Neuro: Modulation Of Movement By Basal Ganglia And Cerebellum

Front 1

The basal ganglia is a "disinibitory" movement gating circuit. What happens to the striatum, globus pallidus, VA/VL complex of thalamus and motor cortex when

A. the striatum is at rest?
B. the striatum is excited?

Back 1

A.
When the striatum is at rest, the globus pallidus is tonically active inhibiting the VA/VL complex of the thalamus thus no excitation of motor cortex.

B. Excitatory input signals come in from all around the cortex to the striatum. Striatum will transiently inhibit the globus pallidus thereby uninhibiting the VA/VL complex of thalamus allowing other inputs to excite it thus leading to excitation of motor cortex.

Front 2

When the cortex sends excitatory signals to the striatum to request movement, ___________ of striatum inhibit tonic inhibition of globus pallidus interna (GPi) neurons.

Back 2

medium-spiny neurons

Front 3

Striatum is subdivided by the internal capsule into two: putamen and caudate. Which does eye/head movement and which does limb/trunk movement?

Back 3

Caudate : eye/head (multimodal association cortices and eye movement motor areas)

Putamen: limbs/trunk (1st and 2nd somatosensory, visual, premotor and motor, and auditory cortices)

Front 4

What do the dopanergic projections from the substantia nigra pars compacta (SNpc) do?

Back 4

They modulate the receptiveness of the medium spiny neurons in the striatum. Note: Substantia nigra area is affected severely in Parkinson's disease.

Front 5

Regarding circuitry within the basal ganglia system, where does the caudate project to and where does the putamen project to? (hint: 2 each)

Back 5

Within the basal ganglia itself, the caudate project to the substantia nigra pars compacta (SNpc) and the globus pallidus internal (GPi). The putamen projects to the GPi and globus pallidus externa (GPe).

Front 6

True or False:
A single medium spiny neuron will receive input from thousands of corticostriatal axons.

Back 6

True

Front 7

True or False:
A single corticostriatal axon will excite many medium spiny neurons.

Back 7

True

Front 8

True or False:
Medium spiny neurons exhibit high spontaneous activity.

Back 8

False.

They exhibit LOW spontaneous activity.

Front 9

Differentiate the courses of the direct pathway and the indirect pathway.

Back 9

Direct pathway: Caudate/Putamen --> GPi --> thalamus

Indirect pathway: Caudate/ Putamen --> GPe --> subthalamic nucleus --> GPi --> thalamus

Front 10

The [ direct / indirect ] pathway focuses striatal input to specific unit of pallidal neurons for desired movement while the [ direct / indirect ] pathway focuses striatal input to specific unit of pallidal neurons to limit undesired movement.

Back 10

Direct = desired ; Indirect = limit undesired movement

Front 11

Medium spiny neurons all have dopamine receptors. Those that reach the GPi and activate pathways are [ D1 / D2 ] receptors that reinforce the direct pathway.

Back 11

D1

Front 12

Medium spiny neurons all have dopamine receptors. Those that reach the GPe and support and reinforce the indirect pathways are [ D1 / D2 ] receptors that inhibits the spiny motor neuron response to stimulation to cortical excitation.

Back 12

D2

Front 13

D1 receptors effectively modulate [ down / up] the direct pathway while D2 receptors effectively modulate [ down / up ] the direct pathway via the indirect pathway.

Back 13

D1 up ; D2 down

Front 14

The neurodegeneration of substantia nigra pars compacta is known as

A. Huntington's disease
B. Parkinson's disease
C. ALS aka Lou Gehrig's disease

Back 14

B. Parkinson's disease, a HYPOkinetic disease

Front 15

How is the ability to drive motor programming to the frontal cortex's upper motor neurons decreased in an individual with Parkinson's Disease?

Back 15

With less D1 and D2, there will be a diminished responsiveness of the medium spiny neurons. They will not have the ability to turn off the tonic inhibition of the GPi. Also, with regards to the indirect pathway, the decreased D2 will lower the inhibition going to the subthalamic nucleus which will then drive up the excitation it is sending to Gpi which will further limit the ability to transiently quiet the tonic activity of the GPi neurons thus decreasing the ability to drive the motor programming thru to the upper motor neurons.

Front 16

Name the symptoms that occur with Parkinson's Disease. (hint: ~ 7 mentioned in lecture)

Back 16

Dyskenesia. Tremor. Involuntary movements. Inability to drive intended movements. Gait is shuffling. Reduced arm swing. Hard time turning.

Front 17

What is the first line of therapeutics for individuals with Parkinson's Disease? What is it's drawback?

Back 17

L-dopa therapy. L-dopa does not stop the underlying loss of neurons. Eventually there will be no neurons left to respond to L-Dopa therapy. Deep brain stimulation is the next/an alternative surgical step.

