BASAL GANGLIA

Question 1

What structures make up the basal ganglia?

Answer 1

-CAUDATE NUCLEUS
-PUTAMEN
-GLOBUS PALLIDUM (interna & externa)
-SUBTHALAMIC NUCLEUS
- SUBSTANTIA NIGRA

Caudate+Putamen=Striatum
Putamen+Pallidum= Lentiform nucleus

Question 2

What do the BBGG do?

Answer 2

• They are part of an Information Loop; taking information from the cortex, processing it & passing information back
• Mediate automatic activity (habitual control)
• A main role of the basal ganglia is the learning and selection of the most appropriate motor or behavioral programs

Question 3

SYSTEMS RELATED TO MOVEMENT

Answer 3

• Pyramidal system
• Basal ganglia
• Cerebellum (adjust movement)

Question 4

Main NT in basal ganglia

Answer 4

DOPAMINE
*LACK OF IT: NO MOVEMENT

Question 5

BBGG INPUT

Answer 5

Striatum (Caudate and Putamen)

Question 6

BBGG OUTPUT

Answer 6

Gpi (globus pallidus internus)

Proyects & INHIBIT the THALAMUS ( that connects through excitatory neurons to the Cortex)

Question 7

An increase

Answer 7

A decrease in thalamic & cortical activity

Question 8

BBGG DIRECT PATHWAY…

Answer 8

Promotes movement

STRIATUM INHIBITS Gpi, therefore activating the thalamus

Question 9

In relation to the BBGG direct pathway is correct to say:
- The GPe and the STN play an important role
- The net result of activity in this pathway is to excite the Gpi
- As a stop pathway , the net result of activity in this pathway is to stop movement
- Activity in this pathway inhibits the GPi

Answer 9

Activity in this pathway inhibits the GPi

Question 10

BBGG INDIRECT PATHWAY…

Answer 10

Is a STOP pathway.

Question 11

In the BBGG indirect pathway;
• a. there is an indirect link between the cortex and the thalamus
• b. there is an indirect link between the striatum and the GPi ( via GPe & STN)
• c. the net result of activity in this pathway is to inhibit the Gpi
• d. there is a direct link between the striatum and the GPi

Answer 11

there is an indirect link between the striatum and the GPi ( via GPe & STN)

Question 12

Hyperdirect pathway

Answer 12

STOP PATHWAY
Cortex stimulates STN which stimulate GPI which inhibits THALAMUS

Question 13

In the direct pathway we find … receptors

Answer 13

D1.
Dopamine activates them

Question 14

In the indirect pathway we find … receptors

Answer 14

D2
Dopamine inhibits them

Question 15

Dopamine decreases … activity, therefore promoting movement

Answer 15

GPI

Question 16

In relation to Dopamine and BBGG:
- The direct pathway has D2 dopamine receptors
- The indirect pathway has D2 dopamine receptors and when dopamine binds to them, the indirect pathway is activated
-The direct pathway has D1 dopamine receptors
- The overall efecto of dopamine is to promote GPi activity, therefore promoting movement

Answer 16

The direct pathway has D1 dopamine receptors

Question 17

Basal ganglia actions

Answer 17

They take part in different information loops that allow: VOLUNTARY MOTOR MOVEMENTS, eye movements, procedural learning, habit learning, cognition and emotion

Question 18

Parkinson’s disease is characterised by lack of …. neurons

Answer 18

Dopaminergic: which promote movement