what is the basal ganglia responsible for

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The basal ganglia are a set of subcortical nuclei in the cerebrum that are involved in the integration and selection of voluntary behaviour. Habits can be operationally defined as instrumental behaviour that is impervious to changes in the value of the outcome and in the causal contingency between action and outcome.

How is the basal ganglia involved in habit formation?

Those with basal ganglia damage had problems with visual working memory no matter which part of the visual field was shown the image. In other words, basal ganglia lesions caused a more broad network deficit, while prefrontal cortex lesions resulted in a more limited, and recoverable, deficit.

How does damage to the basal ganglia affect working memory?

While the basal ganglia are primarily involved in movement, they are also connected to the prefrontal cortex. Since the prefrontal cortex helps regulate our behavior, it seems that the basal ganglia may play a role in that as well. This explains why many people with basal ganglia damage develop obsessive-compulsive disorder.

How is the basal ganglia connected to the prefrontal cortex?

Basal ganglia (Corpus striatum) The basal ganglia, or basal nuclei, are a group of subcortical structures found deep within the white matter of the brain.They form a part of the extrapyramidal motor system and work in tandem with the pyramidal and limbic systems.. The basal ganglia consist of five pairs of nuclei: caudate nucleus, putamen, globus pallidus, subthalamic nucleus, and substantia ...

What does basal ganglia stand for?

What is the most important part of the basal ganglia?

The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas....Basal gangliaTA25559FMA84013Anatomical terms of neuroanatomy11 more rows

What happens if basal ganglia is damaged?

Damage to the basal ganglia cells may cause problems controlling speech, movement, and posture. This combination of symptoms is called parkinsonism. A person with basal ganglia dysfunction may have difficulty starting, stopping, or sustaining movement.

What movement does the basal ganglia control?

Basal ganglia mediate some and other higher cortical functions as well, such as planning and modulation of movement, memory, eye movements, reward processing, and motivation. This article will discuss the anatomy and function of the basal ganglia.

What is the function of the basal ganglia quizlet?

The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, & emotion.

Can you live without a basal ganglia?

You Cannot Have a Vertebrate Brain Without a Basal Ganglia.

What disorders are associated with the basal ganglia?

Associated disordersParkinsonism.Huntington's disease.Dystonia.Hemiballismus.Epilepsy.Tourette syndrome/obsessive–compulsive disorder.Sydenham's chorea.PANDAS.More items...

What is basal ganglia stroke?

This type of stroke occurs when blood leaks from a burst, torn, or unstable blood vessel into the tissue in the brain. The buildup of blood can create swelling, pressure, and, ultimately, brain damage. Many basal ganglia strokes are hemorrhagic strokes, which often result from uncontrolled high blood pressure.

Is the basal ganglia involved in attention?

The communication between the prefrontal cortex and specific regions of the visual cortex that is necessary to focus attention is controlled by the basal ganglia.

What does the left basal ganglia control?

Introduction. The “basal ganglia” refers to a group of subcortical nuclei within the brain responsible primarily for motor control, as well as other roles such as motor learning, executive functions, emotional behaviours, and play an important role in reward and reinforcement, addictive behaviours and habit formation.

Where are the basal ganglia?

The structures generally included in the basal ganglia are the caudate nucleus, putamen, and globus pallidus in the cerebrum, the substantia nigra in the midbrain, and the subthalamic nucleus in the diencephalon. The word basal refers to the fact that the basal ganglia are found near the base, or bottom, of the brain.

Which of the following happens in the basal ganglia of a patient with Parkinson's?

The most prominent signs and symptoms of Parkinson's disease occur when nerve cells in the basal ganglia, an area of the brain that controls movement, become impaired and/or die. Normally, these nerve cells, or neurons, produce an important brain chemical known as dopamine.

What are the functions of the cerebellum and basal ganglia?

Abstract. The basal ganglia and cerebellum are major subcortical structures that influence not only movement, but putatively also cognition and affect. Both structures receive input from and send output to the cerebral cortex. Thus, the basal ganglia and cerebellum form multisynaptic loops with the cerebral cortex.

