Basal Ganglia

Question 1

Medial Surface of Brain

Answer 1

Question 2

Ventricles of Brain

Answer 2

Question 3

Basal Ganglia Schematic

Answer 3

Question 4

Basal Ganglia Cortical links

Answer 4

Question 5

The striatum receives massive inputs from large regions of the ____________

Answer 5

Cerebral cortex, the centro medial parafascicular nuclear complex, the substantia nigra, all of the mesencephalic nuclei and the lateral amygdala

Question 6

The projections to the pallidum arise mainly from the _____________ and from the _________

Answer 6

Caudate Nucleus

Putamen

Question 7

What two main diseases concern the basal ganglia with a lack of neurotransmitter?

Answer 7

Parkinson and Huntington

Question 8

What makes up the basal ganlia (basal nuclei)?

Answer 8

a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit.

Question 9

Where are the basal ganglia located? What are they “connected” to?

Answer 9

They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus, and other brain areas.

Question 10

The basal ganglia are associated with a variety of functions, including……

Answer 10

voluntary motor control, procedural learning relating to routine behaviors or “habits” such as bruxism, eye movements, cognitive and emotional functions.

Question 11

Current popular theory of use

Answer 11

Currently popular theories implicate the basal ganglia primarily in action selection, that is, the decision of which of several possible behaviors to execute at a given time

Question 12

Experimental studies show that the basal ganglia exert an _______ influence on a number of _______, and that a release of this _____ permits a _______ 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 _________, which plays a key role in __________

Answer 12

inhibitory

motor systems

inhibition

motor system

prefrontal cortex

executive functions

Question 13

The main components of the basal ganglia are the……

Answer 13

striatum (caudate nucleus and putamen), the globus pallidus, the substantia nigra, the nucleus accumbens, and the subthalamic nucleus

Question 14

The largest component of the basal ganglia

Answer 14

Striatum

Question 15

The striatum, receives input from ________ but sends output only to ________

Answer 15

many brain areas

other components of the basal ganglia

Question 16

The pallidum receives input from the ________ and sends inhibitory output to _______________.

Answer 16

striatum

a number of motor-related areas

Question 17

The substantia nigra is the source of the _______ input of the neurotransmitter __________, which plays an important role in basal ganglia function.

Answer 17

striatal

dopamine

Question 18

The subthalamic nucleus receives input mainly from the ________ and ________, and projects to the __________

Answer 18

striatum and cerebral cortex

globus pallidus.

Question 19

Parkinson’s disease involves degeneration of the __________-producing cells in the ___________

Answer 19

dopamine

substantia nigra pars compacta

Question 20

Huntington’s disease, primarily involves damage to the ______

Answer 20

striatum.

Question 21

Basal ganglia dysfunction is also implicated in some other disorders of behavior control such as:

Answer 21

Tourette syndrome, hemiballismus, obsessive–compulsive disorder, and Wilson’s disease.

Question 22

The basal ganglia have a limbic sector whose components are assigned distinct names:

Answer 22

the nucleus accumbens, ventral pallidum, and ventral tegmental area.

Question 23

There is considerable evidence that the limbic sector of basal ganglia plays a central role in ________, particularly a pathway from the ___________ to the _________ that uses the neurotransmitter ______

Answer 23

reward learning

ventral tegmental area

nucleus accumbens

dopamine

Question 24

A number of highly addictive drugs, including cocaine, amphetamine, and nicotine, are thought to work by increasing the ______ of dopamine signal.

Answer 24

efficacy

Question 25

The basal ganglia are a collection of distinct masses of _____ matter lying deep in the brain not far from the junction of the \_\_\_\_\_\_

Answer 25

gray thalamus.

Question 26

What does "striatum" mean

Answer 26

striped

Question 27

What two parts seperated by the internal capsule make up the striatum?

Answer 27

Caudate nucleous Putamen

Question 28

The pallidum consists of a large structure called the ________ together with a smaller ventral extension called the \_\_\_\_\_\_

Answer 28

globus pallidus ("pale globe") ventral pallidum.

Question 29

Globus pallidus has two functionally distinct parts called \_\_\_\_\_\_\_\_\_\_\_\_

Answer 29

the internal (or medial) and external (lateral) segments, abbreviated GPi and GPe.

Question 30

Pallidum contain primarily ________ neurons, which therefore have ______ effects on their targets

Answer 30

GABAergic inhibitory

Question 31

Pallidal neurons operate using a disinhibition principle. This statment means that......

Answer 31

These neurons fire at steady high rates in the absence of input, and signals from the striatum cause them to pause or reduce their rate of firing.

Question 32

the net effect of striatal input to the pallidum is a _______ of the tonic inhibition exerted by pallidal cells on their targets (disinhibition) with an ______ rate of firing in the targets.

Answer 32

reduction increased

Question 33

The substantia nigra is a mesencephalic ____ matter portion of the basal ganglia that is divided into _______ and \_\_\_\_\_\_\_\_

Answer 33

gray SNr (reticulata) SNc (compacta).

Question 34

SNr often works in unison with GPi, and the SNr-GPi complex _______ the \_\_\_\_\_\_

Answer 34

inhibits thalamus.

Question 35

Substantia nigra pars compacta (SNc), produces the neurotransmitter \_\_\_\_\_\_, which is very significant in maintaining balance in the striatal pathway

Answer 35

dopamine

Question 36

The substantia nigra is \_\_\_\_\_\_\_cephalic

Answer 36

mesencephalic

Question 37

The subthalamic nucleus (STN) is \_\_\_\_cephalic

Answer 37

diencephalic

Question 38

The only portion of the ganglia that actually produces an excitatory neurotransmitter is....... The neurotransmitter is.......

Answer 38

The subthalamic nucleus (STN) glutamate

Question 39

The role of the subthalamic nucleus is to...... and it is part of the _____ pathway

Answer 39

stimulate the SNr-GPi complex and it is part of the indirect pathway.

Question 40

Describe the antagonistic functions of the direct and indirect pathways of the ganglia

Answer 40

The antagonistic functions of the direct and indirect pathways are modulated by the substantia nigra pars compacta (SNc), which produces dopamine. In the presence of dopamine, D1-receptors in the basal ganglia stimulate the GABAergic neurons, favoring the direct pathway, and thus increasing movement.The GABAergic neurons of the indirect pathway are stimulated by excitatory neurotransmitters acetylcholine and glutamate. This sets off the indirect pathway that ultimately results in inhibition of upper motor neurons, and less movement. In the presence of dopamine, D2-receptors in the basal ganglia inhibit these GABAergic neurons, which reduces the indirect pathways inhibitory effect. Dopamine therefore increases the excitatory effect of the direct pathway (causing movement) and reduces the inhibitory effect of the indirect pathway (preventing full inhibition of movement). Through these mechanisms the body is able to maintain balance between excitation and inhibition of motion. Lack of balance in this delicate system leads to pathologies such as Parkinson's disease. Parkinson's disease involves the loss of dopamine which means the direct pathway is less able to function (so no movement is initiated) and the indirect pathway is in overdrive (causing too much inhibition of movement).

Question 41

\_\_\_\_\_\_\_\_ disease involves massive loss of medium spiny neurons in the striatum

Answer 41

Huntington's

Question 42

\_\_\_\_\_\_\_\_ disease involves major loss of dopaminergic cells in the substantia nigra

Answer 42

Parkinson's

Question 43

\_\_\_\_\_\_\_may result from damage restricted to the subthalamic nucleus. _________ is characterized by violent and uncontrollable flinging movements of the arms and legs.

Answer 43

Hemiballismus Hemiballismus