Front 18

The neurodegeneration of the caudate and putamen is known as

A. Huntington's disease
B. Parkinson's disease
C. ALS aka Lou Gehrig's disease

Back 18

A. Huntington's disease, a HYPERkinetic disease

Front 19

In Huntington's Disease, the spiny motor neurons located in the striatum, especially those projecting to the external segment (though both external and internal are effected). How does that lead to Huntington's being a HYPERkinetic disease?

Back 19

So we are quieting down the control signal coming from striatum’s external segment. No longer able to modulate the tonic activity of external segment neurons. This will drive up the inhibition that will be sent out to the subthalamic nucleus and internal segment. This will diminish the ability of the subthalamic nucleus to keep the tonic ability of the internal segment. Less tonic activity leads to increase of the sensitivity of internal segment neurons to stimulate. You get involuntary movements that overlay the voluntary movement.

Front 20

There are also two non-motor pathways that involve the basal ganglia. What are they and name some of the processes they are in charge of.

Back 20

Front 21

Which of the following are associated with COGNITIVE processes of the basal ganglia?

A. Emotional control
B. Planning
C. Motivation and behavior
D. Paranoia
E. Thought organization

Back 21

B. Planning
E. Thought organization

Front 22

Which of the following diseases are associated with the COGNITIVE processes of the basal ganglia?

A. Depression
B. OCD
C. Schizophrenia
D. Tourette Syndrome

Back 22

C. Schizophrenia
D. Tourette Syndrome

Front 23

Which of the following is a disease of the EMOTIONAL processes of the basal ganglia?

A. Depression
B. OCD
C. Schizophrenia
D. Tourette Syndrome

Back 23

A. Depression
B. OCD
C. Schizophrenia

Front 24

___________ has to do with planned motor movements,
___________ for motor execution, and __________ has to do with balance and posture.

A. Primary motor cortex, premotor cortex, vestibular nuclei
B. Premotor cortex, primary motor cortex, vestibular nuclei

Back 24

B. Premotor cortex, primary motor cortex, vestibular nuclei

Front 25

True or False:

The cerebellum cortex is the integration processing part of the cerebellum that corrects and adjusts motor and nonmotor functions.

Back 25

True

Front 26

The cerebellum can be divided into three major sections. Name em.

Back 26

- Cerebrocerebellum (for skilled movement, planning/ executing complex movement, critical to speech and writing)
- Spinocerebellum (medial vermis controls proximal muscles, lateral paravermis controls distal muscles. also rate, rage, force and direction)
- Vestibulocerebellum (posture and balance, fixed gaze)

Front 27

Deep cerebellar nuclei can be divided into three groups: fastigial and interposed, and the dentate nucleus.
A.what are the inputs?
B. what are the outputs?
C. which is for motor execution and which is for motor planning?

Back 27

Front 28

Input and output for cerebellum is via cerebellar peduncles.
Which is efferent, afferent, bidirectional?

Back 28

Superior is efferent (to dorsal thalamus --> pre and primary motor cortex and superior colliculus)
Middle is afferent (from pontine nuclei in brainstem)
Inferior is bidirectional (from brainstem and spinal cord; to brainstem).

Front 29

What projection(s) to the cerebellum are involved in planned motor events?

A. input from throughout the cerebral cortex via pontine nuclei to middle peduncle
B. sensory information from vestibular, spinal and trigemeinal inputs via inferior peduncle
C. modulatory signals from inferior olive

Back 29

A. input from throughout the cerebral cortex via pontine nuclei to middle peduncle

Front 30

What projection(s) to the cerebellum are involved in monitoring position and motion of the body?

A. input from throughout the cerebral cortex via pontine nuclei to middle peduncle
B. sensory information from vestibular, spinal and trigemeinal inputs via inferior peduncle
C. modulatory signals from inferior olive

Back 30

B. sensory information from vestibular, spinal and trigemeinal inputs via inferior peduncle

Front 31

What projection(s) to the cerebellum are involved in learning and memory?

A. input from throughout the cerebral cortex via pontine nuclei to middle peduncle
B. sensory information from vestibular, spinal and trigemeinal inputs via inferior peduncle
C. modulatory signals from inferior olive

Back 31

C. modulatory signals from inferior olive

Front 32

Regarding projections from the cerebellum to the cortex, which pathway listed is for planning of volitional movement?

A. Cerebrocerebellum ---> dentate nucleus --> thalamus --> primary/premotor & association cortex
B. Spinocerebellum --> interposed nuclei --> thalamus --> primary/premotor cortex

Back 32

A. Cerebrocerebellum ---> dentate nucleus --> thalamus --> primary/premotor & association cortex

Front 33

Regarding projections from the cerebellum to the cortex, which pathway listed is for executive control of movement?