How does the basal ganglia affect behavior?

The basal ganglia (BG) are a collection of subcortical nuclei critical for voluntary behavior. According to the standard model, the output projections from the BG tonically inhibit downstream motor centers and prevent behavior. A pause in the BG output opens the gate for behavior, allowing the initiation of actions.

Can you recover from basal ganglia damage?

Your short-term and long-term outlook after a basal ganglia stroke depends on how quickly you were treated and how many neurons were lost. The brain can sometimes recover from injury, but it will take time. Be patient and work closely with your healthcare team to take steps toward recovery.

Can damage to basal ganglia be reversed?

One of the best ways to restore function and treat basal ganglia brain damage is through neuroplasticity. Neuroplasticity refers to the brain's ability to repair itself, create new neural pathways, and strengthen existing ones. Pathways are best enhanced through repetitive exercise, or massed practice.

What happens if the primary motor cortex is damaged?

When an injury damages the primary motor cortex, the person will typically experience a loss of coordination and poor dexterity. For example, the person usually loses the ability to perform fine motor movements that involve the muscles of the hands, fingers, and wrists.

What is the basal ganglia?

The basal ganglia consist of the corpus striatum (a major group of basal ganglia nuclei) and related nuclei. The basal ganglia are involved primarily in processing movement-related information. They also process information related to emotions, motivations, and cognitive functions. Basal ganglia dysfunction is associated with a number ...

How do basal ganglia receive information?

The basal ganglia receive information from the cerebral cortex and thalamus through input nuclei. After the information has been processed, it is passed along to intrinsic nuclei and sent to output nuclei. From the output nuclei, the information is sent to the thalamus. The thalamus passes the information on to the cerebral cortex.

What is the effect of Gaba on the pallidus?

GABA has an inhibitory effect on motor function . The external segments of the pallidus are intrinsic nuclei, relaying information between other basal ganglia nuclei and internal segments of the pallidus. The globus pallidus is involved in the regulation of voluntary movement.

What are some examples of basal ganglia disorders?

Examples of these disorders include Parkinson's disease, Huntington disease, dystonia ( involuntary muscle contractions), Tourette syndrome, and multiple system atrophy ( neurodegenerative disorder). Basal ganglia disorders are commonly the result of damage to the deep brain structures of the basal ganglia.

Why is my basal ganglia slow to walk?

This damage may be caused by factors such as head injury, drug overdose, carbon monoxide poisoning, tumors, heavy metal poisoning, stroke, or liver disease. Individuals with basal ganglia dysfunction may exhibit difficulty in walking with uncontrolled or slow movement.

Where are the globus pallidus located?

Globus Pallidus: These paired nuclei (one in each hemisphere) are located near the caudate nucleus and putamen. The globus pallidus is divided into internal and external segments and acts as one of the major output nuclei of the basal ganglia. It sends information from basal ganglia nuclei to the thalamus.

Which segment of the basal ganglia is responsible for motor control?

The pars reticulata segment forms one of the major inhibitory outputs of the basal ganglia and assists in the regulation of eye movements. The pars compacta segment is composed of intrinsic nuclei that relay information between input and output sources. It is involved mainly in motor control and coordination.

What are the functions of the basal ganglia?

There are multiple circuits that pass through the basal ganglia: 1 The motor circuit, which plays a role in voluntary movement 2 The oculomotor circuit, which plays a role in eye movement 3 The associative circuit, which plays a role in executive functions like behavioral inhibition (preventing impulsive behaviors) planning and problem solving, and mediating socially appropriate behaviors 4 The limbic or emotional circuit, which plays a role in the processing of emotion and reward.

Where does the information from the basal ganglia come from?

The principal source of input to the basal ganglia is from the cerebral cortex. This input is glumatergic and therefore, excitatory.

What is the primary output region of the basal ganglia?

