Section 3 Lecture 5 Flashcards
T or F? There is a direct pwy from cerebellum to the s.c.
F.
Fxns of cerebellum:
motor learning, sensory/motor integration, coordination
Cerebellar damage:
extensors and flexors do not work in sync
How does the cerebellum influence moves?
via brainstem and cortical M areas
Which sensory systems give input to cerebellum?
All sensory systems: visual, somatic sensation, auditory, vestibular, proprioception (m.spindles, GTO’s…)
Outputs from the cerebellum:
predominantly to motor systems (via brainstem)
T or F? Sensory perception and sensation and the formation of movements is effected with damage to cerebellum.
F
3 major parts of the cerebellum:
cortex, white mater, deep nuclei (sends axons back into brainstem)
Output of cerebellar cortex:
cells of deep nuclei (cerebellum right? Deep nuclei are a separate structure from the cortex, right?)
Thin leaflike structure, e.g., in the cerebellum:
folium
Where does information processing occur in the brain?
cerebellum
2 anatomically and fxnally different fibers of the medulla:
mossy fibers and climbing fibers
T or F? Climbing fiber originate from 2+ nuclei.
F. only one
Most afferent fibers to the cerebellum are:
mossy fibers from s.c. and brainstem
From where do climbing fibers arise?
only from the inferior olive of the medulla
Schematic of basic circuitry in cerebellum:
Fibers enter cerebellum and each sends a branch to the deep cerebellar nuclei and another branch to the cerebellar cortex
How many cell types are found in the cerebellar cortex?
5
How many cell layers are in the cerebellar cortex?
3 layers
List the 5 cell types in the cerebellar cortex:
Granule cells +, purkinje cells -, Golgi cells -, stellate cells -, and Basket cells -
T or F? Dendritic trees and p cells are found in only one x-sectional plane of the cerebellum.
T
How are the cell synapses organized w in the cerebellar cortex?
same cell type, same synaptic relation all over, unlike the cerebral cortex
Which is the only cell type in the cerebellar cortex with excitatory action?
Granule cells
Large cells with elaborate dendritic trees:
Purkinje cells
How is the cerebellar cortex different from the cerebral cortex?
The cerebellar has the same cell types in the same synaptic relation to each other all over the cerebellar cortex.
How does output from the cerebellar cortex leave?
Via Purkinje cells
Where do the axons that project from the cerebellar cortex synapse?
Deep nuclei
How do the AP’s generated by a Purkinje cells differ if it is triggered by a mossy fiber than a climbing fibers?
Mossy: simple spike, Climbing: Complex spike
How can you experimentally determine whether tihe input to a Purkinje fiber is from a mossy fiber or a climbing fiber?
Printout of the APs that are generated
Which have less freq input into Purkinje cells, mossy or climbing fibers?
climbing fibers
how many spikes per second do mossy fibers make?
50-100 simple spikes/ sec
When does the frequency of climbing fiber spikes increase?
during M learning
It is hypothesized that mossy fibers mediate (this) and climbing fibers mediate (this):
ongoing work of cerebellum, M learning
Output of the cerebellum is via:
axons of the deep nuclei
To where does output from the cerebellum project?
brainstem then s.c. and thalamus then cerebral cortex
Cerebellar damage leads to:
lack of coordination (ataxia), intention tremor, inability to make quickly changing moves
Ataxia can result in errors in:
range, rate, force, or direction of movement, intention tremor, dysdiadochokinesis (inability to make rapidly alternating moves)
If the cerebellar pt is sitting still will you see resting tremors?
No
T or F? A lesion to the cerebellum leads to sensory deficits.
F.
What observation leads to a major argument for sensorimotor coordination as the major/only function of the cerebellum?
The fact that damage does not affect sensation at all
Give an example of the type of movement a person with damage to the cerebellum would not be able to perform.
Flip palm to face up, then down quickly
lack of coordination:
ataxia
T or F? You can have damage to the arm and not the leg if the cerebellum is damaged.
T. The damage is localized
Does MS affect input or output axons of the cerebellum?
Can affect either
Symptoms of cerebellar damage can be seen with:
gunshot to head, MS, CP
This is a disease of chronic alcoholics:
Wernickes-Korsakoff syndrome, results from malnutrition, thiamine and vitamin B1 deficiency
Symptoms of Wernickes-Korsakoff syndrome:
Ataxia (lack of coordination)
What is happening at the neurological level with Wernickes-Korsakoff syndrome?
degeneration of cerebellar neurons
Some seizure drug can have this side effect:
degeneration of the cerebellum
What drugs can cause degeneration of the cerebellum?
AED’s (seizure drugs), this can lead to ataxia
The cerebellum might also participate in:
non-motor fxns such as cognition and affect (emotional processes)
