Title: BV4 / Modul 3 / The cerebellum in motor control

Q: What is the latin name for cerebellum and what does it mean?
A: Arbor vitae - tree of life

Q: What does cerebellum mean?
A: Little Brain

Q: What can be said about teh cerebellum as a structure?
A: The cerebellum as a structure is highly conservative - Its conserved in all the vertebraes

Q: How big a part does the cerebellum consitute of teh brain size?
A: Consists of 10-40% of the brain size (depending on animal?)

Q: What else tells about the importance of the cerebellum?
A: The number of neurons it contains also tells how important it is

Q: What is the number of neurons the cerebellum consists of in terms of the whole CNS?
A: Contains 50% of the neurons of the whole CNS

Q: From which structures does the cerebellum receive input?
A: - Cerebral cortex (parietal, cingulate, frontal)
- Nucleus ruber
- Spinal cord
- Vestibular nucleus
- Reticular formation
- Locus coeruleus
- Inferior olive

Q: To where does the cerebellum transmitt output?
A: - Motor cotex
- Red nucleus
- Superior colliculus
- Vestibular nucleus
- Reticular formation

Q: What is the ratio of input to output in the cerebellum and what does that suggest?
A: The ratio of input to output is 40:1, suggesting that the cerebellum receives more info than i transmitts

Q: How many types of neurons does the cerebellum contain?
A: 5:
- Granular cells
- Purkinje cells
- Basket cells
- Stellate cells
- Golgi cells

Q: What is the organisation of the cerebellum?
A: Laminar organization (3 layers)

Q: What are the neurons of teh cerebellum organized in?
A: 3 layers (laminar organization)

Q: Which are teh layers of the cerebellum, from outside and in?
A: - Molecular layer
- Purkinje cell layer
- Granular layer

Q: What do we have in the purkinje cell layer?
A: It is
the area where all the somas of the purkinje cells are located, based on where
in the cerebellum it's located its also experimentally accessible

Q: What can be said about the cerebellum and its cells/structures being experimentally accessible?
A: Based on where in the cerebellum the somas of the purkinje cells are located it is experimentally accessible

Q: What is the outermost layer of the cerebellum?
A: Molecular layer

Q: Which is the inner most layer of the cerebllum?
A: Granular layer

Q: Why did neurologists of the past think the cerebellum was a good area to investigate how the brain works?
A: Based on these 3 unique features (5 types of neurons, laminar organisation (3 layers), and experimentally accessible) of the cerebellum neurologists of the past were attrached to the simplicity of the cerebellum and they really thought we could get an understanding of how the brain works using the cerebellum as the main investigation area

Q: Do we know what the cerebellum doe snow after so many years of research?
A: However after 100s of years of research we don't really know what the cerebellum does

Q: What does the cerebellum contribute to with its functions?
A: Motor functions

Q: Which motor functions does the cerebellum affect?
A: - Voluntary movements
- Gait (gång) control
- Posture
- Speech

Q: What can the cerebellum be associated with based on it affecting motor functions?
A: It
can be associated to several differnet motor diseases

Q: Which motor diseases can the cerebellum be associated with?
A: - Ataxia (svårigheter att samordna rörelser)
- Dystonia (muscles contract involuntarily?
- Multiple sclerosis
- Tremor

Q: Which non-motor functions does the cerebellum largely contribute to?
A: - Cognition (language, speech)
- Emotions (fear)
- Sleep
- Visceral responses

Q: Which non-motor disorders are malfunctions of the cerebellum related to?
A: - Autism spectrum disorders (ASD)
- Dyslexia
- Schizophrenia
- Obsessive Compulsive Disorder (OCD)
- Vertigo

Q: How many layers does the cerebellar cortex consist of?
A: 3 layers: Molecular, purkinje, granular layer

Q: What does the molecular layer contain?
A: The molecular layer contains a lot of axons and dendrites of the purkinje cells and also some neurons