The primary output region of the basal ganglia is the internal segment of the globus pallidus. This region sends inhibitory GABAergic projections to nuclei in the thalamus. This inhibitory output has a tonic, constant firing rate, which allows the basal ganglia output to both increase and decrease depending on the situation. The thalamus then projects back out to the cerebral cortex, primarily to motor areas.

What are the subcortical structures located at the base of the forebrain?

The basal ganglia are subcortical structures located at the base of the forebrain. They are comprised of the caudate and putamen, which both make up the striatum, as well as the globus pallidus, substantia nigra, and subthalamic nucleus.

Which pathway is activated when input from the cortex or substantia nigra increases in intensity?

Activation of the Direct Pathway. When input from either the cortex or substantia nigra increases in intensity, the direct pathway is activated. The neurons in the striatum involved in the direct pathway express the D1 metabotropic dopamine receptor, and the activation of this receptor is excitatory.

Which part of the brain sends glutamate projections to the thalamus?

Figure 27.7. The cortex sends glutamate projections to the striatum. The substantia nigra sends dopamine projections to the striatum, which are excitatory, acting on D1 receptors in the neurons involved in the direct pathway. The striatum sends GABA projections to the internal segment of the globus pallidus (GPi). The GPi sends GABA projections to the thalamus. The thalamus sends glutamate projections to the cortex. ‘Basal Ganglia Direct Pathway – Text’ by Casey Henley is licensed under a Creative Commons Attribution Non-Commercial Share-Alike (CC BY-NC-SA) 4.0 International License.

Which segment of the globus pallidus sends glutamate projections to the cortex?

Figure 27.5. The internal segment of the globus pallidus sends GABA projections to the thalamus. The thalamus sends glutamate projections to the cortex. ‘Basal Ganglia Output – Text’ by Casey Henley is licensed under a Creative Commons Attribution Non-Commercial Share-Alike (CC BY-NC-SA) 4.0 International License.

What is the significance of the basal ganglia?

The basal ganglia are an assemblage of structures positioned within the cerebral hemispheres. Within the basal ganglia are even more fun things! Firstly, note that the basal ganglia extend over more than just the cerebrum.

Why are basal ganglia important?

As you’ve seen, the basal ganglia are heavily involved in many different functions that are vital to survival and human cognition. This is why any damage to the basal ganglia can result in many different types of neurological disorders.

What is the role of the basal ganglia in the skeletal muscle?

This pathway functions by conducting signals for action (movement) to the nerves that connect the cerebral cortex to the motor neurons, which then activate the skeletal muscles.

What is the effect of repeated exposure to a stimulus on the basal ganglia?

With repeated exposure to a certain stimulus, a person is able to refine their reaction and the basal ganglia work to increase the frequency with which this action is performed.

Which pathway excites the thalamic structures that then excite the cortical neurons?

The direct pathway excites the thalamic structures which then excite the cortical neurons; whereas the indirect pathway inhibits thalamic neurons, suppressing their ability to excite motor cortex neurons. The standard functioning of the basal ganglia requires the perfect balance between these two pathways.

Which part of the brain is responsible for the selection and activation of various cognitive, executive, and emotional programs?

Regarding cognition, the basal ganglia are involved in the selection and activation of various cognitive, executive, and emotional programs that are stored in the prefrontal association cortex and the limbic cortex. The prefrontal association cortex ( PFC) is a portion of the brain located in the frontal lobe and is referred to as the “center ...

Which ganglia control muscle memory?

The basal ganglia play their role in muscle memory because they can directly control the intensification and suppression of activities based on their outcome.

What is the role of the basal ganglia in the brain?

The “basal ganglia” refers to a group of subcortical nuclei within the brain responsible primarily for motor control, as well as other role s such as motor learning, executive functions, emotional behaviours, and play an important role in reward and reinforcement, addictive behaviours and habit formation. The basal ganglia are located ...

Where is the basal ganglia located?

