coordinated locomotion. Developing zebrafish improve postural stability by changing fin-body coordination. We therefore propose that the development of coordinated locomotion is regulated by vestibular sensation.

Section: Discussionmentioning

confidence: 95%

A primal role for the vestibular sense in the development of coordinated locomotion

Ehrlich

2019

eLife

102

“…Second, zebrafish are genetically accessible, with established mutant lines that disrupt balance and posture (Nicolson et al, 1998). Third, the external development of zebrafish embryos permits continuous access, whereas in amniotes much of the development takes place in ovo or in utero (Curthoys, 1979; Peusner, 2001; Fritzsch et al, 2014; Beraneck et al, 2014). Finally, the mostly transparent bodies of zebrafish larvae permit anatomical, electrophysiological, and optical (Favre-Bulle et al, 2017; Vanwalleghem et al, 2018) approaches during external development.…”

Section: Introductionmentioning

confidence: 99%

Development of vestibular behaviors in zebrafish

Bagnall

Current Opinion in Neurobiology

2018

Most animals orient their bodies with respect to gravity to facilitate locomotion and perception. The neural circuits responsible for these orienting movements have long served as a model to address fundamental questions in systems neuroscience. Though postural control is vital, we know little about development of either balance reflexes or the neural circuitry that produces them. Recent work in a genetically and optically accessible vertebrate, the larval zebrafish, has begun to reveal the mechanisms by which such vestibular behaviors and circuits come to function. Here we highlight recent work that leverages the particular advantages of the larval zebrafish to illuminate mechanisms of postural development, the role of sensation for balance circuit development, and the organization of developing vestibular circuits. Further, we frame open questions regarding the developmental mechanisms for functional circuit assembly and maturation where studying the zebrafish vestibular system is likely to open new frontiers.

“…Therefore, development does not require unlocking or composing new actions, but instead involves selecting a particular combination of equally functional innate actions [2, 77]. As in other vertebrates [78], the capacity of the vestibular system to stabilize gaze [60] and posture [16] improves markedly with age. In mature animals, vestibular information is thought to be weighted by reliability for perceptual computations [79], consistent with learning rules [80] that may underlie locomotor development.…”

Section: Discussionmentioning

confidence: 99%

A primal role for balance in the development of coordinated locomotion

Ehrlich

2019

Preprint

Mature locomotion requires that animal nervous systems coordinate distinct groups of muscles. The pressures that guide the development of coordination are not well understood. We studied vertical locomotion in developing zebrafish to understand how and why coordination might emerge. We found that zebrafish used their pectoral fins and bodies synergistically to climb. As they developed, zebrafish came to coordinate their fins and bodies to climb with increasing postural stability. Fin-body synergies were absent in mutants without vestibular sensation, linking balance and coordination. Similarly, synergies were systematically altered following cerebellar lesions, identifying a neural substrate regulating fin-body coordination. Computational modeling illustrated how coordinated climbing could improve balance as zebrafish mature. Together these findings link the sense of balance to the maturation of coordinated locomotion. As they develop, zebrafish improve postural stability by optimizing fin-body coordination. We therefore propose that the need to balance drives the development of coordinated locomotion.