Q: What does the purkinje cell layer contain?
A: Purkinje cell somas

Q: What are purkinje cells?
A: The purkinje cells are the principal incomputational perspective and anatomical perspective of the cerebellum - cells of the cerebellar cortex

Q: What is located in te granular layer?
A: We have a massive number of small sized neurons, called granular neuorns, located in the granular layer

Q: What does the granular layer contain?
A: This area contains the massive number of the neurons, that make up 50% of the neurons in the CNS in the cerebellar cortex

Q: What do we have under the cerebellar cortex?
A: White matter

Q: What does the white matter in the cerebellum consist of?
A: Consists from the purkinje cells axons

Q: What are the purkinje cells for the cerebellum and where do their axons go?
A: The purkinje cells are the output cells of the cerebellar cortex and these axons reach other neuorns in the white matter and that region is called the deep cerebellar nuclei, one of these is the dentate nucleu

Q: What does the dentate nucleus do?
A: The output of the cerebellar cortex reaches the neurons in the dentate nucleus and they process the information to generate the output computations of the whole cerebellum

Q: Explain the layers of the cerebellum based on this picture?
A: Outer light layer - molecular layer
Dark layer - granular layer - dark bc it contains many neurons
The purkinje cell layer is not that visible since its a mono-cell layer
U can see the cerebellar nuclei neurons in the middle (arrows pointing) which are the output cells of the cerebellum !!!

Q: Why doe sthe granular layer look dark?
A: Bc it contains many neuorns

Q: What can be said about the thickness of the purkinje layer?
A: It's a mono-cell layer and therefore not that visible

Q: What do granular cells compose?
A: Granular cells that compose the massive number of neurons of the granular cell layer

Q: What type of ergicneurons are granular cells?
A: Glutamatergic

Q: WHich are the only excitatory neurons of the cerebellar microcircuit?
A: Granular cells

Q: From where do te granular cells receive input?
A: These neurons receive strong input from the precerebellar nuclei through a higher number of processes called mossy fibers

Q: What are mossy fibers?
A: Mossy fibers respesent all the input fibers that reaches the granular cell layer and the granular cells arriving from different precerebellar nuclei

Q: From where do mossy fibers come?
A: From different precerebellar nuclei

Q: What do teh granular cells do with the input information received from the mossy fibers?
A: The granular cells then process this input and extend their axons, which is what we call the parallell fibers within the molecular layer of the cerebellum

Q: What are parallel fibers?
A: The axons of granular cells that project into the molecular layer of teh cerebellum

Q: What do teh parallel fibers reach?
A: These fibers reacheds the golgi cells

Q: What are golgi cells?
A: GABAergic interneuons

Q: Where are the golgi cells of the cerebellum located?
A: In the granular cell layer

Q: What do teh golgi cells receive and what do teh do with that information?
A: They
receive the glutamatergic input from the granular cells, they process this input and inhibit the granular cells

Q: What can be said about the relationship of the granular cells and the golgi cells in the cerebellar cortex?
A: So these neurons of the golgi cells along with the granular cells, they form a specific loop, which is made to control the excitability of the granular cells

Q: What will overexcitability of the granular cells lead to?
A: Overexcitement of the granular cells will excite the golgi cells, which will inhibit the granular cells

Q: What else do the granular cells provide input to via the parallel fibers?
A: In addition, the granular cells provide massive input to the purkinje cells, these cells massively process the input to generate the cerebellar cortex output

Q: From where else do the purkinje cells receive input, except from the granular cells (parallel fibers)?
A: Along with the parallel fibers the purkinje cells also receive input from the inferior olive (precerebellar nucleus) through climbing fibers

Q: Which type of fiber projects from the inferior olive to the purkinje cells?
A: Climbing fibers

Q: Why are the climbing fibers called climbing?
A: They are called climbing fibers because these fibers/axons go up to the purkinje cell soma, and then they wrap around them and also around their proximal dendrites

