Task 3

Question 1

What are the four principal structures of the basal ganglia?

Answer 1

striatum,
globus pallidus,
substantia nigra, and subthalamic nucleus

Question 2

What is the role of the ventral regions of the basal ganglia?

Answer 2

They play a key role in reward and reinforcement, important in the development of addictive behaviors and habit formation

Question 3

What cognitive functions are the central areas of the basal ganglia involved in?

Answer 3

They are involved in cognitive functions such as procedural learning and working memory tasks​

Question 4

How is the striatum divided?

Answer 4

The striatum is divided by the internal capsule into the caudate nucleus and putamen​

Question 5

What is the major role of the striatum in the basal ganglia?

Answer 5

It serves as the major input structure of the basal ganglia, receiving projections from the cerebral cortex, brain stem, and thalamus​

Question 6

What are the two pathways that axons from the striatum follow to the output nuclei?

Answer 6

They follow a direct monosynaptic connection and an indirect polysynaptic pathway​

Question 7

What is the most common neuronal cell type in the striatum, and what are its inputs?

Answer 7

1.The most common type is the GABAergic medium spiny neuron

2.receiving inputs from the cerebral cortex, thalamus, local interneurons, and dopaminergic neurons from the substantia nigra pars compacta and the ventral tegmental area

Question 8

What structures are included in the ventral striatum (VS)?

Answer 8

The VS includes:
the nucleus accumbens
medial & ventral portions of the caudate and putamen,

the striatal cells of the olfactory tubercle, and anterior perforated substance

Question 9

What are the three major sources of afferent projections to the striatum?

Answer 9

The cerebral cortex, thalamus, and brain stem dopaminergic cells

Question 10

What are the two segments of the globus pallidus, and what are their functions?

Answer 10

The external segment (GPe) is part of intrinsic circuitry, and the internal segment (GPi) is one of the major output structures of the basal ganglia​

Question 11

What are the major output structures of the basal ganglia, and where do they project?

Answer 11

The GPi and substantia nigra pars reticulata (SNr) are major output structures that project to the thalamus, which then projects back to the cortex​

Question 12

What are the two separate nuclei in the substantia nigra?

Answer 12

The pars compacta and pars reticulata

Question 13

What structures are included in the dopaminergic system?

Answer 13

The substantia nigra pars compacta (SNc), ventral tegmental area (VTA), and retrorubral group

Question 14

What are the functions of the direct and indirect pathways in the basal ganglia?

Answer 14

The direct pathway initiates movement by disinhibiting motor programs,

Indirect pathway serves as a brake on movement by disinhibiting basal ganglia outputs and suppressing downstream motor programs​

Question 15

What is the hyperdirect pathway in the basal ganglia?

Answer 15

It involves cortical inputs to the subthalamic nucleus and related subthalamopallidal projections

Question 16

What is the role of the cortico-basal ganglia-thalamocortical circuits?

Answer 16

These circuits develop and carry out complex behaviors, maintain and focus on execution of specific behaviors, and adapt to external and internal stimuli

Question 17

What are the general functional regions of the frontal cortex involved in?

Answer 17

Emotions and motivation (orbital and medial prefrontal cortex),
higher cognitive processes (dorsolateral prefrontal cortex),
motor planning (premotor areas),
and execution of motor plans (motor cortex)​

Question 18

Where do corticostriatal terminals primarily come from

Answer 18

They primarily come from:

layer 5
deep-layer-3

pyramidal neurons of the cerebral cortex

Question 19

How are cortical areas projected onto the striatum?

Answer 19

In a highly topographic manner, establishing functional domains replicated throughout the basal ganglia-thalamocortical circuits​

Question 20

What evidence supports functional integration between terminals from different cortical areas in the striatum?

Answer 20

regions of interface between terminals from different cortical areas converge at the dorsal-medial striatum​

where all the different systems in the basal ganglia converge

Question 21

What is the unique role of midbrain dopaminergic neurons in basal ganglia circuits?

Answer 21

They modulate a broad range of behaviors from learning and working memory to motor control and play a key role in the acquisition of new behaviors

Question 22

How are projections from the dorsal and ventral tiers of dopaminergic neurons organized?

Answer 22

The dorsal tier projects to the ventral striatum,

the ventral tier projects centrally and throughout different regions of the striatum​

Question 23

What is the significance of the striato-nigro-striatal projection system’s organization?

Answer 23

It demonstrates a loose topographic and functional organization that allows information from the limbic system to reach the motor system​

Question 24

How does the “ballot box” metaphor describe the striatum’s function?

Answer 24

It suggests that the striatum serves as a site where various sensory modalities, motivation networks, and cognitive systems “vote” for a limited set of behavioral responses​

Question 25

How do the direct and indirect pathways “vote” in the action selection process?

Answer 25

The direct pathway “votes for” a movement (Go), while the indirect pathway “votes against” a movement (No-Go)​

Question 26

What cognitive impairment is commonly associated with Parkinson’s disease?

Answer 26

A specific deficit in externally guided set shifting, which is uncontaminated by impairments in learning, working memory, or general cognitive slowing

Question 27

What role does the striatum play in decision making?

Answer 27

The striatum acts as a central arbiter for comparing the value of different choices and encodes values associated with actions and other task-relevant decision variables​

Question 28

How does the stability of value signals differ in the striatum?

Answer 28

The stability of value signals may differ in different subregions of the dorsal striatum​

Question 29

What is the significance of the cortico-striatal pathway in generating motor responses?

Answer 29

Activation of the cortico-striatal pathway is sufficient to bias choices,

integrating relevant information from a wide range of sources

Question 30

What are the three control processes involved in working memory?

Answer 30

Input control (selectively store information), output control (deploy subsets of information for behavior), and reallocation (eliminate obsolete representations)​