Cerebellum Lecture Flashcards
Main function of the cerebellum
- Motor coordination and correction
- Maybe motor memory component
- able to test directly
Main function of the Basal Ganglia
- Initiation Selection of Motor Programs
- Cannot test directly
Corticospinal tracts
One long axon. Modulation is performed by spinal cord, thalamus (BG and cerebellum)
where does the cerebral cortex send info to
- the spinal cord
- the BG
- Cerebellum
what does the BG send info to
- thalamus
- brainstem
what does the cerebellum send info to
- thalamus
- brainstem
what does the spinal cord send info to
the cerebellum and the thalamus
what is the motor control of the cerebellum
1) maintenance of balance and posture: Vestibular information/ proprioception
2) Coordination of multiple motor groups/ movement. Skilled movement
3) proprioception input: muscle spindle feedback (muscle proprioception
4) Postural Adjustments: Unconscious GTO
5) sensory processing
6) adaptability
7) automaticity: especially in posture
8) motor commands are not initiated in cerebellum; it modifies motor activity accuracy
Motor Learning of the Cerebellum
The cerebellum plays a major role in adapting and fine-tuning motor programs to make accurate movements through a trial-and-error process
Cognitive Functions of the Cerebellum
Involved with cognitive functions such as language. Historically it is considered part of the motor system but cognitive functions are not fully understood yet.
the 4 inputs of the cerebellum
1) anticipates the output of the motor command (coordination of joints)
2) requires proprioception from the muscle spindles
3) requires vestibular information for control of balance and equilibrium
4) controls eye reflexes (fixation on a target and eye coordination
what is the forward model of the cerebellum
predicts the sensory outcome of our movement and actions
The accuracy in time sensorimotor coordination
- is like a copy machine: It creases a replica of our movement in time and produces a “likeness of the pattern”
- If the motor performace has error: the cerebellum corrects via error based learning
Essential aspects of sensorimotor coordination of the cerebellum
- timing
- onset and offset of muscle activation
- direction of movement
although the cerebellum accounts for (x%) of the brains volume, it contains over (y%) of the total number of neurons in the brain
x 10%
y 50%
what sensory input helps compensate for shifts in the body position of changes in load upon the muscles
input from the vestibular receptors and muscle proprioceptors (muscle spindle and GTO)
Lobes of the Cerebellum
medial to lateral
1) vermis
2) intermediate zone
3) lateral hemisphere
inferior
4) flocculonodular lobe
what does the flocculonodular lobe connect directly to
the vestibular system
function of the flocculonodular lobe
1) transport vestibular information
2) equilibrium balance
3) posture
Lateral hemisphere function and motor pathway
function: motor planning for extremities
Pathways: lateral corticopinal tracts
Intermediate hemispheres function and motor pathway
function: distal limb coordination
pathways: lateral corticospinal tract and rubrospinal tract