Cerebellum Flashcards
TRUE or FALSE: the cerebellum is highly foliated
TRUE
TRUE or FALSE: the cerebellum has only recenently been known to be involved in motor control
FALSE: long known to be involved in motor control
What are the main body parts that have been mapped on the cerebellum?
hand, foot, mouth
How many motor maps are on the cerebellum?
2
What are the 3 main regions of the mammalian cerebellum? Where are they located on the cerebellum?
- vermis / spino-cerebellum (medial)
- hemispheres / cerebro-cerebellum(lateral)
- vestibulo-cerebellum (most posterior)
What is the oldest region of the cerebellum?
vestibuo-cerebellum
Label the anterior lobe and posterior lobe on the cerebellum diagram on slide 5
slide 5
What is the vestibulo-cerebellum’s main function?
vestibular/eye movements (vestibular ocular reflex)
What is the main function of the cerebellum’s posterior lobe?
cognitive
Describe the cerebellum-cerebral cortex loop.
- deep cerebellar nuclei
- thalamus
- cerebral cortex
- pontine nuclei
- cerebellum
(back to nuclei)
Mos of the neurons in the brain are __________________ _________________ cells.
cerebellar granule
.The cerebellum has a ________________ cortex
laminated
TRUE or FALSE: grey matter forms the core of the cerebellum, where the cerebellar nuclei are located
FALSE: white matter
Where does majority of cerebellar output go to?
cerebellar nuclei
What are the 3 cell layers that make up the cerebellar cortex? Which one is outermost? innermost?
- granule cell layer (inner)
- Purkinje cell layer (middle)
- molecular cell layer (outer)
TRUE or FALSE: the molecular cell layer is a single-celled layer
FALSE: the Purkinje cell layer is a single-celled layer
TRUE or FALSE: purkinje cells are very smalle
FALSE: large
To which layer do the purkinje cell dendritic trees extend?
molecular layer
Which cells make up the sole output of the cerebellar cortex?
Purkinje cells
In which plane are the dendritic trees of the Purkinje cells located?
sagittal plane
What are the 2 types of inputs to the Purkinje cells in the cerebellum?
- climbing fibers (inferior olive)
- granule cells (parallel fibers)
Which fibers split and go through all purkinje cells?
granule cells (parallel fibers)
From how many parallel fibers does each Purkinje cell receive input?
200,000
From how many climbing fibers does each Purkinje cell receive input?
1
On a Purkinje cell recording, which fibers cause complex spikes? simple spikes? Draw the diagram and label.
- complex spikes = climbing fiber
- simple = parallel fibers
- slide 9
Which nucleus is major input to the spinocerebellum from? What is the main function of this nucleus?
Clarke’s dorsal nucleus; proprioception
Which nucleus is major input to the inferior olive / climbing fiber from?
nucleus ruber
Which nucleus is major input to the vestibulocerebellum? What is the main function of this nucleus?
vestibular nuclei; posture/balance
Which nucleus does majority of the input to the cerebellum come from? Where does this nucleus get its input from?
- pontine nuclei
- gets its input fro MI, MII, SI, and beyond
Cerebellum is integrating motor _______________ with __________________.
commands; feedback
Draw a diagram to show the commands vs feedback that the cerebellum integrates.
slide 12
What are the commands to the cerebellum?
- frontal/parietal cortex
- red nucleus
- pontine nuclei
- inferior olive
What is the feedback to the cerebellum?
- spinal cord
- vestibular nuclei
Where do the Purkinje cell outputs in the cerebellum go to?
vestibular nuclei and deep cerebellar nuclei
Where does major output from the cerebellum come from?
deep cerebellar nuclei
TRUE or FALSE: deep cerebellar nuclei outputs from the cerebellum are glutamatergic
FALSE: GABAergic (inhibitory)
List the cerebellar nuclei.
- fastigial nucleus
- globose and emboliform nuclei (interposed nuclei)
- dentate nucleus
In general, where does the dentate nucleus mainly project to? Which tracts does it influence?
- ventrolateral and ventroanterior thalamus
- CST
Where does the dorsal dentate mainly project to? Is this the motor or non-motor dentate? Which basal ganglia loop is this circuit similar to?
- dorsal dentate –> ventrolateral thalamus –> MI, SMA, PMC
- motor dentate
- similar to sensori-motor loop
Where does the ventral dentate mainly project to? Is this the motor or non-motor dentate? Which basal ganglia loop is this circuit similar to?
- ventral dentate –> ventroanterior thalamus –> PFC, posterior parietal cortex
- non-motor dentate
- similar to associative loop
Where do the interposed nuclei mainly project to? Which tract does it influence? What does it mainly control?
- nucleus ruber
- rubro-spinal tract
- control of upper limbs
Where does the fastigial nucleus mainly project to? What does it mainly control?
- vestibular nuclei and reticular formation
- balance/posture, locomotion
Draw the cerebellum-cerebral cortex loop on slide 15
Slide 15
What does the cerebellum do?
motor adaptation (learning)
(i.e. it teaches)
Provide an example of motor adaptation that wouldn’t be possible without the cerebellum.
- vestibular ocular reflex
- cut lateral rectus of one eye (bad eye)
- cover bad eye –> no improvement of VOR positioning in bad eye
- cover good eye –> VOR positioning improves in bad eye; good eye moving too much now
The eye providing _________ info determins ____________ success.
sensory; tracking
Which fiber carries the error signal to the purkinje cell when the cerebellum is involved in motor adaptation? How does this error signal allow for motor adaptation when VOR is weakened in one eye? Which fiber would be considered the teacher in this case?
- climbing fiber = teacher; carries error signal
- modifies the parallel-fiber synapses to STRENGTHEN motor command in the bad eye
When the VOR is out of register using minifying glasses, the eyes move too ____________ in relation to image movement on the retina when the head moves.
far
When the VOR is reset by cerebellum when using minifying glasses, the eyes move ______________ distanes in relation to head movement to compensate
smaller
How does motor adaptation when VOR is weakened in both eyes via minifying glasses work?
- climbing fiber carries the error signal
- modifies the parallel fiber synapses to REDUCE strength of motor command (b/c moving too much when VOR out of register)
what is cerebellar ataxia?
cerebellar defects that lead to defects in complex motor behaviours
Describe the cerebellar gait
unsteady and halting
What is cerebellar hypoplasia?
incomplete cerebellar development