Q: What does the input from the climbing fibers from the inferior olive to the purkinje cells encode for?
A: This input from these fibers is very important that the cerebellum receives, and this imput enconds the error signals

Q: What else do the parallel fibers contact except from golgi- and purkinje cells?
A: In addtion the parallel fibers from the granular cells also contact 2 small populations of molecular layer interneurons, which are called stellate cells and basket cells

Q: Which types of neurons are stellate and basket cells?
A: Interneurons

Q: What do the stellate and basket cells receive from the parallel fibers?
A: Both of these interneurons receive the glutamaterigic input

Q: Which type of ergic are stellate and basket cells?
A: Both
of these as interneurons are GABAergic neurons, they are inhibitory
interneurons

Q: What do the stellate and basket cells provide?
A: They
provide inhibition through the purkinje cells, since they are GABAergic inhibitory interneurons

Q: What do the stellate and basket cells create?
A: So, the stellate and the basket cells perform a 2nd loop, similar to the one bewteen golgi-cells and granular cells, but here it's between the granular cells, the molecular interneurons (stellate & basket) and the purkinje cells, in order to inhibit and control the excitation the purkinje cells receive

Q: Which cells are included in the 2nd loop created by the stellate and basket cells?
A: - Granular cells
- Stellate cells
- Basket cells
- Purkinje cells

Q: What is the purpose of the 2nd loop created by the stellate and basket cells?
A: To
inhibit and control the excitation the purkinje cells receive

Q: Which are the output neurons of the cerebellar cortex?
A: The purkinje cells

Q: HOw are the purkinje cells the output cells of the cerebellum?
A: They
extend their axons to the deep cerebellar nuclei neurons, within the white
matter of the cerebellum, and these neurons process the inhibitory input, since
the purkinje cells are also GABAergic neurons, and then they provide this
output of the cerebellum (the total output of the cerebellum)

Q: What can the purkinje cells be called in the cerebellar microcircuit?
A: The purkinje cells are the principle cells of the cerebellar microcircuit

Q: What are the granular cells?
A: - Granular cells, are a massive number of small size neurons that form the parallel fibers
- These are the only excitatory cells within this microcircuit - glutamatergic

Q: How does input to the cerebellar cortex happen?
A: - Via mossy fibers to the granular cells, from precerebellar nuclei
- Via climbing fibers to the purkinje cells, from the inferior olive (IO)

Q: How does output from the cerebellar cortex happen?
A: Only from purkinje cells to deep cerebellar nuclei

Q: What can be said about the dendrites of purkinje cells?
A: The purkinje cells/neurons have an extensive number of dendrites

Q: What is the function of the large number of dendrites in the purkinje cells?
A: This massive number has a function, since it's a place where the purkinje cells can form approximately 200 000 different synaptic contacts - this is 10-20 times more synapses in the dendrites that the purkinje cells have compared to any other neuron within the body

Q: How many synaptic contancts can purkinje cells form?
A: Approximately 200 000 different synaptic contacts - this is 10-20 times more synapses in the dendrites that the purkinje cells have compared to any other neuron within the body

Q: What do the purkinje cells form (cell structure)?
A: Dendritic spines, which have an extended structure

Q: What is the functions of the dendritic spines of the purkinje cells?
A: They allow the different inputs to arrive and to
accomodate as much as possible in a smaller area

Q: How is the forming of dendritic spines of the purkinje cells similar to what the cerebellum in general does?
A: It's smilar to what the cerebellum in general does, bc in order to accomodate all these different neurons it has also made these ripples - folding - called foliae

Q: Why does the cerebellum have foliae?
A: In
order to accomodate all these different neurons (increased area)

Q: What are the ripples/folding on the surface of the cerebellum called?
A: Foliae

Q: What are these?
A: Dendritic spines of purkinje cells

Q: Which main structures is the cerebellum organized in?
A: - The flocconodular lobe
- The vermis
- The hemispheres

