2.29 Basal Ganglia Pathways Flashcards Preview

7303 Neuroanatomy > 2.29 Basal Ganglia Pathways > Flashcards

Flashcards in 2.29 Basal Ganglia Pathways Deck (35):
1

two basal ganglia pathways

- direct
- indirect

2

basal ganglia pathways are modulated by this NT

dopamine

3

How do the direct/indirect pathways work overall?

- antagonistic to one another: both working constantly
- balance help produce smooth movements

4

What type of NT does the striatum use?

inhibitory NT

5

Direct pathway allows _______. Indirect pathway _______ to allow for _______ _______.

- movement
- modulates
- smooth movements

6

outcome of direct pathway activation

activation increases movement

7

At rest, the direct pathway is ______

inactive

8

Which two things send GABA-ergic input to the thalamus in the direct pathway (at rest)

- GPi
- SNpr

9

What does the motor thalamus do normally?

excites motor cortex to initiate movement

10

What is the result of GABAergic input to thalamus?

- inhibits the thalamus before it can project to the motor cortex

= less movement

11

direct pathway is _____ at play

active

12

motor planning region projects to

striatum

13

striatum projects to

GPi + SNpr » thalamus » motor cortex

14

Why is the direct pathway active at play?

- cannot inhibit the thalamus
- just because there's disinhibition, doesn't go to zero

15

movement is ______ in the direct pathway at play

increased

16

disruption of direct pathway leads to ________ (decreased movement)

hypokinesia

17

indirect pathway outcome

activation decreases movement

18

indirect pathway at rest: outcome

movement increases

19

indirect pathway at play: outcome

movement decreases

20

disruption of indirect pathway leads to __________ (increased movement)

hyperkinesia

21

Where does dopamine come from (specifically)?

SNpc

22

What type of neurons does dopamine stimulate?

GABAergic

23

dopamine signaling favors movement via _______ _______

direct pathway

24

two types of dopamine receptors

D1 receptor
D2 receptor

25

D1 receptor

- increases activity of direct pathway
- this is how SNpc has widespread modulation

26

D2 receptor

decreases activity of indirect pathway

27

The dopamine pathway ______ movement

increases

28

Huntington's

- GABAergic neurons in striatum die: get hyperkinesia
- nothing left to run the indirect pathway
- get major movements all the time

29

basal ganglia pathways: motor cortex

- lateral corticospinal tract (contralateral)
- rubrospinal tract

30

lateral corticospinal tract

- distal limb
- fractionate movement

31

rubrospinal tract

allows for extension of wrist/fingers (UE)

32

basal ganglia pathways: GPi

- VLPP
- midbrain (reticular formation)

33

VLPP

ventrolateral pedunculopontine

34

reticulospinal

- via the VLPP, the reticulospinal tract allows for postural adjustments
- where you get your stepping pattern generators

35

midbrain (reticular formation)

reticulospinal tract
- stepping pattern generation