The basal ganglia are located at the base of the forebrain (cerebrum) and have attracted attention in medicine for various disturbances that appear with dysfunctions caused by diseases or trauma. Disruption of the basal ganglia network forms the basis for several movement disorders eg Parkinson's Disease, Huntington Disease.

What is the structure of the basal ganglia?

Structure. The basal ganglia are a cluster of subcortical nuclei deep to cerebral hemispheres. The largest component of the basal ganglia is the corpus striatum which contains the caudate and lenticular nuclei (the putamen, globus pallidus externus, and internus), the subthalamic nucleus (STN), and the substantia nigra (SN).

What is the basal ganglia network?

The basal ganglia network is now viewed as multiple parallel loops and re-entering circuits whereby motor, associative, and limbic territories are engaged mainly in the control of movement, behaviour, and emotions. These parallel circuits subserve the other functions of the basal ganglia engaging associative and limbic territories.

Which model shows how information flows through the basal ganglia back to the cortex?

Proposed more than two decades ago, the classical basal ganglia model shows how information flows through the basal ganglia back to the cortex through two pathways with opposing effects for the proper execution of movement.

What is the most notorious disease of the basal ganglia?

Parkinson's. Parkinson's is the most notorious disease of the basal ganglia. Classic clinical symptoms include bradykinesia, resting tremor, postural instability, and shuffling gait. This disease is a result of neurodegeneration of the SNpc dopaminergic neurons.

Which structure is involved in the pathophysiological processes of psychiatric disorders?

Pathophysiological processes underlying psychiatric disorders such as depression and obsessive-compulsive disorder involve the basal ganglia and their connections with many other structures (particularly to the prefrontal cortex and the limbic system).

What is the basal ganglia?

anatomy. ... (Show more) ... (Show more) Basal ganglia, group of nuclei (clusters of neurons) in the brain that are located deep beneath the cerebral cortex (the highly convoluted outer layer of the brain). The basal ganglia specialize in processing information on movement and in fine-tuning the activity of brain circuits ...

How do basal ganglia work?

Although the basal ganglia are a distinct part of the motor system, they appear to work in concert with the pyramidal motor pathway—the path that conducts signals for action directly along nerve tracts that descend from the cerebral cortex to the motor neurons that activate skeletal muscles. The basal ganglia refine action signals from the cortex, thereby ensuring that an appropriate motor plan is communicated to the muscles. Unlike the pyramidal pathway, the basal ganglia process information indirectly in a set of loops, whereby they receive input from the cortex and return it to the cortex via the thalamus. In that way the basal ganglia modify the timing and amount of activity that leaves the cortex and travels down the pyramidal pathway, amplifying activity that leads to a positive outcome and suppressing activity that leads to a deleterious outcome in a particular situation.

What is the input nucleus of the basal ganglia?

The major input nucleus of the basal ganglia is the striatum (collectively including the dorsal and ventral divisions), which receives information from almost all areas of the cortex. The dorsal striatum (upper region of the striatum) receives information from areas below the cortex (e.g., the midbrain) via the thalamus. In the motor circuit the subthalamic nucleus serves as an input nucleus, receiving information from the cortex and thalamus and influencing the conventional route of basal ganglia outflow from the striatum to the output nuclei of the thalamus. The output nuclei of the basal ganglia are the globus pallidus internus and substantia nigra pars reticulata in the motor pathway and the ventral pallidum in the limbic pathway. Information that exits the basal ganglia goes to the thalamus, primarily the ventroanterior and ventromedial motor thalamic nuclei for the motor pathway and the mediodorsal thalamic nucleus for the limbic pathway, and then is sent back to the appropriate part of the cortex.

How does the brain select actions?

Action selection is facilitated by the nature of the parallel pathways, the number of neurons involved in the processing of information as it progresses through the basal ganglia, and the manner in which these neurons are arranged. The input and output nuclei generally contain the largest and smallest numbers of neurons, respectively. As information progresses through the basal ganglia, each neuron integrates information that has been transmitted from many other neurons in preceding nuclei; hence, the signal becomes increasingly focused and specific as it passes through the basal ganglia. The process of determining which signals are promoted occurs early in the basal ganglia circuit—at the striatum; the neuromodulator dopamine plays a key role in signal promotion.

