Basal Ganglia

Question 1

what are the four major components of the basal ganglia?

Answer 1

1. striatum (caudate nucleus + putamen)
2. globus pallidus (GPe + GPi)
3. subthalamic nucleus
4. substantia nigra

Question 2

what is the lentiform nucleus?

Answer 2

putamen + globus pallidus

Question 3

how is the putamen seperated from the GPe?

Answer 3

from a white matter called lateral medullary lamina

Question 4

how is the GP seperated into the GPe and GPi?

Answer 4

by a white matter called medial medullary lamina

Question 5

where does the striatum get majority of its input and how is this shown?

Answer 5

it gets most of its input from the frontal lobe because the head of the caudate is in the frontal lobe and it is the largest part of the caudate

Question 6

what cerebral artery supplies most parts of the basal ganglia?

Answer 6

middle cerebral artery

Question 7

what are the functions of the basal ganglia?

Answer 7

• participate in control of voluntary movement via selection of motor plans: facilitate voluntary (desired) motor programs + supress unwanted (competing) motor programs
• modulate the functions of the pyramidal and extrapyramidal pathways, indirectly, by acting on SMC

Question 8

draw the cortical-basal ganglia-cortical loop : direct pathway.

Answer 8

see notes

Question 9

draw the cortical-basal ganglia-cortical loop : indirect pathway.

Answer 9

see notes

Question 10

draw the influence of SNC on direct pathways

Answer 10

see notes

Question 11

draw the influence of SNC on indirect pathways

Answer 11

see notes

Question 12

which neurotransmitters are GABA and are these inhibitory or excitatory?

Answer 12

striatum, GPe, GPi, SNr

inhibitory

Question 13

which neurotransmitters are glutamate and are these inhibitory or excitatory?

Answer 13

cortex, thalamus, STN

excitatory

Question 14

are D1 dopamine receptors excitatory or inhibitory?

Answer 14

excitatory

Question 15

are D2 dopamine receptors excitatory or inhibitory?

Answer 15

inhibitory

Question 16

is chorea huntington disease hyperkinetic or hypokinetic; what does this mean?

Answer 16

hyperkinetic = more movement

Question 17

is parkinsons disease hyperkinetic or hypokinetic; what does this mean?

Answer 17

hypokinetic = less movement

Question 18

what is huntingtons disease?

Answer 18

selective degeneration of striatum i.e. D2 receptor neurons. it reduces the activity of the indirect pathway = inability to suppress unwanted motor programs

Question 19

what is parkinsons disease?

Answer 19

degeneration of SNc; reduced activity of direct pathway = inability to initiated desired motor programs; increased activity of indirect pathway = increased suppression of motor programs