Adaptive Balance in the Posterior Cerebellum

The study explored how the posterior cerebellum, specifically vermal lobules IX-X and hemisphere lobule X, played a role in maintaining balance through vestibular and optokinetic adaptation. It was found that these regions encoded gravity, head movement, and self-motion using various sensory inputs, which were crucial for balance during self-induced motion. The study highlighted the role of cerebellar climbing and mossy fibers in exciting Purkinje cells, with climbing fibers also decreasing their discharge via stellate cell inhibitory interneurons. Behavioral adaptations were observed as reflexive eye movements persisting after prolonged vestibular or optokinetic stimulation. At the cellular level, the transcription of corticotropin releasing factor (CRF) and microRNAs in response to optokinetic stimulation was noted, potentially influencing GABAA receptor regulation. Additionally, neurosteroids like estradiol and dihydrotestosterone were found to affect vestibular neuron adaptation. The review discussed how these adaptive changes in cerebellar and vestibular systems contributed to balance control.