What are the functions of parallel pathways in the basal ganglia?

Parallel pathways within the basal ganglia circuits facilitate signal promotion and signal inhibition. Neighbouring pathways carrying information about elements of the same desired movement successively amplify the promoted signal as it progresses through the basal ganglia. More often, however, neighbouring pathways act to reduce unwanted signals, ensuring that an accurate, precise, and optimized action plan is developed. In the absence of action selection, all motor plans are promoted and many muscles around the body are activated, leading to a failure to execute desired actions.

Which part of the brain controls the signaling pathways?

The striatum, which serves as a gateway for the regulation of signals through the basal ganglia during the learning of actions and the selection of desirable actions, has the most-complex signaling architecture. In addition to receiving vast external excitatory input from the cortex and thalamus, it also contains several types of interneurons (neurons that connect sensory and motor circuits) and some of the highest levels in the brain of the neurochemicals dopamine and acetylcholine. Collectively, these substances modulate the way in which excitatory inputs are processed and contribute to the final output from the striatum.

Where does information from the basal ganglia go?

Information that exits the basal ganglia goes to the thalamus, primarily the ventroanterior and ventromedial motor thalamic nuclei for the motor pathway and the mediodorsal thalamic nucleus for the limbic pathway, and then is sent back to the appropriate part of the cortex.

What is the role of the basal ganglia in the brain?

Experimental studies show that the basal ganglia exert an inhibitory influence on a number of motor systems, and that a release of this inhibition permits a motor system to become active. The "behavior switching" that takes place within the basal ganglia is influenced by signals from many parts of the brain, including the prefrontal cortex, which plays a key role in executive functions. It has also been hypothesized that the basal ganglia are not only responsible for motor action selection, but also for the selection of more cognitive actions. Computational models of action selection in the basal ganglia incorporate this.

Where is the basal ganglia located?

The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas.

What is the function of the subthalamic nucleus?

The role of the subthalamic nucleus is to stimulate the SNr-GPi complex and it is part of the indirect pathway. The subthalamic nucleus receives inhibitory input from the external part of the globus pallidus and sends excitatory input to the GPi.

What are the components of the basal ganglia?

The main components of the basal ganglia – as defined functionally – are the striatum, consisting of both the dorsal striatum ( caudate nucleus and putamen) and the ventral striatum ( nucleus accumbens and olfactory tubercle ), the globus pallidus, the ventral pallidum, the substantia nigra, and the subthalamic nucleus.

What is the TA2 ganglia?

TA2. 5559. FMA. 84013. Anatomical terms of neuroanatomy. The basal ganglia (or basal nuclei) are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an external and internal region, ...

Which part of the brain receives input from the basal ganglia?

The largest component, the striatum (dorsal and ventral), receives input from many brain areas beyond the basal ganglia, but only sends output to other components of the basal ganglia. The globus pallidus receives input from the striatum, and sends inhibitory output to a number of motor-related areas.

Which ganglia regulates what enters and what doesn't enter working memory?

The basal ganglia has been proposed to gate what enters and what doesn't enter working memory. One hypothesis proposes that the direct pathway (Go, or excitatory) allows information into the PFC, where it stays independent of the pathway, however another theory proposes that in order for information to stay in the PFC the direct pathway needs to continue reverberating. The short indirect pathway has been proposed to, in a direct push pull antagonism with the direct pathway, close the gate to the PFC. Together these mechanisms regulate working memory focus.

Why do we use the basal ganglia?

However, most people still use the term basal ganglia out of familiarity. The basal ganglia communicates with other regions of the brain to allow us to do tasks like driving a car. It's responsible for executing a skill pattern (something you've had to learn) that you can do with very little thought.

Why is the basal ganglia so distressing?