Q: What does teh flocconodular lobe consist of?
A: It consists of the flocculus and the nodulus

Q: What else can the flocconodular lobe be called?
A: This is the archiocerebellum, meaing its the primitive form of the cerebellum

Q: Which part of the cerebellum is the most primitive part?
A: The flocconodular lobe - the archiocerebellum

Q: Which organisms can the flocconodular lobe be seen in?
A: This part of the cerebellum can be seen in all organisms with a cerebellum - the most ancient part

Q: Where is the vermis?
A: In the middle of the cerebellar cortex between the cerebellar hemispheras

Q: What does the vermis consist of?
A: The vermis and paravermis

Q: What is another name of the vermis?
A: This is called the paleocerebellum, meaing old cerebellum

Q: How old is the vermis?
A: Not as old as the flocconodulus, but older than the hemispheres that are the most newly developed

Q: What is another name for the hemispheres?
A: Neocerebellum

Q: Why is the cerebellum divided into the 3 differnet areas?
A: These 3 differnet areas are differnet bc they seem to participate in different functions, based on the input and the output that they have

Q: From where does the flocconodulus receive massive input?
A: The flocconodulus receives massive input from the vestibular system

Q: What is the flocconodulus forming?
A: The flocconodulus receives massive input from the vestibular system and forming what we call the vestibulocerebellum structure

Q: To where does the vermis project?
A: The vermis receives much input and projects to several areas that are important for information processing between the spinal cord and the cerebellum, therefore it forms the spinocerebellar structure of the cerebellum

Q: What does the vermis form?
A: The spinocerebellar struture of teh cerebellum

Q: From where does the hemispheres receive input and project output?
A: The cerebellar hemispheres (neocerebllum), the newest evolutionary form of the cerebellum recieves strong input and projects strong output to the cerebral cortex,  therefore it forms the cerebrocerebellar structure/organisation

Q: What structure do the hemispheres form?
A: The cerebrocerebellar structure/organisation

Q: How can the spinal cord project directly to the cerebellum (spinocerebellum)?
A: The spinal cord can project directly to the cerebellum, these axons called mossy fibers project to the granular cells of the cerebellum, through this cerebellar microcircuit the purkinje cells receive this input and they project the output from the cerebellar cortex to the deep cerebellar nuclei

Q: Where do purkinje cells project output?
A: They project the output from the cerebellar cortex to the deep cerebellar nuclei

Q: What does the deep cerebellar cortex do in terms of input and output (spinocrebellum)?
A: The deep cerebellar nuclei receives input from purkinje cells, processes it and generates the cerebellar output - "inspect " to the spinocerebellar functions

Q: What happens with the output from the deep cerebellar nuclei (spinocerbellum)?
A: This output is projected to the vestibular nuclei and also the reticular formation - the neurons there in the motor system are projeting directly to the spinal cord in order to perform motor function

Q: What type of organisation does the spinocerebellar areas have?
A: The spinocereblar areas have somatotropic organisation, so different parts of the cerebellum processes differnet motor functions related to the foot, arm or face

Q: What does the somatotropic organisation of the spinocerebral area look like in the anterior part of the cerebellum from top to bottom?
A: - Foot (leg)
- Arm
- Face

Q: What does the somatotropic organisation of the spinocerebral area look like in the posterior part of the cerebellum from top to bottom?
A: - Face
- Arm
- Foot

Q: Between what is the cerebrocerebellum conductivity?
A: The cerebrocerebellum conductivity is between the cerebral cortex and the cerebellum

Q: Are there direct connections between the cerebral cortex and the cerebellum when it comes to the input and output of the cerebrocerebellum?
A: There are no direct connections between the 2, in both cases, input and output, are indirect

Q: How is input to the cerebrocerebellum conducted?
A: Projecting neurons from the cortex recahes the pontine nucleus and there communicates with specific neurons that connect to the cerebellar cortex

