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Flashcards in N39 Deck (36)
1

Corpus striatum refers to

caudate + putamen + globus pallidus

2

Striatum refers to

caudate + putamen

3

Lenticular nucleus refers to

putamen + globus pallidus

4

nucleus accumbens

anterior area where caudate putamen are continuous centrally; related to limbic system and role in drug and alcohol addictions

5

Neurons in the striatum use what NTs

Ach or GABA

6

Globus pallidus neurons use what NT

GABA (inhibitory)

7

2 parts of globus pallidus

internal segment: projects to VA/VL thalamus (lenticular fasciculus and ansa lenticularis)
external segment: input from striatum and projects to internal segment and subthalamus

8

2 parts of substantia nigra

pars compacta and pars reticulata

9

Pars compacta of substantia nigra

Use dopamine and contain neruomelanin

10

Pars reticulata of substantia nigra

use GABA

11

Most inputs to basal ganglia are to

the striatum

12

Most outputs from basal ganglia are

from the GPi

13

Corticostriate

Cerebral cortex to ipsilateral striatum; excitatory and use glutamate

14

Within striatum there are 2 cell types

spiny neurons and cholinergic interneurons

15

Cholinergic interneurons

modulate local activity, activate neurons ACh-excitatory

16

Spiny neurons

require activation; GABA inhibition

17

Nigrostriatal

inputs use DOPAMINE via D1-D5 receptors (excitatory or inhibitory)

18

D1 and D5 when bound to dopamine exerts an

excitatory effect DIRECT PATHWAY

19

D2, D3, D4 when bound to dopamine exerts an

inhibitory effect INDIRECT PATHWAY

20

Straiatopallidal projections (GPe and GPi)

GABA pathways

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Striatonigral projections

GABA pathways

22

Subthalamic projections to GPi and pars reticulata uses

Glutamate

23

GPi outputs to

ansa lenticularis --> VA --> premotor cortex
lenticular fasciculus --> VL --> primary motor cortex

24

GPi outputs use what NT

GABA = inhibitory

25

Direct pathway

D1 receptor, excitatory, increases thalamic and cortical activity

26

Indirect pathway

D2 receptor, inhibitory, decreases thalamic and cortical activity (through the subthalamic nucleus)

27

Direct pathway

Corticostriate (+) --> activates inhibitory spiny neurons Striatopalladal (-) --> Palladothalamic (-) --> Thalamocortical (+) = Activation of LMN

28

Indirect Pathway

Corticostriate (+) --> activates inhibitory spiny neurons Striatopalladal (GPe) (-) --> Subthalamic nucleus (-) --> Subthalamic nucleus to GPi (+) --> palladothalamic (GPi) (-) --> thalamocortical are inhibited = Inactivation of LMN

29

Dopamine and the Direct pathway

excites the direct pathway (D1) by inhibiting inhibitory cells of the substantia nigra

30

Dopamine and the indirect pathway

inhibition in the indirect pathway (D2) by activation of inhibitory cells of the substantia nigra

31

Parkinsonism

indirect system dominates due to loss of dopaminergic input to striatum (ACh dominates)

32

ACh excites the Indirect pathway

leading to further activation of indirect pathway and decreased movement

33

ACh inhibits the direct pathway

leading to further decreased movement

34

Chorea

loss of cholinergic neurons, direct system dominates and excessive, unwanted movements occur

35

Basal Ganglia function

planning of voluntary movement and influence motor movements without a direct connection to LMN

36

Basal ganglia are connected with the limbic system and orbitofrontal cortex

memory, behavior changes, drug and alcohol addiction