Abstract

This week’s journal club will discuss the most densely (neuronally) populated area of the brain – the cerebellum, a region that (notably) uses about 60% of all the brain’s neurons for dimensionality expansion. In the first part of the talk, we will give a basic introduction to the physiology and function of the cerebellum as a whole. We will cover the traditionally recognised role of the cerebellum in motor coordination and learning, discussing the Marr-Albus model of motor learning and illustrating several limitations and extensions of the original model, including the role of climbing fibres as error signals. Finally, we will cover some of the less well known role of the cerebellum in nonmotor domains such as cognition, pain, memory, and sleep.

In the second part of the talk, we will look at a more recent paper where Fakharian and colleagues presents on how computation in the cerebellum can be predicted by the null space theory, which states that neurons spike not just to drive movement but also to cancel unwanted effects of other neurons. In marmosets, each Purkinje cell’s spike moves the eyes along a vector. When multiple cells spike, perpendicular contributions cancel, keeping the population aligned with the intended movement. Mossy fibers provide motor commands and goals, while interneurons transform these signals so Purkinje cells predict when the movement has reached its target. Overall, the cerebellum computes by both generating and suppressing neural activity to ensure precise motor control.

1. https://www-annualreviews-org.ezp.lib.cam.ac.uk/content/journals/10.1146/annurev-neuro-100423-104943
2. https://www-sciencedirect-com.ezp.lib.cam.ac.uk/science/article/pii/S0306452220303961?
3. https://www.science.org/doi/10.1126/science.adu6331
4. https://www.science.org/doi/10.1126/science.adx8989