Task 2

Question 1

Basal ganglia

Answer 1

large set of nuclei that lies within the cerebral hemispheres, includes caudate, putamen, globus pallidus, substantia nigra and the subthalamic nucleus (the first three being the motor components of the basal ganglia

Question 2

Corpus striatum

Answer 2

includes caudate and putamen with the internal capsule in between
 Input zone of the BG
 Destinations of incoming axons from the cerebral cortex and other parts of the brain (called medium spinal neurons, with large dendritic trees that can integrate various inputs)

Question 3

the main sources of output from the basal ganglia.

Answer 3

The globus pallidus (many myelinated axons) and substantia nigra pars reticulate (netlike structure)

Question 4

putamen input from

Answer 4

primary &secondary somatic sensory cortices (parietal lobe)
secondary visual cortices( occipital&temporal lobe)
auditory associations(temporal lobe)

neurons in it discharge in anticipation of limb & trunk movements => in movement selction process

Question 5

Medium spinal neurons

Answer 5

+integrate inputs from various cortical , thalamic & brain stem structures
+large dendretic structures
+axons arising here converge on neurons in pallidum
+ input from other sources than cortex
+when active, firing associated with occurence of movements
+gaba-ergic
+when active, firing associated with occurence of movement

Question 6

Cereberal cortex

Answer 6

+nearly all regions direct projection to corpus striatum

+largest Input source => especially association areas of frontal 6 parietal lobes

Question 7

Corticospainal pathway

Answer 7

+travels through the subcortical white matter to the caudate & putamen
+consists of multiple parrallel pathways with different functions=>different cortical regions project to different regions of striatum

Question 8

Corpus striatum

Answer 8

+in striatum visual & somatic sensory cortical projections
+functionally interconnected cortical areas => projections overlap extensively at striatum
the more extensively the areas are interconnected the more projections to striatum overlap

Question 9

direct pathway

Answer 9

Activation of medium spiny neurons in input nuclei (Caudate/Putamen) 
inhibition of neurons output nuclei (GPi) 
disinhibition of neurons in ventral thalamus (VA/VL)
• Neurons in striatum
and GP are
GABA-ergic
• Those in GP are
tonically active! 
tonic inhibition of
thalamic neurons.

Question 10

Direct pathway GO

Answer 10

D1

Question 11

Indirect pathway nO-go

Answer 11

D2

Question 12

Indirect pathway activation leads

to

Answer 12

excitation of STN  inhibition
of ‘surround’ region of GPi 
suppression of competing motor
programs at VA/VL level

Question 13

Direct pathway activation 

Answer 13

inhibition of ‘center’ GPi 
activation of intended motor
programs

Question 14

Motor circuit

Answer 14

Sensorimotor and premotor cortex

icludes STN, GPI, GPE PUT, THALAMUS

Question 15

Associative circuit

Answer 15

Dorsolateral prefrontal and lateral orbitofrontal cortex

Includes STN; GPi,GPe,Put,Cn,Thalamus

Question 16

Limbic circuit

Answer 16

limbic & paralimbic cortex, hippocampus & amygdala

Question 17

loops

Answer 17

Emotion / Motivation

• Cognitive
• Occulomotor
• Motor

Question 18

parkinson

Answer 18

Genetic and environmental factors:
loss of dopamine producing cells in
substantia nigra

Question 19

Parkinson treatment

Answer 19

Dopamine treatment (l-DOPA)
• Stem cells
• Deep brain stimulation