Producing adapted movements Sensorimotor functions of the cerebellum

Producing adapted movements Sensorimotor functions of the cerebellum EXCI-355 Neural Control of Human Movement

Plan l l Cerebellar structures Connectivity Movement implications Pathology

Textbooks l Neuroscience, Purves et al. l Principles of Neural Science, Kandel et al.

Functions of the cerebellum l Motor correction: adjusting movement on the fly based on sensory and proprioceptive input l Motor learning: Improving performance of motor sequences with repetition l Balance, coordinating muscle systems across the body

Figure 19. 1 Overall organization and subdivisions of the cerebellum (Part 1)

Know your cerebellum!

Figure 19. 1 Ventral organization and subdivisions of the cerebellum (Part 2)

Figure 19. 1 Overall organization and subdivisions of the cerebellum (Part 3)

Figure 19. 2 Brainstem and diencephalon components related to the cerebellum ain Pontine nuclei – cortical input Inferior olive – movement error/correction Cuneate & Clarke – proprioceptive input br mid s pon lla du me

Figure 19. 3 Functional organization of the inputs to the cerebellum (Part 1)

Ascending vs. descending connectivity Descending input Cortex Ascending projections Cerebellum Ascending input Descending projections Brainstem

Summary of inputs to the cerebellum l Descending (from cortex) l l Motor cortex: Movement commands Premotor cortex: Planning/selecting movement Relayed via pontine and red nuclei Ascending input (sensory information) l l Proprioceptive information Vestibular information

Figure 19. 3 Functional organization of the inputs to the cerebellum (Part 2)

Regions of the cerebral cortex that project to the cerebellum P F T O Cortical inputs: premotor and motor areas in the frontal cortex, and sensory areas in the parietal cortex

Figure 19. 1 Functional organization of cerebellar hemispheres l Cerebrocerebellum: Motor planning and coordination l Spinocerebellum: Control of ongoing body and limb movements l Vestibulocerebellum: Posture, balance, eye movements

Figure 19. 4 Somatotopic maps of the body surface in the cerebellum l Sensory inputs remain topographically mapped l Nearby cerebellar areas control adjacent body parts

Figure 19. 5 Functional organization of cerebellar outputs

Figure 19. 6 Functional organization of the major ascending outputs from the cerebellum (Part 1) l Outputs of deep cerebellar nuclei: l l l Exit the cerebellum through the superior cerebellar peduncle Project direct to subcortical targets Through the thalamus to motor cortex

Figure 19. 6 Functional organization of the major ascending outputs from the cerebellum (Part 2)

Figure 19. 8 Functional organization of the major descending outputs from the cerebellum

Summary of efferent projections from the cerebellum l Ascending: l l Back to motor and premotor cortex Descending: l l l Superior colliculus: eye movements Reticular formation: planning/correcting movement Vestibular nuclei: balance

Activity l l The cerebellum cares about the opposite side of the body _____ The cerebellum gets information from the spinal cord _____ The cerebellum gets information from the cerebral cortex _____ The cerebellum is organized of a cortex part and a nuclear part _____

Activity l l The cerebellum cares about the opposite side of the body __F___ The cerebellum gets information from the spinal cord __T___ The cerebellum gets information from the cerebral cortex __T___ The cerebellum is organized of a cortex part and a nuclear part __T___

Figure 19. 14 The pathology of neurological diseases provides insights into the function of the cerebellum What part of cerebellum is damaged?

Figure 19. 1 Overall organization and subdivisions of the cerebellum (Part 1)

How might this damage give rise to the deficit seen? l http: //www. youtube. com/watch? v=0 j. Yae. Rz. Y F 94

Figure 19. 4 Somatotopic maps of the body surface in the cerebellum l Sensory inputs remain topographically mapped l Nearby cerebellar areas control adjacent body parts

Which part of cerebellum do you think is affected? l http: //www. youtube. com/watch? v=5 e. Bwn 22 B nio l Which hemisphere is lesioned?

Conclusions l l l The cerebellum helps in motor coordination by parallel computations Is involved in motor planning and execution Damage to the cerebellum: l l Causes ipsilateral deficits Interferes with smooth, coordinate movement