Basal Ganglia

Question 1

Basal Ganglia

Answer 1

Four interconnected subcortical nuclei, involved in voluntary movement, cognition and emotion

Question 2

Curvy thing

Answer 2

Caudate nucleus

Question 3

Go memorize the different images of coronal brain cuts

Question 4

Internal capsule separates…

Answer 4

Caudate from Putamen, globus pallidus

Question 5

Loop

Answer 5

Basal Ganglia-> Thalamus -> Cortex -> Basal ganglia - > thalamus -> cortex

Question 6

Caudal nucleus is…

Answer 6

very big in rostral section

Question 7

Whats right under/side of the internal capsule?

Answer 7

Putamen and globus pallidus

Question 8

Lateral walls of lateral ventricles…

Answer 8

Caudate nucleus

Question 9

Ventral anterior and ventral lateral nuclei

Answer 9

Specific relay nuclei that connect the cerebellum and basal ganglia w motor cortex

Question 10

Direct pathway of basal ganglia’s modulation of activity of thalamic neurons

Answer 10

Facilitates movement

Question 11

Indirect pathway of basal ganglia’s modulation of activity of thalamic neurons

Answer 11

Inhibits movement

Question 12

Putamen and Caudate nucleus

Answer 12

Inputs for Basal ganglia

Question 13

Caudate nucleus

Answer 13

Mostly involved in cognition

Question 14

Putamen

Answer 14

Mostly movement

Question 15

Thalamus to cortex? Inhibitory or excitatory?

Answer 15

Excitatory

Question 16

Cortex to putamen

Answer 16

Excitatory

Question 17

Almost all connections of basal ganglia are..

Answer 17

inhibitory

Question 18

Globus pallidus is…

Answer 18

Output structure of Basal Ganglia
There is internal and external segment
Internal segment is output back to the thalamus

Question 19

If you are not moving then the inhibitory neurons in the globus palidus internal segment…

Answer 19

Are firing like crazy
therefore less excitation of cortex

Question 20

Cortex excites neurons in putamen

Answer 20

Putamens inhibitory neurons inhibit the GP so now thalamus is not inhibited and can excited the cortex

Question 21

Indirect pathway

Answer 21

STN subthalamic nucleus neurons are excitatory and activate GP inhibitory firing which inhibits thalamus

Question 22

Substantia niagra

Answer 22

Dopamine neurons
Project to caudate nucleus and Putamen

Question 23

Dopamine effect on pathways

Answer 23

Excites direct pathway
Inhibits indirect pathway

Question 24

Action selection

Answer 24

Selecting appropriate movements
Inhibits incorrect movements

Question 25

Direct pathway could be on-signal Indirect pathway could be off-signal

Question 26

Hypokinetic disorders

Answer 26

Parkinson's Abnormal function of the basal ganglia Face lacks expression When they walk they take little shuffling steps Don't move very much

Question 27

Hyperkinetic disorders

Answer 27

Huntington's disease Flailing movements

Question 28

Parkinson's

Answer 28

Loss of dopaminergic input from substantia nigra Reduces activity in the direct pathway and accentuate activity in the indirect pathway

Question 29

Dopamine promotes activity of direct pathway so if dopamine is not working well...

Answer 29

The direct pathway will not inhibit GP and thalamus will be more inhibited by inhibitory neurons of GP Reduces activity in direct pathway Increases activity in indirect pathway

Question 30

L-dopa precursor helps...

Answer 30

Parkinson's

Question 31

Can try to lesion STN (subthalamic nucleus) for...

Answer 31

Parkinson's

Question 32

Huntington's disease

Answer 32

Reduced activity in the indirect pathway Direct pathway is intact Normal inhibition to thalamus is decreased resulting in excessive unwanted movements

Question 33

Tonic output from the basal ganglia inhibits neurons in the ...

Answer 33

Mesencephalic locomotion region (MLR) Cortical motor commands for walking cause relief of this inhibition MLR neurons activate decending medullary reticulospinal neurons which activate locomotion LCPattern Generators in the spinal cord

Question 34

Basal Ganglia comprises multiple parallel loops involved in

Answer 34

motor control eye movements motivation/emotion cognition

Question 35

Basal ganglia play a role in stimulus-response learning and the transformation of consciously-mediated, goal-directed responses into automated habits

Question 36

Difference between Substantia Nigra pars Reticulada (not dopamine) vs Globus pallidus internal

Answer 36

They are the same except separated by the internal capsule

Question 37

Saccade system - 4 steps

Answer 37

1) Frontal eye field fires excitatory neurons that excite Caudate 2) Caudate fires inhibitory neurons that inhibit substantia nigra reticular 3)Substantia nigra reticular is inhibited and therefore stops inhibiting the superior colliculus 4) Superior colliculus fires and results in saccades

Question 38

Lateral prefrontal cortex

Answer 38

Neurons in it fire suggesting they are holding the visual image in mind

Question 39

Baddeley and Hitch Model

Answer 39

Central executive --> Visuospatial sketch pad Phonological loop