A. Cerebrocerebellum ---> dentate nucleus --> thalamus --> primary/premotor & association cortex
B. Spinocerebellum --> interposed nuclei --> thalamus --> primary/premotor cortex

Back 33

B. Spinocerebellum --> interposed nuclei --> thalamus --> primary/premotor cortex

Front 34

Regarding projections from the cerebellum to the brainstem, which of the following paths are for regulation of trunk and limb muscle movement?

A. Spinocerebellum --> fastigial nuclei --> reticular formation --> spinal cord
B. Spinocerebellum --> dentate/interposed nuclei --> superior colliculus-->spinal cord
C. Vestibulocerebellum --> vestibular nuclei --> spinal cord
D. Cerebellum --> reticular formation --> spinal cord

Back 34

A. Spinocerebellum --> fastigial nuclei --> reticular formation --> spinal cord

Front 35

Regarding projections from the cerebellum to the brainstem, which of the following paths are for posture/ balance control?

A. Spinocerebellum --> fastigial nuclei --> reticular formation --> spinal cord
B. Spinocerebellum --> dentate/interposed nuclei --> superior colliculus-->spinal cord
C. Vestibulocerebellum --> vestibular nuclei --> spinal cord
D. Cerebellum --> reticular formation --> spinal cord

Back 35

C. Vestibulocerebellum --> vestibular nuclei --> spinal cord

Front 36

Regarding projections from the cerebellum to the brainstem, which of the following paths are for head/eye movement?

A. Spinocerebellum --> fastigial nuclei --> reticular formation --> spinal cord
B. Spinocerebellum --> dentate/interposed nuclei --> superior colliculus-->spinal cord
C. Cerebrocerebellum --> dentate/interposed nuclei --> superior colliculus
D. Cerebellum --> reticular formation --> spinal cord

Back 36

C. Cerebrocerebellum --> dentate/interposed nuclei --> superior colliculus

Front 37

The cortex of the cerebellum is the integrating unit. The layers of the cerebellum cortex are the granule layer cells, mossy fibers and purkinje cells. How are they connected?

Back 37

The granule layer is VERY dense. Mosee cells comes into granule layer and excites them. Purkinje dendrites from granule cells go up to molecular layer. Purkinje cells also are important because they are responsible for conveying the eventual output.

Front 38

Regarding circuits within the cerebellum, ________ per pontine nuclei deliver excitatory input primarily from cerebral cortex for planned movement.

A. climbing fibers
B. mossy fibers
C. purkinje cells

Back 38

B. mossy fibers

Front 39

Regarding circuits within the cerebellum, _______ per inferior olive deliver excitatory modulator from senses per detected error.

A. climbing fibers
B. mossy fibers
C. purkinje cells

Back 39

A. climbing fibers

Front 40

Regarding circuits within the cerebellum, these cells receive mossy fiber input, conveyed to Purkinje cells by parallel fibers (axons).

A. Granular cells
B. Molecular cells

Back 40

A. Granular cells

Front 41

These cells integrate excitation from 200,000 parallel fibers in the circuit within the cerebellum.

Back 41

Purkinje cells

Front 42

Deep cerebellar nuclei are actually recieving the same stimulation from the cerebrum by the mossy fibers as well as stimulation from the inferior olive via the climbing fibers. Deep cerebellar nuclear cell is tonically active, firing back to the thalamus inhibitory information. Via the deep excitatory loop, if tonically active, they maintain what is happening.

BUT if there is a perceived error, that info will come through the ________ and then what will happen?

Back 42

inferior olive climbing cells. Purkinje cell responds more to the intended movement programming info coming in through parallel fibers. Purkinje cell inhibits the deep cerebellar nuclear cell which reduces its tonic current movement. Thus we get on-the-fly adjustment

Front 43

Cerebellar coordination of ongoing movement is via purkinje cell response to ....

Back 43

mossy fiber intended movement input by climbing fibers that indicate an error in actual movement


Purkinje then rectify (adjust gain) of deep cerebellar nuclei neurons that then drive correction of movement

Front 44

True or False:

You cannot correct vestibulo-ocular reflex (VOR) if cerebellum is damaged.

Back 44

True

Front 45

What are some symptoms of cerebellar lesions?

(hint: in lecture, gave 5)

Back 45

- delayed onset of movement
- ataxia (jerky movement, imprecise rate, range, force, direction)
- dysdiadochokinesia (inability to perform rapid alternating movment)
- dysmetria (over/undershooting movement)
- intention tremors

Front 46

True or False:

Spongiform encephalopathies illnesses like mad-cow disease are rapid neurodegenerative disorders affecting cerebellar and cerebro cortex.

Back 46

True

symptoms: cerebellar ataxia, myoclonic jerks, muscle atrophy, seizures and dementia

Front 47

True or False:

Congenital cerebellar malformations like Dandy Walker disease is du eto an enlarged 4th ventricle that displaces cerebellum and occipital cortex causing significant malformation.

Back 47

True

Post-natal symptoms include enlarged cranium, irritability, vomiting, slow vestibular/motor development, vision problems, speech issues.