Cerebellar Function Flashcards
What are the 3 lobes of the cerebellum
anterior, posterior flocculonodular
vermis
center of cerebellum
cerebellar lesions cause symptoms on what side
ipsilateral
mossy fibers come from
from neurons in the spinal cord and brainstem
climbing fibers come from
from inferior olives
what do climbing fibers contract
Purkinje cells
What is the input to cerebellar cortex
mossy fibers
climbing fibers
nonlaminar afferents
What are the 5 main types of neurons in the cerebellar cortex
purkinje granule golgi stellate basket
purkinje cells
only cell to project out of cerebellar cortex
granule cell
excitatory cell in cerebellar cortex
origin of parallel fibers
golgi celsl
affect dendritic input to purkinje cells by inhibting granule cells
stellate cells
affect dendritic integration of purkinje cells through inhibitory synpases on dendritic tree
basket cells
make inhibitory synpases near intitiral segment of purkinje cell axon
how many climbing fibers does purkinje cell recieve
1
1 AP in climbing fibers is enough to result in what
complex Ca dependent spike in purkinje cell
what does mossy fiber input result in
smaller EPSPs that have to sum up to result in a single AP
how are purkinje fibers involved in motor learning
climbing fiber input causes changes in Purkinje cell future response to mossy fiber input
output of purkinje cells from cerebellar cortex is usually
inhibitory
output of deep cerebellar nuclei from cerebellar cortex is usually
excitatory
anatomical region of vestibulcerebellum
floccular-nodular lobe
input to vestibulocerebellum
primary afferent from vestibular labyrinth and fibers from vestibular nuclei
indirect visual input from superior colliuli and striate cortex
functions of vestibulocerebellum
regulate equilibrium gait posture, coordinate movements of head and eyes
lesion to vestibulocerebellum cause what
ataxic gait, eye movement problems
lesion to vestibulo cerebellum causes patient to fall tow hat side
toward the side of lesion
anatomical region of spinocerebellum - vermis portion
anterior and posterior portions of the vermis
somatosensory input to spinocerebellum- vermis protion
spinal cord from axial and proximal body parts
vestibular inputs to spinocerebellum - vermis protion
facial, visual, and auditory input to posterior lobe only
output from spinocerebellum - vermis protion
via fastigial nucleis to medial motor systems, vestibular nucleus and reticular formation, morot cortex
main function of spinocerebellum - vermis protion
regulate axial and proximal musculature, control of saccades, smooth pursuit eye movements
anatomical region of spinocerebellum - intermediate part of hemisphere - paravermal region
intermediate part of hemisphere
input to spinocerebellum - intermediate part o fhemisphere = paravermal region
distal body part sensory info
primary motor and somatic sensory cortex
function of spinocerebellum - intermeidate part of hemisphere - paravermal region
regulate distal muscles, concerned with ongoing motor execution and regulation of muscle tone
lesions to spinocerebellum intermeidate part of hemisphere - paravermal region causes deficits where
ipsilateral
what type of mechanisms does spinocerebellum use to regulate ongoing movements
feedback and feedforward
where is cerebrocerebellum or pontocerebellum located
lateral part of hemisphere
input to cerebrocerebellum (pontocerebellum)
cortical afferents via pontine nuclei
output from cerebrocerebellum (pontocerebellum)
via dentate nucleus to red nucleus and the thalamus which projects to the premotor and primary motor cortex and prefrontal cortesx
function of cerebrocerebellum (pontocerebellum)
preparation for movement
lesion in cerebrocerebellum (pontocereellum) causes what
delays in initiating and terminating movements
problem in multi-joint movement
ability to judge elapsed time in non-motor tasks
how was motor performance in pt with cerebellar deficits with closed eyes
improved
hypermetria
overreaching the intended goal
hypometria
undershoot the traget
dysarthria
disorder in articulating speech
titubation
tremor of entire trunk of head during stance and gait. caused by cerebellar midline lesions
how can vestibular-ocular reflex be suppresed
visual fixation
pendular muscle stretch reflexes
pendular knee jerk response to tap on patellar tendon
synergy
movements are coordinated over 2 or more joints to make a smooth movement
rebound phenomena
inability agonist and anatgonist to adapt to rapid changes in load
alcoholism can cause atrophy where
anterior love of cerebellum
atrophy of anterior lobe of cerebellum causes
difficulty walking and with leg control in general. control of arms and head less affected
friereich ataxia
recessive inherited progressive spinocerebellar ataxia
triplet repeats
high fidelity tracts
carry information for unconscious proprioception from receptors in the muscles, tendons, joints
internal feedback tracts
monitor the activity of spinal interneurons and of descending motor signals from cerebral cortex and brainstem
reading aloud results in increased activity where
right lateral cerebellum
does the cerebellum have more input or output
input
how are the cerebellar cortex and motor cortex connected
contralaterally
what are granule cells excited by
mossy fibers
