The vestibular system in the inner ear plays a central role in sensorimotor control by informing the brain about the orientation and linear acceleration of the head. In the present work we studied the zebrafish larva response to different vestibular stimulus, to characterize the vestibulospinal reflexes and the underlying neural substrates. In the first part of the thesis we described the tail movements elicited by vestibular stimulation, finding that larvae use their tail to compensate imbalance. Next, we characterized different neural populations that are active during sinusoidal-roll stimulation. Despite the fact that vestibular cues are central for locomotion and postural control, most neurophysiological experiments are performed using head-fixed configurations depriving animals of vestibular inputs. To overcome this limitation, we decorated the utricular otolith of the vestibular system with paramagnetic nanoparticles. This procedure effectively endowed the animal with magneto-sensitive capacities: applied magnetic field gradients induced forces on the otoliths resulting in robust behavioral responses comparable to that evoked by rotating the animal by up to 20°. We recorded the whole-brain neuronal response to this fictive vestibular stimulation using light-sheet functional imaging. Experiments performed in unilaterally injected fish revealed the activation of a commissural inhibition between the brain hemispheres. This magnetic-based stimulation technique opens new perspectives to functionally dissect the neural circuits underlying vestibular processing and to develop multisensory virtual environments including vestibular feedback.