Basal Ganglia

Question 1

List the main components of the basal ganglia.

Answer 1

Striatum - Caudate ad Putamen
Globus Pallidus - External and Internal
Sub Thalamic Nucleus
Substantia Nigra - Pars Compacta Pars Reticulata

Question 2

The direct pathway of the Basal Ganglia is intrinsic in what?

Answer 2

The initiation of movement

Question 3

The first step in the direct pathway is what?

Answer 3

The cerebral cortex releases glutamate into the striatum..

Question 4

An activated striatum does what?

Direct Pathway

Answer 4

Releases GABA

Inhibits the Globus Pallidus Interna and Substantia Nigra Pars Reticula.

Question 5

What is the function of an uninhibited Globus Pallidus Internal and substantia nigra pars reticula?
Direct Pathway

Answer 5

Release GABA into the thalamus suppressing movement.

Question 6

As a result of GABA being released into the Globus Pallidus Interna and Substantia Nigra Pars Reticula what happens.
Direct Pathway

Answer 6

The two components are inhibited so less GABA is released in to the thalamus so it is activated.

Question 7

An uninhibited thalamus does what?

Direct Pathway

Answer 7

Release Excitatory Glutamate to initiate movement.

Question 8

What is the function of the Substantia Nigra Pars Compacta.

Answer 8

Modulates the indirect system - antagonist to the direct.

Question 9

Draw the Direct Basal Ganglia Pathway

Answer 9

.

Question 10

What does the SN Pars Compacta release into the striatum.

Answer 10

Dopamine

Question 11

Indirect Pathway

The release of dopamine from where into the striatum does what?

Answer 11

SN Pars Compacta

Increases the release of GABA.

Question 12

Indirect Pathway.

Release of GABA into the where results in no inhibition of the Subthalamic Nuclei

Answer 12

GABA released from Striatum means that the Globus Pallidus Externa is inhibited so can’t release inhibitory GABA into the Subthalamic nuclei.

Question 13

As a result of the activation of the striatum by dopamine release what happens directly between the cerebral cortex and the sub thalamic nuclei?
Indirect Pathway

Answer 13

Cerebral Cortex excites the Subthalamic nuclei which excite the GABA neurones in the Globus Pallidus Interna and the Substantia Nigra Reticula.

Question 14

Activation of the GABA neurones in the Substantia NIgra Reticula and the Globus Pallidus Interna does what?
Indirect Pathway

Answer 14

Inhibition of the thalamus

Inhibits Movement

Question 15

Loss if the Substantia Nigra results in what disease and why?

Answer 15

Parkinsons - unable to inhibit movement.