Because the basal ganglia is involved in so many everyday actions, it can be distressing when it starts to break down. For example, a person with Parkinson's disease, which can result from a malfunctioning basal ganglia, exhibits jerky, uncontrollable movements and often has difficulty performing simple tasks like typing or opening a jar. This is because the basal ganglia is failing at its job of executing a movement decided upon by the individual. Even if the movement is initiated, it can be abnormally slow.

What part of the brain is responsible for a person's intelligence?

Rather, it receives a message from a huge part of the brain called the cerebral cortex . This is the area that contains many essential functions. Personality, intelligence, reason, and judgment are all linked to the cerebral cortex. It's also where a thought might pop into your head, as in, 'Ooh, I really like those shoes! I think I'll try them on!'

What is the ganglia?

The ganglia part of the name refers to a cluster of neurons that sits outside of the central nervous system, which is the brain and spinal cord. The basal ganglia has to make sure you execute skill patterns, which are skills you've had to learn, a skill you've practiced.

What is the role of the thalamus in the brain?

The basal ganglia, also known as basal nuclei, is a region on the underside of the brain that plays a very important role in muscle coordination and movement. The ganglia part of the name refers ...

Which part of the brain is responsible for coordinating movement?

In other words, it receives a command from the cerebral cortex, the area of the brain that contains many essential functions, like personality, intelligence, and reason, telling it what the person wants to do, then helps coordinate the movement without requiring too much concentration or thought.

What part of the brain is responsible for tying shoes?

The basal ganglia can sort among all possible movements that could allow us to try on shoes, then decide upon the best one. The thalamus also plays a large part in the execution of movement, in that it relays information to and from the cerebral cortex. Think of the thalamus as an old school operator who had to physically move wires in and out in order to route incoming calls to the proper location.

What are the functions of the basal ganglia?

The basal ganglia is a cluster of nuclei found deep to the neocortex of the brain. It has a multitude of functions associated with reward and cognition but is primarily involved in motor control. In particular, the basal ganglia is considered to be a gate-keeping mechanism for the initiation of motor movement, effectively choosing which actions to allow and which actions to inhibit. In addition, nuclei of the basal ganglia project to limbic and prefrontal regions of the thalamus and cortex and function in a similar way to manifest executive decision-making and reward or aversion emotional stimulation. A number of landmark motor disorders affect the basal ganglia such as Parkinson and Huntington disease which disturb motor control in markedly different contexts.

What is the basal ganglia?

The basal ganglia are a cluster of subcortical nuclei deep to cerebral hemispheres. The largest component of the basal ganglia is the corpus striatum which contains the caudate and lenticular nuclei (the putamen, globus pallidus externus, and internus), the subthalamic nucleus (STN), and the substantia nigra (SN). These structures intricately synapse onto one another to promote or antagonize movement.

What is the nigrostriatal pathway?

The nigrostriatal pathway serves as a basal ganglia input and modulates the direct and indirect pathways. The substantia nigra pars compacta (SNpc) sends dopamine to the striatum via this pathway. As mentioned, the striatum has a population of neurons that are excited by dopamine because they express the D1-family of dopamine receptors as part of the “Direct pathway.” Therefore, dopamine will depolarize this population of striatal neurons and increase activity in the “Direct pathway.” The striatum also has a population of neurons, the “Indirect pathway” which are inhibited by dopamine as they express the D2-family of dopamine receptors. Dopamine will hyperpolarize this population and inhibit the “Indirect pathway.” Thus the SNpc amplifies the response of the basal ganglia by exciting the direct and inhibiting the indirect. A tonic release of dopamine preferentially modulates the D1 receptor, and this is a powerful modulator of the nigrostriatal pathway. [5]

What are the two nuclei of the substantia nigra?

