Cerebellum Flashcards
define coordination problem
motor deficits without weakness or sensory deficit
4 illnesses associated with diminished cerebellar function
fetal alcohol syndrome, autism, schizophrenia, tuberous sclerosis
how many layers in cerebellar cortex?
3 (molecular, purkinje, granule)
name the 3 cerebellar lobes, and how many lobules in each
anterior (5), posterior (4), flocculonodular (1)
how many major cell types in cerebellar cortex? name them.
5: granule (only excitatory) golgi stellate purkinje basket
(mnemonic: go grab sue’s picnic basket!)
describe spatial organization of cerebellar cortex
mostly right angles and parallel lines
2 inputs to cerebellar cortex:
mossy fibers olivocerebellar system (climbing fibers)
only output from cerebellar cortex:
purkinje cell axons. and it’s inhibitory, GABAergic, surprisingly
all synaptic input to granule cells occur where?
at the “claw” at the end of each dendrite.
all parallel fibers are…
…axons of the granule cells
where do the 2 inputs to cerebellar cortex each originate?
olivocerebellar/climbing fibers: inferior olive
mossy fibers: SC/medulla/pons/midbrain
damage to cerebellum can cause
decomposition of movement, delayed onset and “brake” of movement, hypermetria (moving too far), intention tremor, deficits in time perception
3 deep cerebellar nuclei and their locations
- fastigial (most medial)
- interpositus (emboliform and globose, in between)
- dentate (most lateral)
where are basket and stellate cells located?
molecular layer
purkinje cell morphology
large soma with a giant pancake dendritic arbor. has 2 functional compartments, the proximal dendrites and the distal spiny branchlets
where do purkinje cell proximal dendrites get their inputs from?
climbing fibers from the olives in a 1:1 ratio
where do purkinje cell distal dendrites, aka spiny branchlets, get their inputs from?
the parallel fibers of 10’s of 1000’s of different granule cells
what is the output of basket cells?
feed-forward inhibition of purkinje cells, their axons form “baskets” around the soma
what is the output of golgi cells?
inhibition of granule cells, both feed-forward (onto their axons aka parallel fibers) and feed-back (onto mossy fiber axons that will then synapse with granule cells)
rosette
the en passant structure on mossy fiber axons formed by terminals interlocking with the claws on granule cell dendrites and golgi cells
where does excitatory output of the cerebellar nuclei go?
pontine nuclei
where does inhibitory output of the cerebellar nuclei go?
inferior olive
what is a module?
functional unit in cerebellum, runs longitudinally/perpendicular to long axis of the folia), distinguishable with myeloarchitectonics, has different electrophysiological properties than its neighbors
