A cerebellar internal model calibrates a feedback controller involved in sensorimotor control

Abstract

Animals must adapt their behavior to survive in a changing environment. Behavioral adaptations can be evoked by two mechanisms: feedback control and internal-model-based control. Feedback controllers can maintain the sensory state of the animal at a desired level under different environmental conditions. In contrast, internal models learn the relationship between the motor output and its sensory consequences and can be used to recalibrate behaviors. Here, we present multiple unpredictable perturbations in visual feedback to larval zebrafish performing the optomotor response and show that they react to these perturbations through a feedback control mechanism. In contrast, if a perturbation is long-lasting, fish adapt their behavior by updating a cerebellum-dependent internal model. We use modelling and functional imaging to show that the neuronal requirements for these mechanisms are met in the larval zebrafish brain. Our results illustrate the role of the cerebellum in encoding internal models and how these can calibrate neuronal circuits involved in reactive behaviors depending on the interactions between animal and environment.

Oligodendrocyte precursor cells sculpt the visual system by regulating axonal remodeling

“…The chamber was then placed onto the stage of a custom-built lightsheet microscope, previously described in ref. 40 . In brief, light from a 473-nm laser (Cobolt) was scanned with galvanometric mirrors (Sigmann Electronik) horizontally to create a ~5-µm-thick excitation sheet.…”

PyZebraScope: an open-source platform for brain-wide neural activity imaging in zebrafish

“…The modular architecture of PyZebrascope further enables advanced microscope control and image processing algorithms. For example, a common issue during whole-brain imaging in zebrafish is the sample's slow drift resulting from gravity force, tail motions of unparalyzed fish 14 , or the pressure of pipette attachment during fictive recording in paralyzed fish 11,13,30 . A small amount of drift, especially in the axial direction along which the volumetric scan is undersampled, can result in the loss of neurons during imaging because the neuronal diameter in the zebrafish brain is usually less than 5 μm.…”

“…We developed PyZebrascope for our custom-built light-sheet microscope (Fig. 1c and S1, Supplementary Table 1 for parts lists), for which many components are common to those in the previous studies 9,11,14,16 . Our system is equipped with two lasers, providing light sources for two excitation arms that are required to scan fish brains from the lateral and front sides (Fig.…”

“…These advantages of DSLM are best exploited in the optically transparent brain of larval zebrafish. DSLM enabled studies of whole-brain neural dynamics during visually-evoked swimmming 11,12 , motor learning 13,14 , learned helplessness 15 , threat escape 16 , and body posture change 17 . Usage of the DSLM also revealed spontaneous noise dynamics across the brain 18 and how those dynamics change during neural perturbations 19,20 or administration of psychoactive reagents 21 .…”

“…For example, light-sheet microscopes for whole-brain imaging in zebrafish (Fig. 1a) typically consist of two excitation optical paths from the lateral and front sides of the fish and one optical detection path above the fish 11,14,16,17 (Fig. 1b).…”