The substantia nigra is composed of two distinct nuclei, the inhibitory pars reticulate (SNpr) and the dopaminergic pars compacta (SNpc). These nuclei are situated in the midbrain lying dorsal to the cerebral peduncles. The substantia nigra derives its name from its dark, neuromelanin pigment formed along the same biosynthetic pathway as dopamine. These dopaminergic neurons of the SNpc receive inputs through the ascending reticular activating system, a deep network of brainstem nuclei, and ascending collaterals that regulate alertness and prime automatic functions prior to cortical awareness and are a way of refining or preselecting appropriate motor, executive, limbic and autonomic responses.[2]  The dopaminergic projections of the SNpc synapse on the putamen and the caudate nuclei of the striatum. The SNpr sends inhibitory axons to the ventral anterior (VA) and ventrolateral (VL) nuclei of the thalamus.

What is the largest subcortical brain structure?

The largest subcortical brain structure of the basal ganglia is the striatum with a volume of approximately 10 cm.[1]Within the striatum, there are two main divisions, the dorsal striatum, and the ventral striatum. The dorsal striatum is primarily involved in control over conscious motor movements and executive functions, while the ventral striatum is responsible for limbic functions of reward and aversion.   Of the dorsal striatum, the caudate nucleus is a C-shaped structure comprising a head, body, and tail located lateral to the lateral ventricles. The lenticular (or “lens-shaped”) nuclei are bounded medially by the caudate and thalamus and laterally by the external capsule. The anterior end of the lenticular nuclei is continuous with the head of the caudate. The lenticular nuclei subdivide into the putamen and globus pallidus, which further divides into an external (GPe) and internal (GPi) segments. The striatum receives input signals from the cortex and limbic system and deep gain-setting nuclei of the brainstem (such as the substantia nigra, or SN). The dorsal striatum has GABAergic projections from medium spiny neurons onto either the GPi (called the “Direct pathway”) or the GPe (called the “Indirect pathway”) (See Figure). The ventral striatum is composed of the nucleus accumbens and the olfactory tubercle and has similar output pathways to the globus pallidus while receiving input from other gain-setting nuclei (such as the ventral tegmental area).

How do the intrinsic nuclei of the striatum communicate?

Finally, the intrinsic nuclei of the striatum communicate via the “Direct pathway” and “Indirect pathway” which are the classic elements of the intrinsic basal ganglia circuitry. These two pathways work in opposition to one another to allow for the weighing and choosing of motor movements.   Within the intrinsic nuclei of the dorsal striatum, there exist two main populations of neurons, neurons that are excited by dopamine and which express the D1-family of dopamine receptors, and neurons that are inhibited by dopamine and which express the D2-family of dopamine receptors.   The neurons that express the D1-family of receptors send projections to the GPi/SNpr to form the “Direct pathway ” while those expressing D2-family of receptors send projections to the GPe as part of the “Indirect pathway.”

Which pathway is responsible for the input of the caudate and putamen?

The corticostriate (and corticosubthalamic) pathways are cortical projections that input on the striatum, including the caudate and putamen.[3] These excitatory glutamatergic projections from layers III and V of the cortical lobes, including the motor, frontal, and parietal lobes provide the basal ganglia with information about conscious intentions to weigh with the deep, automatically triggered inputs from the SNpc which unconsciously constrain or enhance signals for certain outputs.   Because the basal ganglia nuclei or consistently somatotopically organized,[6]current thinking is that multiple input signals are required within the basal ganglia in order to “disinhibit” or “release” the functions that are receiving the most stimulatory and least inhibitory signals from the corticostriate and nigrostriatal pathways, as weighed by the basal ganglia. [7]

Basal Nuclei Function

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Functions of The Basal Ganglia

Pathways of The Basal Ganglia

Disorders of The Basal Ganglia

Significance of Basal Ganglia

• The basal ganglia – rather, the basal nuclei, if we want to get fancy – are incredibly important to numerous vital functions within the human nervous system. These clusters are what allow us to move, our hearts to beat, and part of what gives us the cognitive abilities that separate us from all non-human animal species on this earth. Their role in ...

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Introduction

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Structure

Basal Ganglia - Current Concepts

Pathophysiology

Physiotherapy - Implications from Recent Studies