cerebellum Flashcards
cerebellar fun facts
little brain latin , more than half neurons here, regular cytoarchitecture throughout/animals, ongoing motion and thoughts
overview of cerebellar circuit
upper motor in M1 sends signal to contra cerebellar hemisphere, as well as to lower motor
cerebellar recieves ipsi feedback from proprioception
compares signals, feedback to M1
cerebellar anaotmy
arbor vitae white matter
highly folded gray matter
3 subdivisions of cerebellum
folcculonodular lobe, anterior lobe, posterior lobe
flocculonodular lobe functons
“vestibulocerebellum”
balance/eye movements, input from vestublar nuclei and output to fastigial nucli and vestibular nuceli, then to LMN
anterior lobe
spincocerebellum, error and movement coord and motor execution
input from proprioception and output to interposed nuclei and descending motor paths
posterior lobe
cerebrocerebellum/neocerebellum
input from cortex (motor plan)
output to dentate nucleus/thalamus/cortex
3 deep nuclei
fastigial = output of vestibulo (vermis, most medial), send to motor execution paths (descending/extrapyramidal)
interposed = output of spino, send to motor execution paths (descending/extrapyramidal)
dentate = output of cerebro (most lateral), send to motor cortices for motor planning
3 peduncles
superior = efferent to cortex (error feedback)
middle = afferent, input from cortex/pons (copy of command)
inferior = a/efferent about body position, send to floc. lobe (proprioception)
3 layers of cerebellum
molecular = axons/inter
purkinje = single cell row
granular = densely packed granule cells and interneurons
3 neuron types
granule cells = form parallel fibers
purkinje cells = project to deep nuclei (dentate/inter/fast)
inhibitory neurons = basket/stellate/golgi
2 types of input
both are excitatory onto purkinje
climbing fibers from inf. olive
mossy fibers from spinal cord/cortex via pons
mossy input to granule cells about voluntary movements
cerebellar plasticity
when a climbing fiber synapses with a parallel fiber, parallel is weakened
parallel synapses onto purkinje
Marr-Albus-Ito motor learning theory = granule cells (parallel) give continuous info about body, when error, climbing fires which turn off parallel (inf. olive does error)
cerebellar damage
balance, nystagmus, wide gait, land and mood too