basal ganglia

Question 1

what are the functions of the basal ganglia

Answer 1

Motor functions ( voluntary)
and non motor funcitons

Question 2

what are examples of the motor functions that the basal ganglia controls

Answer 2

 Action selection
 Inhibition of competing movements
 Enabling motor programs

Question 3

what are examples of non motor funcitons that the basal ganglia controls

Answer 3

 Cognition and emotion
 Reward and addiction

Question 4

what are the pathologies of the basal ganglia

Answer 4

( movment disorders) Hypokinetic
Hyperkinetic
-Cognitive and neuropsychiatric
symptoms

Question 5

what are the intputs to the motor cortex ( area 4)

Answer 5

 Thalamic nuclei VA & VL
 Premotor cortex (area 6)

Question 6

how can you see intergration in the motor cortex

Answer 6

• Cortex has subdivisions including the motor, sensory, and association cortexes.
• From the motor cortex, there are neurons that synapse to alpha motor neurons (blue)  aka the pyramidal tracts
• Basal ganglia receive inputs from all areas of the cortex
• Basal ganglia then projects to the thalamic motor nuclei, VA and VL
• VA and VL project to the motor cortex.

Question 7

what is the basal ganglia composed of

Answer 7

• globulis pallidus which is composed of the causdate and the putamen ( 1 nucleus)

Question 8

what is another term of the caudate and putamen?
globulus pallidus

Answer 8

• neostriatum
• paleostriatum

Question 9

what are the associated nuclei (midbrain)
- what are their recpriocal connections

Answer 9

• Substantia nigra
  >Reciprocally connected to
  caudateputamen
  > Dopaminergic projection to striatum
• Subthalamic nucleus
  > Reciprocally connected to globus
  pallidus

Question 10

where is the sbstantia nigra

Answer 10

Question 11

what is this

Answer 11

subthalmic nucleus

Question 12

what are the symptoms of parkinsons disease

Answer 12

 Tremor at rest (“pill rolling tremor”)
 Rigidity
 Bradykinesia ( walk slowly)
 Motor blocks (“freezing”)
 Loss of postural reflexes
 Cognitive defects are common

Question 13

what is parkinsons caused by

Answer 13

• due to loss of dopamine in th substantia nigra, degeneration of the substantia nigra

Question 14

what does someone with parkinsons look like

Answer 14

Question 15

what is the biosynthetic pathway of dopamine

Answer 15

syntheitc pathway stops at DOPA in the SN

Question 16

how can you treat parkinsons disease?
why cant you give dopamine

Answer 16

• take L dopa which is the precusor of dopamine
• bc of the blood brain barrier will not allow it to cross but L dopa can cross
• the SN then converts L dopa to dopmaine

Question 17

what is huntingtons chorea
- how does it present

Answer 17

 Degeneration in caudate nucleus
 Excess movements
 Autosomal dominant ( inhertied - 50% of offspring half a likely hood of getting it )

Question 18

what does huntingtons chorea eventually affect

Answer 18

• the prefrontal cortex
  the pt becomes degenerate

Question 19

when does huntingtons chorea present

Answer 19

• around 50 yo

Question 20

what is the huntigintons chorea the oppoiste of how should you not treat it

Answer 20

• parkinsons
• DONT TREAT WITH L DOPA

Question 21

what is ballismus
- how does it present

Answer 21

 Damage in subthalamic nucleus by stroke
> typically affects half the body
 Ballistic movements
- flinging movements fof limbs and tongue

Question 22

what is athetosis
- how does it present

Answer 22

 Excess movements
 Writhing (twisting) movements

Question 23

what are some other basal ganglia disorders

Answer 23

 Dystonia
 Tics
 Tourette syndrome

Question 24

what is the role of the basal in motor function

Answer 24

 suppresses inappropriate
motor program
 Activation of direct pathway
temporarily releases one motor
program from inhibition
 Also involved in learning of motor
programs

Question 25

what is the ventral tegmental area (VTA)

Answer 25

 Dopaminergic projections to
prefrontal cortex and limbic cortex
 Selection of emotional, executive and
cognitive programs
 Dopaminergic projection to nucleus
accumbens
 Reward and addiction

Question 26

where is the ventral tegemtnal area

Answer 26