Task 2 Flashcards
(55 cards)
1
Q
What is the cause of parkinson ?
A
- The lost of dopamine in substantia nigra
- > abnormal high inhibitory function of Globus pallidus on thalamus
- Happens when D1 and D2 receptors are broken
- caused by gentic and enviormental effects
2
Q
What is parkinson disease ?
A
- You are less able to move
3
Q
Regarding parkinson disease what would happen if D1 is broken ?
A
- less inhibition to Globus pallidus internal
4
Q
Regarding parkinson disease what would happen if D2 is broken ?
A
- higher inhibtion from straitum to Globus pallidus external
5
Q
How can parkinson being tested ?
A
- Via the saccade test (a quick, simultaneous movement of both eyes )
- reduced in frequency and amplitude (power)
- Also studies on monkey
6
Q
What is meant by neurodegenerarive diseases ?
A
- slow death diseases
7
Q
Which disease is a neurodegenerarive disease ?
A
- parkinson
8
Q
How can we treat parkinson people ?
A
- via gene thearpy
- levodopa
- deep brain stimulation
- integreating stem cells in substranitia nigra
9
Q
How does gene therapy work regarding parkinson ?
A
- correction of a disease phenotype through the introduction of new genetic information
- enhances dopamine lv in straitum
10
Q
How does Levodopa or L dopa work ?
A
- crosses into the brain through the “blood- brain barrier.” Once it crosses, it is converted to dopamine
11
Q
What are the early symptoms of Parkinson ?
A
- slow movements
12
Q
What are late symptoms of parkinson ?
A
- mood and behavioural changes (cognitive change)
- do not like to change rules
13
Q
What is the overall conclusion, why parkinson shows deficits ?
A
- because it is not about the ability to move it is about the lack of INITITATION the movement (start and stop signal)
14
Q
What is Huntignton disease ?
A
- Dance like or randoom not controlabel movements
- change in personality
15
Q
What are the causes of Huntingon disease?
A
- repeated sequence of DNA
- highly inheritability
- cause by one gene
- High cell death in putamen and caudate so less cortex activity
16
Q
Which pathway according to Huntington disease is damaged ?
A
- the indirect pathway (Straitum down to globus pallidus external which then can not send inhibitory function to thalamus
- direvt pathway is fine
17
Q
What are the treatment options regarding huntington disease ?
A
- Deep brain stimulation
- Gene treatment via antisense drug
- > LOOK O IN LECTURE
18
Q
How does deep brain stimulation work ?
A
- movements can be induces with chronic electrical stimulation on motor centers
- implantation of battery-powered generator
19
Q
What is the goal of deep brain stimulation ?
A
- increases dopamine
- try to heal internal segment of the globus pallidus
20
Q
How can it be tested if deep brain stimulation was a succes ?
A
- Reaction time + motor time decreases
- but still bad at making choices
21
Q
What are other functions of the basel ganglia (loops)
A
- cognitive loop
- emotion motiv loop
- oclumotor
- motor
- > look up in slides !!!!
22
Q
What is so special rgearding the thalamus ?
A
- it is tonic = means inhibted
- direct gate towards cortex
23
Q
What is the overall function of the direct pathway ?
A
- making / creating movement -> which is done by taking away the inhibition of thalamus
24
Q
What is the structure of the direct pathway in depth ?
A
- motor cortex says move
- Sends exitatory signal to striatum (glutamate)
- In the striatum it synapses with an inhibitory axon!
- This leads to more inhibition of globus pallidus internal
- Globus pallidus can not inhibt then the thalamus because it is already inhibted which leads to actiavtion of thalamus
- Thalamus sends signal to cortex
25
What is the structure of the indirect pathway in depth ?
1. motor cortex send signal to striatum
2. Straitum sends inhibitory signal to globus pallidus externa
3. When activity is turned down in Globus Pallidus external it can not inhibited Subthalamic nucleus
4. Subthalamic nucleus is more exited
5. Subthalamic nucleus send excitatory signals to Globus pallidus which then becomes more active !!
- > so thalamus gets less active
26
What is the overall function of the indirect pathway ?
