Neuroscience Chapter on Basal Ganglia Movement

Structures in the brain that help select and initiate movements, inhibit unwanted movements, and control eye movements.

A set of instructions stored in the brain that tells the muscles how to move in a specific way.

A pathway that helps to initiate movements by activating neurons that control muscles.

A pathway that helps to inhibit unwanted movements by suppressing neurons that control muscles.

A group of neurons within the basal ganglia that receives input from the cortex and projects to other basal ganglia nuclei.

A group of neurons within the basal ganglia that receives input from the striatum and projects to the thalamus.

A nucleus in the basal ganglia that receives input from the globus pallidus and projects to the thalamus.

A brain structure that receives input from the basal ganglia and projects to the cortex, playing a role in motor control.

The basal ganglia act as a 'funnel and filter' for movement by receiving information from many cortical areas and only allowing movements appropriate for the current task to proceed.

BG neurons fire before a movement occurs, indicating a planning phase. Lesions in these areas can disrupt the initiation of movement.

At rest, the BG tonically inhibit the thalamus, preventing the initiation of movement. When movement is needed, this inhibition is relieved allowing movement to occur.

The thalamus, specifically certain thalamic nuclei, plays a critical role in stimulating the motor cortex. This stimulation allows for the execution of planned movement.

A brain region located medial to the putamen, with two distinct segments (GPi & GPe).

The most medial segment of the GP, responsible for outputting motor information through both the direct and indirect pathways.

The lateral segment of the GP, involved in modulating signals through projections to the subthalamic nucleus (only in the indirect pathway).

A group of nuclei within the basal ganglia that influence the activity of other nuclei, either by enhancing or inhibiting their signals.

A nucleus located inferior to the thalamus and involved in the indirect pathway. Receive inputs from the GPe and project to the GPi.

A midbrain nucleus alongside the crus cerebri, characterized by its dark appearance. Involved in both the direct and indirect pathways.

A pathway within the basal ganglia responsible for promoting movement by directly inhibiting the GPi and disinhibiting the thalamus.

A pathway within the basal ganglia responsible for inhibiting undesired movement, involving the GPe, subthalamic nucleus, and GPi.

The state of the GPi at rest, characterized by high levels of inhibitory activity, preventing the thalamus from exciting the cortex. This acts as a 'brake' on movement.

When the GPi is transiently inhibited by the striatum in the direct pathway, freeing the thalamus to stimulate the cortex and initiate movement.

The internal globus pallidus (GPi) is a nucleus in the basal ganglia that receives inhibitory input from the striatum and projects to the thalamus. It plays a key role in regulating movement by inhibiting thalamic activity.

The direct pathway is a neural circuit within the basal ganglia that facilitates movement. It involves a series of interconnected structures, including the striatum, globus pallidus internal segment (GPi), and thalamus. It is named "direct" as it has fewer synapses compared to the indirect pathway.

The substantia nigra (SN) is a brain region that plays a crucial role in movement control. It contains dopaminergic neurons that project to the striatum. The loss of dopaminergic neurons in the SN is a hallmark of Parkinson's disease.

The direct pathway is influenced by dopaminergic neurons from the substantia nigra (SN). Dopamine released from these neurons acts as an excitatory neurotransmitter on neurons in the striatum, enhancing the activation of the direct pathway and promoting movement initiation.

Parkinson's disease is a neurodegenerative disorder characterized by movement difficulties, such as slowness, rigidity, tremor, and postural instability. It primarily affects the substantia nigra (SN), leading to a loss of dopaminergic neurons and impaired function of the direct pathway.

The direct pathway within the basal ganglia is responsible for promoting movement initiation. It involves a series of interconnected structures, including the striatum, globus pallidus internal segment (GPi), and thalamus. The pathway operates by inhibiting the GPi, which in turn releases the thalamus from inhibition, allowing for the activation of the motor cortex and subsequent movement.

The direct pathway is a key component of the basal ganglia system involved in the control of voluntary movement. It functions by modulating the activity of the thalamus, which then projects to the motor cortex, ultimately influencing the execution of movement. The pathway is 'direct' because of its fewer synapses compared to the indirect pathway, suggesting a faster and more efficient signal transmission.

The caudate and putamen are two interconnected nuclei in the basal ganglia that receive input from the cerebral cortex and project to the globus pallidus. They are involved in planning and initiating movements.

The Globus Pallidus Internal segment (GPi) sends inhibitory signals to the Thalamus, suppressing movement in the indirect pathway.

The Subthalamic Nucleus (STN) excites the GPi in the indirect pathway.

The Globus Pallidus External segment (GPe) tonically inhibits the STN in the indirect pathway.

The Striatum inhibits the GPe in the indirect pathway, releasing the STN and allowing its excitatory signal to reach the GPi.

The indirect pathway helps to inhibit unwanted or competing movements by increasing inhibitory drive to the Thalamus.

The direct pathway activates desired movements, while the indirect pathway inhibits unwanted or competing movements.

Both pathways are essential for coordinating and controlling smooth, efficient movements.

The indirect pathway ultimately contributes to the inhibition of unwanted movement by increasing inhibitory drive to the Thalamus.

The Striatum, Subthalamic Nucleus, Globus Pallidus External, and Globus Pallidus Internal segments are key structures in the indirect pathway.

The indirect pathway prevents unwanted movements by increasing the inhibition of neurons controlling those movements in the Thalamus.

A movement disorder characterized by involuntary, jerky movements of the limbs, face, and trunk.

The striatum is a brain region involved in movement control. It's part of the basal ganglia, a group of structures important for movement initiation, execution, and learning.

The indirect pathway is a neural circuit in the basal ganglia that helps to inhibit unwanted movements. It's like a brake that prevents unnecessary movement.

The substantia nigra is a brain region that produces dopamine, a neurotransmitter crucial for movement control. It's involved in both the direct and indirect pathways.

Dopamine is a neurotransmitter that plays a vital role in movement control. It's associated with both excitation and inhibition of movement.

The globus pallidus is a brain region that receives input from the striatum and projects to the thalamus. It helps to control movement by modulating the thalamus.

The thalamus is a brain region that receives input from the globus pallidus and projects to the motor cortex. It helps to coordinate and relay movement information.

The subthalamic nucleus is a brain region that receives input from the globus pallidus and projects to the substantia nigra. It's involved in modulating movement by influencing the substantia nigra.

The basal ganglia helps to select and initiate movements, inhibit unwanted movements, and control eye movements. It's like a 'filter' that decides which movements are allowed.

The direct pathway is a neural circuit in the basal ganglia that helps to initiate movements. It's like an 'accelerator' that promotes movement.