21.5 Cerebellum Flashcards
What are the different functional subdivisions of the cerebellum? What is the function of each?
- Vestibulocerebellum -> Balance/posture + Eye movement
- Spinocerebellum -> Motor execution (i.e. control of axial and limb muscles)
- Cerebrocerebellum (a.k.a. pontocerebellum) -> Motor planning (i.e. planning and timing precise movements)
What is the anatomical location of the vestibulocerebellum?
Flocculonodular lobe
What is the anatomical location of the spinocerebellum?
Vermis (and intermediate zone)
What is the anatomical location of the cerebrocerebellum?
Lateral cerebellar hemispheres
What are the three layers in the cytoarchitecture of the cerebellum, from innermost to outermost?
Granule cell layer
Purkinje cell layer
Molecular layer
What are the different layers of the cerebellum and what is found in each?
[IMPORTANT]
- Inner layer (Granule cell layer):
- Granule cells
- Mossy fibre inputs
- Golgi interneurons
- Middle layer (Purkinje cell layer):
- Purkinje cells
- Outer layer (molecular layer):
- Purkinje cell dendrites
- Granule cell parallel fibres (note the perpendicular fibres)
- Climbing fibres
- Stellate and basket interneurons
Describe the principle of the molecular layer of the cerebellar cortex.
- It is the outer layer where the Purkinje fibres send their dendrites to receive information from climbing fibres and granule cell parallel fibres. None of these cells actually have their cell bodies here.
- There are also stellate and basket interneurons here.
What are the different cell types found in the cerebellum?
Purkinje, Golgi, granule, stellate, basket.
What are the outputs from the cerebellar cortex to the deep nuclei?
Purkinje cells are the sole output.
*GABA (inhibitory cells)
In which layer does most motor processing take place?
Molecular layer
Mossy fibres provide input to the…
Granule cells
and
Deep cerebellar nuclei
What are the functions of the basket and stellate cells?
- GABAergic inhibitory interneurons
- Send input to Purkinje cells and parallel fibres to induce lateral inhibition and sharpen borders of area activated by the parallel fibres
Between the basket cells and stellate cells, which is long-range and which is short-range?
Basket cells = long-range (large basket)
Stellate cells = short-range (small star)
What are the functions of the Golgi interneurons?
Receive excitatory input from mossy fibres - synapse onto granule cells and their parallel fibres
Feedforward and feedback inhibition
What is the function of the granule cells?
Stimulated by mossy fibres to generate simple spikes in Purkinje cells