- stopping unwanted movement
- Globus pallidus send inhibitory signals to the thalamus which leads to disrupted communication between thalamus and motor cortex
- asking globus pallidus more exited
27
What is the function of the third pathway also called dopamine pathway regarding the direct pathway ?
- D1 tries to exit the thalamus even more via substranita nigra bounding on striatum
- Straitum more activated and sends more inhibitory signal (GABA) to globus pallidus
- > Conclusion globus palidus is even more inhibted
28
When no signal is coming from the cortex to the striatum how is then the globus pallidus charged ?
- indirect and direct pathway balance each other out
29
Which pathway is a bit faster the direct or indirect pathway ?
- the direct pathway !
30
What is the function of the third pathway also called dopamine pathway regarding the indirect pathway ?
- Substanatia nigra gets activated by subthalamic nucleus which then leads to dopaminse release in SN
- dopamine binds on D2 receptor in Straitum -> which makes neuron less exitatory
- Less excitatory signal get passed to globus pallidus external -> thalamus is therefore more active
- >more movemet
31
So what does the dopamine pathway generally speaking do ?
- it supports the direct pathway while reducing the effects of the indirect pathway
32
Do we have saved motor programs ? If so which once and where are they located ?
- Yes
- brain stem and spinal cord
- survival, locomotion, posture, eye movements, breathing, chewing, swallowing and expression of emotions
33
Can the basel ganlglia activate motor movemnts by it self ?
- yes survival instict motor movements tdo not need the cerebral cortex
- Cat example
34
What is the role of the cerebellum ?
- finetuning of movements
| - error based learning
35
What is so sepcial regarding the basel ganglia ?
- that every living organism has the same neuronal organization of the basel ganglia and all depend on dopamine as a gate keeping tool
36
Why do we need so much parental care in comparison to other organsm ?
- cause movement takes for us way more time and is key for independency
37
What is meant by hypokinetic ?
- difficulty expressing movement
| - parkinson
38
What is meant by hyperkinetic ?
- difficulty supressing unwanted movement
| - Huntigton
39
What is the structure of the basel ganglia ?
- Exist out of caudate putamen and globus palidus, substantia nigra and the subthalamic nucleus
40
How does the basel ganglia influence movement ?
- via regulation upper motor neurons
41
What is the main function of the basel ganglia ?
- it forms a loop that links most areas of the cerebral cortex with upper motor neurons
42
Where are the upper motor neurons located ?
- primary motor cortex
- pre motore cortex
- and brainstem
43
What happens when the basel ganglai is damaged ?
- the motor systems cannot switch smoothly between commands that initiate a movement and those that stop the movement.
- unwanted movemnts are expressed
44
What is the function of the straitum ? And out of what does it exist ?
- caudate and putamen
| - input zone
45
What is the function of medium spianl neurons ?
- they can integrate inputs from cortical thalamic and brainstem structure
46
What is the function of the caudate ?
- fires/discharge in anticipation of eye movements
47
What is the function of the putamen ?
- fires/discharge in anticipation of limb and trunk movements
48
On what does the putamen and causte work on together ?
- encode the decision to move toward a goal rather the direction and amplitude of the actual movement
49
Where is the output zone ?
- output zone
| - Globus pallidus and the substantia nigra via thalamus to many subcortical motor structures
50
What is the main function of the substantia nigra pars compacta ?
- location where the main dopaminergic input orignates
51
What does tonic mean ?
- always active
| - on thalamus (allways Inhibited)
52
What does transient mean ?
- one strong activation
53
What is the gate keeping theory ?
- Every movement is inhibited besides the one u want to perceive
- Basle ganglia looks at difference activation lvl
- winner takes it all
54
What is the focused selection theory ?
- Has a center -> direct pathway focuses its influence on particular functional unit in GPi
- has a surround system -> indirect pathway has a more diffuse influence because neurons from subthalamic nucleus are more distributed throughout the GPi
- States every movemnt is ihibited just one has so much exitation so the inhibition does not matter
55
Where does the striatum gets it input from ?
Medium spiny neurons (large, spread out dendrites that integrate inputs from many areas)
