Peterson - Basal Nuclei Flashcards Preview

BECOM II Exam 5 > Peterson - Basal Nuclei > Flashcards

Flashcards in Peterson - Basal Nuclei Deck (15)
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1
Q

striatum

A
  • caudate nucleus
  • nucleus accumbens
  • putamen
2
Q

lenticular nucleus

A
  • putamen

- globus pallidus (external and internal segment)

3
Q

substantia nigra (dark segment)

A
  • compact - pigmented nuclei; dopaminergic regulation

- reticular - basal nuclei outputs

4
Q

general inputs and outputs

A

basal nuclei help control motor functions

  • excitatory input to striatum and subthalamic nuclei using glutamate
  • inhibitory output by internal globus pallidus and substantial nigra to thalamus using GABA
  • excitatory output from thalamus to cerebral cortex using glutamate
5
Q

striatum connections

A

job is to inhibit globus pallidus and substantia nigra when receiving excitatory inputs from cortex and thalamic nuclei and dopaminergic input from substantial nigra

6
Q

parallel loops

A

striatum receives different input

  • association cortex –> caudate nucleus
  • sensorimotor cortex –> putamen
  • limbic area –> nucleus accumbens
7
Q

connections to GPe

A
  • excitatory inputs from subthalamic nuclei

- inhibitory outputs to striatum, GPi, SNr, and STN

8
Q

connections to GPi and SNr

A
  • inhibited if receiving inputs from striatum
  • excited by STN to go on to inhibit thalamus
  • inhibitory effect to thalamus when activated
9
Q

connections to STN

A

excited by cortex –> excitatory outputs to GP and and SNr

-inhibited by GPe

10
Q

direct pathway

A

removes inhibition on thalamus

-striatum inhibits GPi –> remove inhibition on thalamus causing it to excite cortex

11
Q

indirect pathway

A

keep default inhibition on thalamus

-striatum inhibits GPe –> remove inhibition on STN causing excitation of GPi –> inhibit thalamus

12
Q

dopamine effects - indirect vs. direct

A
  • activator in direct path and inhibitor in indirect path
  • both paths increase muscle movement
    1. direct
  • dopamine binds to D1 activating inhibitory neuron –> inhibit GPi –> less inhibition on thalamus –> excite muscles
    2. indirect
  • dopamine binds to D2 inhibiting inhibitory neuron –> less inhibition on GPe –> inhibit STN –> less excitation of GPi –> less inhibition on thalamus –> excite muscle
13
Q

hemiballismus

A

uncontrolled movement of one arm and leg due to lesion in contralateral sub thalamic nuclei
-damage STN –> do not excite GPi –> more active thalamus

14
Q

Huntington’s

A

neural degeneration of striatum –> uncontrolled movements (chorea)

15
Q

Parkinson’s disease

A

reduce pigmentation of substantia nigra compacta –> reduce dopamine –> more inhibition on thalamus –> less muscle movement
-treat with L-dopa or unilateral pallidotomy