Cerebellum

Question 1

How many neurones in the cerebellum

Answer 1

70 of the 86 billion neurones in the brain (80%)

Question 2

What are the clinical signs of cerebellar damage

Answer 2

1. Hypotonia 
Reduced tone in muscles 
2. Movement tremor 
Jerky movement/ overshoot-diametria 
3. Ataxia 
General slowness and incoordination
(Alcohol highly effects the cerebellum 

(Ipsilateral effect on body)

Question 3

Describe the ‘uniform cytoarchitecture’

Answer 3

1. Molecular layer
2. Purkinje layer
3. ## Granular layerUniform cytoarchitecture suggests regional differences in fiction due to differences in input and output connections

Question 4

Two main inputs to cerebellum

Answer 4

1. Mossy fibres from all over CNS (mainly pons)
   (cause simply spike outputs)
2. Climbing fibres from inferior olive
   - complex spike

Question 5

Where do Purkinje cells synapse

Answer 5

Deep cerebellar nuclei (white matter)

Question 6

Where do climbing fibres synapse

Answer 6

1:1 Purkinje and climbing fibre connection

Question 7

Describe the differences in anatomy/ physiology and behaviour of mossy and climbing fibres

Answer 7

Mossy
Anatomy: diffuse and indirect via granule cells
Physiology: simple spikes (40-100 Hz)
Behaviour: movement related

Climbing fibres
Specific and direct
Complex spikes
Non movement related

Question 8

Effects of lesions to different areas

Answer 8

Hemispheres: loss of control of limb movement especially eye guided movement
Paravermis: loss of vol movement in limbs
Vermis: loss of balance and control of trunk and limbs