Q: What are the axons from the pontine nucelus called?
A: Mossy fibers

Q: What do teh axons (mossy fibers) fron teh pontine nucleus contact in the cerebellum (cerebrocerebellum)?
A: Since the pontine nucleus is a precerebellar nucleus, the axons contact the granular cell layers of the cerebellar cortex. and then via parallel fibers the purkinje cells

Q: What do the purkinje cells do in the cerebrocerebellum after receiving input?
A: After
receiving this input they perform their computations and then they project to the
deep cerebellar nucleus, in this case the lateral cerebellar nucleus

Q: Which deep cerebellar nucleus do the purkinje cells project to in cerebrocerebellum?
A: The lateral cerebellar nucleus

Q: What does the lateral cerebellar nucleus do after receiving input from the purkinje cells (cerebrocerebellum)?
A: They
transmitt the cerebellar cortex output - these neurons of the deep cerebellar
nucleus (lateral cerebellar nucleus) recieves this cerebellare input and transmitt this input as
cerebellar  output back to the cerebral
crotex, indirectly mediating their transmission through the thalamus

Q: What does the transmission of output from the lateral cerebellar nucleus (deep cerebellar nucleus) to the cerebral cortex (Cerebrocerebellum)?
A: This transmission is indirectly mediated through the thalamus and from there to teh cerebral cortex

Q: What can be said about the comminication between the cerebral
cortex and the cerebellum (cerebrocerebellum)?
A: - Indirect communictaion between the cerebral cortex and the cerebellum

Q: Where does the vestibulocerebellum recieve input from?
A: The cerebellum recieves input from the vestibular apparatus, either direct or indircet through the vestibular nucleus

Q: In the case of the vestibulocerebellum which neurons are the output neurons?
A: In this case, the purkinje cells are not only the output neurons of the cerebellar cortex but also the output of the cerebellum, meaning that they transmitt their outputs directly without the use of any deep cerebellar nuclei

Q: How do teh purkinje cells project in vestibulocerebellum and to where does that structure project?
A: They project directly to the vestibular nucleus, and then the vestibular nucleus processes this information and transmitts this info either to the spinal cord or to specific nuclei controlling the eye muscles

Q: Why does the vestibulocerebellum use a more direct approach regarding output compared to teh other cerebellar structures?
A: Because the vestibulocerebellum is the oldest part of the cerebellum it uses a more direct approach rather than an indirect approach, like the evolutionary newer parts of te cerebellum

Q: What is the cerebrocerebellum important for?
A: Cerebrocerebellum is important for higher functions and higher motor commands

Q: Via what is the output from the vermis?
A: Output via fastigial nucleus

Q: Which 2 parts does the spinocerebellum consist of?
A: - Vermis
- Medial part of cereellar hemisphere

Q: Via what is the output from the medial part of the cereellar hemisphere?
A: Output via interpositus nucleus, which is composed of the globose and emboliform nucleus

Q: What is the interpositus nucleus composed of?
A: - Globose nucleus
- Emboliform nucleus

Q: Via what is the output from the vestibulocerebellum?
A: Output to vestibular nuclei

Q: Via what is the output from the cerebrocerebellum?
A: Output via dentate nucleus to motor and premotor cortices

Q: What other name is there for the spinocerebellum?
A: Paleocerebellum

Q: What other name is there for the vestibulocerebellum?
A: Archicerebellum

Q: What other name is there for the cerebrocerebellum?
A: Neocerebellum

Q: What are the constituents of the cerebrocerebellum?
A: Lateral part of cerebellar hemisphere

Q: What are the constituents of the vestibulocerebellum?
A: Flocconodular lobe

Q: What is the function of the spinocerebellum?
A: Motor execution

Q: What is the function of the vestibulocerebellum?
A: Balance and eye movements

Q: What is the function of the cerebrocerebellum?
A: Motor planning

Q: Which are the main functions of teh cerebellum?
A: - Control of balance and posture
- Control of voluntary movements
- Role in motor learning
- Parcipitation in cognitive functions

