Translation information processing is regulated by protein kinase C-dependent mechanism in Purkinje cells in murine posterior vermis.

The cerebellar posterior vermis generates an estimation of our motion (translation) and orientation (tilt) in space using cues originating from semicircular canals and otolith organs. Theoretical work has laid out the basic computations necessary for this signal transformation, but details on the cellular loci and mechanisms responsible are lacking. Using a multicomponent modeling approach, we show that canal and otolith information are spatially and temporally matched in mouse posterior vermis Purkinje cells and that Purkinje cell responses combine translation and tilt information.

The Macaque Cerebellar Flocculus Outputs a Forward Model of Eye Movement.

The central nervous system (CNS) achieves fine motor control by generating predictions of the consequences of the motor command, often called forward models of the movement. These predictions are used centrally to detect not-self generated sensations, to modify ongoing movements, and to induce motor learning. However, finding a neuronal correlate of forward models has proven difficult.

Searching for an Internal Representation of Stimulus Kinematics in the Response of Ventral Paraflocculus Purkinje Cells.

Motor control theories propose that the central nervous system builds internal representations of the motion of both our body and external objects. These representations, called forward models, are essential for accurate motor control. For instance, to produce a precise reaching movement to catch a flying ball, the central nervous system must build predictions of the current and future states of both the arm and the ball.

GABA-A Inhibition Shapes the Spatial and Temporal Response Properties of Purkinje Cells in the Macaque Cerebellum.

Data from in vitro and anesthetized preparations indicate that inhibition plays a major role in cerebellar cortex function. We investigated the role of GABA-A inhibition in the macaque cerebellar ventral-paraflocculus while animals performed oculomotor behaviors that are known to engage the circuit. We recorded Purkinje cell responses to these behaviors with and without application of gabazine, a GABA-A receptor antagonist, near the recorded neuron.

Spatiotemporal properties of optic flow and vestibular tuning in the cerebellar nodulus and uvula.

Convergence of visual motion and vestibular information is essential for accurate spatial navigation. Such multisensory integration has been shown in cortex, e.g.

Computation of egomotion in the macaque cerebellar vermis.

The nodulus and uvula (lobules X and IX of the vermis) receive mossy fibers from both vestibular afferents and vestibular nuclei neurons and are thought to play a role in spatial orientation. Their properties relate to a sensory ambiguity of the vestibular periphery: otolith afferents respond identically to translational (inertial) accelerations and changes in orientation relative to gravity. Based on theoretical and behavioral evidence, this sensory ambiguity is resolved using rotational cues from the semicircular canals.

How vestibular neurons solve the tilt/translation ambiguity. Comparison of brainstem, cerebellum, and thalamus.

The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinations of tilt and translation.

Response clustering in transient stochastic synchronization and desynchronization of coupled neuronal bursters.

We studied the transient dynamics of synchronized coupled neuronal bursters subjected to repeatedly applied stimuli, using a hybrid neuroelectronic system of paddlefish electroreceptors. We show experimentally that the system characteristically undergoes poststimulus transients, in which the relative phases of the oscillators may be grouped in several clusters, traversing alternate phase trajectories. These signature transient dynamics can be detected and characterized quantitatively using specific statistical measures based on a stochastic approach to transient oscillator responses.

Noise-induced transition to bursting in responses of paddlefish electroreceptor afferents.

The response properties of ampullary electroreceptors of paddlefish, Polyodon spathula, were studied in vivo, as single-unit afferent responses to external electrical stimulation with varied intensities of several types of noise waveforms, all Gaussian and zero-mean. They included broadband white noise, Ornstein-Uhlenbeck noise, low- or high-frequency band-limited noise, or natural noise recorded from swarms of Daphnia zooplankton prey, or from individual prey. Normally the afferents fire spontaneously in a tonic manner, which is actually quasiperiodic due to embedded oscillators.

Purkinje cells in posterior cerebellar vermis encode motion in an inertial reference frame.

The ability to orient and navigate through the terrestrial environment represents a computational challenge common to all vertebrates. It arises because motion sensors in the inner ear, the otolith organs, and the semicircular canals transduce self-motion in an egocentric reference frame. As a result, vestibular afferent information reaching the brain is inappropriate for coding our own motion and orientation relative to the outside world.