Dr Sanjay Manohar University of Cambridge 2001 http://www.smanohar.com Motor Systems Dr Sanjay Manohar University of Cambridge 2001 http://www.smanohar.com

Spinal reflex arcs Reflex arc Monosynaptic (spindle) Interneurone Golgi tendon organ (clasp-knife) Ia interneurone Renshaw autoinhibition Antagonist inhibition Polysynaptic (flexor)

Basal ganglia Initiation of action Gating Decision making Caudate Putamen Globus pallidus Substantia nigra Initiation of action Gating SNPR-Eye movement Decision making

Motor hierarchy Posture, stepping, standing Spinal nucleus Reticular formation Vestibular nucleus limb extension Red nucleus limb flexion Cerebellum

Cerebellar pathways

Cerebellar circuits

Cerebellar circuits

Cerebellum Paleocerebellum (vermis) Archicerebellum (tonsil) Spinocerebellum, anterior lobe Spinal c. (Clarke's column) > Fastigial n., red n. Archicerebellum (tonsil) Vestibulocerebellum, flocculonodular lobe Vestibular n. > Emboliform n., Vestibular n. Neocerebellum lateral hemisphere pons, inf. olive > Dentate n., VA/VL, Cx

Marr’s theory

Motor hierarchy Volition Context Cerebellum Striatum Emotion VA VL Association Context Cx 1º Motor Premotor Supplementary CX Cx MA Cerebellum Striatum Emotion VA VL thalamus thalamus

Compare and contrast the roles of cerebral cortex and cerebellum in the control of voluntary movement Combining Decomposition Cx structure, inputs Sequencing Dysdiadochokinesia Rhythm, reciting? Tuning Ataxia, VOR Primary motor Spasticity Cortical reflexes LLR, expectation Association Balint, patient DF (Goodale & Milner 92)

Motor Cortex

SMA vs. PMA Both somatotopic map motor planning SMA PMA