The cerebellum with its layered structure and stereotyped and conserved connectivity has long puzzled neurobiologists. While it is well established that the cerebellum functions in regulating balance, motor coordination and motor learning, how it achieves these end results has not been very clear. Recent technical advances have made it possible to tease apart the contributions of cerebellar cell types to movement in behaving animals. We review these studies focusing on the three major cerebellar cell types, namely: granule cells, Purkinje neurons and the cells of the deep cerebellar nuclei. Further, we also review our current understanding of cortico-cerebellar and basal ganglia-cerebellar interactions that play vital roles in motor planning and motor learning.

Here we experimentally map the dynamics of electron plasma waves in laser solid interaction.We do time resolved measurements of second harmonic and hard X-ray generation from interaction of intense (10 16 W cm −2 , 100 fs, 800nm) laser with a pre-plasma generated on a solid surface. The parameter space explored in this time resolved study includes variation of scale length, laser polarization and laser intensity in conjunction. These measurements done together brings novel features of strongly driven electron plasma wave behavior, which have not been explored experimentally so far. We model the results in terms of Resonance Absorption and Wave-Breaking mechanisms.The Harmonic and X-ray emission show contrasting behaviour, which indicates pitfalls in trying to increase harmonic efficiencies by brute force. However by simple adjustments, we observe that hard X-rays can be enhanced or controlled upto two orders of magnitude and second harmonic upto one order of magnitude under optimum conditions. These results should help us understand the governing mechanisms for short wavelength generation and fast particle generation to develop more efficient sources for application purposes.

The brain uses internal models to estimate future states of the environment based on current inputs and to predict consequences of planned actions. Neural mechanisms that underlie the acquisition and use of these predictive models are poorly understood. Using a novel experimental paradigm, we show clear evidence for predictive processing in the larval zebrafish brain. We find that when presented with repetitive optic flow stimuli, larval zebrafish modulate their optomotor response by quickly acquiring internal representations of the optic flow pattern. Distinct subcircuits in the cerebellum are involved in the predictive representation of stimulus timing and in using them for motor planning. Evidence for such predictive internal representations appears quickly within two trials, lasts over minute timescales even after optic flow is stopped and quickly adapts to changes in the pattern. These results point to an entrainment-based mechanism that allows the cerebellum to rapidly generate predictive neural signals ultimately leading to faster response times.