Q: Which are the 3 differnet parts of (motor) learning in the CNS?
A: - Reinforcement learning
- Unsupervised learning
- Supervised learning

Q: Which type of learning does the motor cortex use?
A: The motor cortex uses an unsupervised "learning", meaning that they receive a specific input, they process this input, and they generate a specific output

Q: Which type of learning does the cerebellum use?
A: The cerebellum in motor functions perfoms supervised learning, it receives input, generates corresponding output, however the output now either directly or indirectly through relay areas (inferior olive areas), then from inferior olive cells, the climbing fibers that reaches the purkinje cells in te cerebellum, and they provide error signals

Q: How does supervised learning work?
A: Input is received, it generates corresponding output, however the output now either directly or indirectly through relay areas (IO) they form inferior olive cells, the climbing fibers that reaches the purkinje cells in te cerebellum, and they provide error signals

Q: How does unsupervised learning work?
A: A specific input is received, its processed and a specific output is generated

Q: What doe sthe cerebellum do in supervised learning via the inferior olive areas and climbing fibers to the purkinje cells?
A: The cerebellum though these loops also encodes errors

Q: How does learning work in the cerebellum in conclusion?
A: SO, the cerebellum receives an input, processes the input, generates an output and then the error signals (positive or negative) are coming from these executive parts of the spinal cord and says what happened

Q: How is an error eregated and what does the cerebellum do with them?
A: So when the motion i wanna do doesn't match with what happened then it generates an error, then the cerebellum fixes these commands in order to achieve a better outcome

Q: How does reinforcement learning work?
A: Putamen receives input + reward -> putamen processes -> generates an output

Q: Where do we have reinforcement learning?
A: In the putamen

Q: Why is the inferior olive nucleus important for the cerbellum?
A: The inferior olive nucleus neurons are very important to recieve the the error signals from the spinal cord or other motor regions that tells that what happened wasn't similar to what should happen

Q: How does the inferior olive relay the error signals to the cerebellum?
A: The climbing fibers from the inferior olive goes to purkinje cells and they
perform, through specific synaptic plasticity, long term depression changes in
the synapses of the purkinje cells in order for them to adapt their
coputational performance

Q: How do purkinje cells adapt their computational performance when receiving error signals via climbing fibers from the inferior olive?
A: Through specific synaptic plasticity they perform long term depression changes in the synapses of the purkinje cells in order for them to adapt their computational performance

Q: What generally happens with teh long term depression in the purkinje cells?
A: The long term depression that happens in the purkinje cells involves several different molecular pathways, however the importance is what happens at the synaptic level

Q: What input does the purkinje cells receive that informs about the plan and the execution of an action?
A: - The parallel fibers from the granular cells provide general input to purkinje cells about what we want to do, what the output should be
- While the climbing fibers from the inferior olive enconde information related with what actually happened - if what actually happened doesn't match with what we wanted to happen, the climbing fibers produce a lot of input to the purkinje cells (error signals)

Q: What effect do the climbing fibers with error messages to the purkinje fibers from the IO have?
A: The effect this input has on the purkinje cells is that the input extensively depolarizes the dendrites of the purkinje cells and through these different molecular cascades the purkinje cells  modify and weaken the synapses to the parallel fiber that provide the initial input of what we wanted to do

Q: What happens by weakening the parallel fiber input to the purkinje cells?
A: Through these changes by weaking the parallel fiber input, the purkinje fibers acheive as much as possible of what we wanna do with what actually happens - the motor output

Q: What is meant by the cerebellum having a feed forward processing system?
A: The cerebellum has a feed forward processing system, meaning it receives input and generates an output, it also has supervised learning through the loops, especially through the inferior orbit/circuit neurons

Q: From where does the cerebellum receive input?
A: The cerebellum receives the mossy fibers, either coming from the motor cortex or from any other precerebellar nuclei

