Lecture 9: Cerebellum Flashcards
what is the cerebellum?
associative learning machine.
what is the cerebellum in control of?
control of posture, fine movement, motor learning and balance.
what functions may the cerebellum have?
cognitive and emotional
what sections can the cerebellum be divided into?
vermis, paravermis and hemispheres
what are the three lobes the cerebellum can be divided into?
anterior, posterior and flocculonodular
what does the cerebellum cortex contain?
transverse folds known as folia.
what has more folia humans or mice?
humans
what is the cerebellum attached too?
Brian stem, midbrain, pons and the medulla
How does the cerebellum attach to the brain stem?
via the cerebellar peduncles
How does the cerebellum attach to the mid brain?
connected by the superior peduncle
How does the cerebellum attach to the pons?
via the middle peduncle
How does the cerebellum attach to the medulla?
via the inferior peduncle
How many pairs of deep cerebellar nuclei are there in the white matter?
4
what are the 4 deep cerebellar nucleis?
dentate nucleus
interposed nucleus
fastigial nucleus
vestibular nuclei
what nucleus is associated with the hemisphere and what does it do ?
dentate nucleus -
projects to the red nucleus
and motor cortex via the thalamus for motor planning
what nucleus is associated with the paravermis and what does it do ?
interposed nucleus
Motor nuclei and descending tracts for motor control
what nucleus is associated with the vermis and what does it do ?
fastigal nucleus
Motor nuclei and descending tracts for motor control
what does the vestibular nuclei do?
Control of balance and eye movements
who theorised the function of the cerebellum and when?
marr- 1969
Albus - 1971
what do purkinje cells receive?
sensori-motor information and a learning signal.
what can purkinje ells do?
adapt motor responses appropriately.
what do PC receive excitatory input from?
parallel fibres and climbing fibre
what do PC receive inhibitory input from?
molecular Laye ritnerneurons
what constitute the sole output of the cerebellar cortex?
PC
what do PC cells target?
deep cerebellar nuclei and vestibular nuclei.
what kind of output do PC cells have?
inhibitory
How many GrC inputs can PC cells sample?
150,00
what information do mossy fibres carry, how does this affect PC’s?
sensori-motor information, can excite or inhibit PC
How are inputs to PC cells modulated?
synaptic plasticity
how is plasticity regulated?
via Climbing fibre input
slide 15
research
what can cerebellar lesions lead too?
loss of posture
what does a unilateral cerebellar hemispheric lesion cause?
ipsilateral incoordination of the arm and leg.
what can damage to the cerebellum lead too?
slurring, loss of coordination, unsteady gait and nystagmus.
what is Ataxia ?
Lack of voluntary coordination of muscles including gait abnormality.
what causes Ataxia?
cerebellar damage/dysfunction as a result of lesion, stroke or degeneration.
what symptoms does ataxia have?
vary depending on damaged area
what is the cerebellum comprised of?
cerebellar cortex and deep cerebellar nuclei
