Roles of Inhibition in Shaping Sensory Representations in the Cerebellar Input Layer

Hull, Court A

Fleming, Elizabeth

2022-02-11T21:38:29Z

2021

Neurobiology

The cerebellum plays a central role in motor learning by establishing sensorimotor associations necessary for coordinated movement. To do so, the cerebellum’s input layer, the granule cell layer, has been proposed to integrate and transform sensorimotor input in a way that creates unique population ensembles that can be easily learned by downstream Purkinje cells. For my thesis work, I used calcium indicators in combination with a specific pharmacological block of inhibition to measure single and combined sensory responses in granule cells in awake, behaving mice to test if local synaptic inhibition sparsens and diversifies granule cell ensembles. I have also tested if this feature can be a component of cerebellar learning, and whether neuromodulation can influence inhibition in a manner consistent with regulating sensorimotor representations. I have found that local synaptic inhibition sparsens and thresholds sensory responses, as well as sculpts population responses by establishing intensity preferences and selectively suppressing inputs. I have also found that inhibition to granule cells is necessary for performance of a cerebellum-dependent sensorimotor task. Additionally, serotonin modulates inhibition to suppress granule cell output, suggesting that it could enable learning flexibility to accommodate changes in environment or internal states. Together, my data suggest that synaptic inhibition has an important role in forming sensorimotor associations in the cerebellum.

https://hdl.handle.net/10161/24363

Neurosciences

Roles of Inhibition in Shaping Sensory Representations in the Cerebellar Input Layer

Dissertation

23.17808219178082

2024-01-18T00:00:00Z