Q: Where can the mossy fibers that go to the cerebellum come from?
A: - Motor cortex
- Other precerebellar nuclei

Q: What do teh mossy fibers contact in the cerebellum?
A: The mossy fibers contact the granular cells located in the granular cell layer

Q: What do climbing fibers do?
A: The climbing fibers come from inferior olive neurons, contacting specifically the purkinje cells and convey error signals

Q: Where else can mossy fibers come from?
A: Mossy fibers also come from sensors that have other informations, since mossy fibers will classify all the axons they contact in the granular cell layer

Q: What does the cerebellum do after receiving input from mossy fibers and error signals from climbing fibers?
A: Then the cerebellum produces a feedforward control signal that goes to effectors in order to produce the corresponding output

Q: How can the cerebellum be compared to a computer?
A: The cerebellum its a strong computer in our brain, it uses the same organisation of prossesing in the cerebellum as in computers

Q: How many axons arrive in the cerebellum?
A: Ca 200 milion axons

Q: How many granule cells receive input from the axons that enter the cerebellum?
A: 40 billion granule cells

Q: What is the extensive divergence and convergence of the cerebellum?
A: - The cerebellum receives a high number of different inputs from mossy fibers: 200 milion axons arrive into the cerebellum
- Then the input speads to approx 40 billion granule cells in the cerebellum, so we have a divergens, an expansion of the input to different neurons
- Then after the initial process in the granule cells a convergence output is conducted to some purkinje cells
- Then we have a second convergence to the deep cerebellar nuclei neurons in the cerebellum

Q: What is meant by divergence in teh cerebellum?
A: An expansion of the input to different neurons

Q: What happens with the info regarding divergence and convergence in the cerebellum?
A: This is an expansion of information, the processing, then a convergence of this info in different layers in order to achieve and manage to compute the best output possible

Q: How many purkinje cells are there in the cerebellum?
A: 15 million

Q: How many DCN (deep cerebellar nuclei) neurons are there in the cerebellum?
A: <1 milion

Q: What is anothe rimportant part of organisation in the cerebellum?
A: Modular organisation

Q: What can be said about the microciruits and modular organisation of teh cerebellum?
A: The cerebellar microcircuit composed of the five types of cells/neurons are all forming small modules, small differnet micro circuits that work in parallel

Q: What does the modular organisation of the cerebellum provide (what is the purpose of it)?
A: Having this modular organisation provides that we can work in parallel, in several different tasks, in order to maximize and produce a more efficient output, but also merge and titrate the output accordingly to generate 1 vert targeted output or multiple at the same time oif possible

Q: Which types of strutures is the cerebellum high in?
A: The cerebellum is high in plastic structures, and this plasticity (the life long capacity of the nervos system to constantly change and adapt)

Q: What is meant by plasticity in the nervous system?
A: The
life long capacity of the nervous system to constantly change and adapt

Q: What is one form of structual pasticity of the cerebellum?
A: One form of structual plasticity reflects morphological adaptations of the cerebellum, we can appreaciate on the purkinje cell dendrites where we have dendritic spines, that in the span of minutes can completely re-configure/change in organisation of synapses

Q: Where are the synapses of the purkinje cell dendrites coming from?
A: The synapses of the purkinje cell dendrites are coming from excitatory input from parallel fibers and inhibitory input from the stellate cells and the basket cells, as well as the excitatory input from the precerebellar nuclei, also through the climbing fibers (but that only exists in the proximal dendrites of the purkinje cells)

Q: What is another type of synaptic plasticity?
A: Another type of synaptic plasticity is the long term depression that encode the error signals by weakening the specific synapses coming from the parallel fibers, when the climbing fibers are producing a lot of input, suggesting a lot of errors in the output of the cerebellar commands

Q: WHich 2 types of plasticity can be found in the cerebellum?
A: - Structual plasticity (dendritic spines)
- Synaptic plasticity (long term depression, due to error signals)