L12 - The Cerebellum Flashcards
List the deep cerebellar nuclei
nucleus Fastigii
Nucleus globous
Nucleus emboliformis
Nucleus dentatus
What Are the two input pathways for the cerebellar hemispheres?
Mossy fibres
Climbing fibres
What type of spike does a climbing fibre produce!
Complex spike
What type of spike does a mossy fibre produce?
Simple spik
Outline the experiment regarding cerebellu, physiology in monkeys
Tested active and passive movements in monkeys.
Action - moving hand
Could also be done passively using a dc motor
Found that passive hand movements led to changes in complex spike activity and simple spike changes
Active movements has simple spike frequency changw stronger than the complex spike
What makes up the vestibulo cerebellum?
Vernis and l. Flocculus nodularis
What is the input into the vestibulo-cerebellum?
Visual and vestibular signals
What is the output into the vestibular system?
Occulomotor system, head and neck muscles and balance
What is the input into the ponto-cerebellum?
Nuclei of the pons
What is the output of the ponto cerebellum?
Cortex
What is the input to the spino-cerebellum?
Proprioceptive and tactile signals
What is the output of the spino-cerebellum?
Muscles of the extremities
What are the 5 descending projections of the cerebellum?
Vestibulospinal, reticulospinal
Rubrospinal, tectospinal and corticospinal
Outline how LTD works in the cerebellum
When both the parallel and climbing fibres fire simultaneously this leads to activation of both mGluR (Gq) and VGCC which cause an influx of calcium. This leads to AMPAr internalization.
What are the consequences of LTD in the cerebellum?
Decrease in the parallel synapse activation
Decrease in purkinje activation
Disinhibition of DCN
Facilitation towards the output nuclei therefore activates motor nuclei
Outlone the dart experiment for cerebellAr function
A WT patient throws balls at a board and will adjust to be able to hit the board. Then they wear prism glasses which bends everything to the left. They then adjust to this. When they remove the glasses they are throwing too far to the left therefore adjust to hit the target.
In cerebellar patient no adjustment occurs. So they can never hit the target when wearing the glasses.
Outline the VOR experiment for the cerebellum
Place thumb in front of head and move head – see VOR
Now move whole body – no VOR it is suppressed
In cerebellar patients they are unable to suppress the VOR therefore have pathological nystagmus
Outline the eye blink reflex experiment.
Airpuff after tone to rabbits Control subject began to anticipate puff Cerebellar subject didnt adapt Cathodal mutation inhibits adaptation Anodal mutation increases adaptation
Outline the postural reflex experiment
Shift floor beneath the patient
The affected side never anticipated
The unaffected side anticipates
Outline the flexor reflex experiment
Control patients adjust
Cbl-8 patients do no anticipate
Outlone the raspberry task
Pull locked rod from it’s initial grip position with a 3 finger precision grip. It is UUR.
CS - 1kHz tone 450ms prior to UUR
Shows fastest association known
The associate takes longer/ never in cerebral patients
What is the only output pathway of the cerebellum?
The deep cerebellar nuclei
