Chapter 16 Basal Ganglia

Question 1

basal ganglia function

Answer 1

goal-directed behavior, social behavior, and emotions, in addition to motor control
turn off motor programs that interfere with desired movements

Question 2

striatum

Answer 2

cuadate and putamen

Question 3

lentiform nucleus

Answer 3

globus pallidus and putamen

Question 4

Prosaccades

Answer 4

fast eye movements to direct attention toward an object
saccade: rapid eye movement
pro: towards an object

Question 5

antisaccades

Answer 5

fast movements away from an object
result of more complex interactions and require inhibition of prosaccade reflex

Question 6

Oculomotor Circuit

Answer 6

makes decisions about spatial attention and eye movements
determining whether to use fast eye movements to direct attention toward an object
body of caudate

Question 7

Motor Circuit

Answer 7

regulates skeletal muscle contraction, muscle force, multijoint movements, and sequencing of movements
includes: cerebral cortex motor areas, substantia nigra compacta, putamen, EPG, IPG, subthalamic nucleus and motor thalamus

Question 8

disinhibition

Answer 8

occurs when another neuron inhibits the inhibitory neuron, allowing increasing activity in the target neuron

Question 9

There is no direct communication between

Answer 9

Basal Ganglia and LMN
Cerebellum and LMN

Question 10

Stop, Go, and No-Go Pathways

Answer 10

all happen at the same time
normal movement requires all 3 of them

Question 11

Stop Pathway (Hyperdirect)

Answer 11

suppression of voluntary movement (stop drinking)
powerful inhibition of motor thalamus
Fastest Pathway
Cerebral Cortex → excites STN → STN excites IGP → IGP inhibits motor thalamus

Question 12

Go Pathway (Direct)

Answer 12

facilitates specific movements (reach for cookie)
Substantia Nigra D1 → Putamen → inhibits IGP → IGP inhibits motor thalamus → motor thalamus excites motor areas of cortex

Question 13

No-Go Pathway (Indirect)

Answer 13

suppression of unwanted movements (do not abduct shoulder)
Substantia Nigra D2 → Putamen → inhibit EGP → EGP inhibits STN →STN excites IGP → IGP inhibits motor thalamus

Question 14

Neurotransmitters of the 3 pathways

Answer 14

Glutamate is excitatory
GABA is inhibitory

(Acetylcholine is excitatory)

Question 15

Substantia Nigra supplies motor circuit with

Answer 15

Dopamine
D1 is excitatory (excites inhibitory neurons in Go)
D2 is inhibitory (inhibits neurons from putamen)

Question 16

Voluntary muscle activity via

Answer 16

IGP →Motor Thalamus uses Glu to corticospinal tracts

Question 17

Postural and girdle muscle activity via

Answer 17

IGP →Pedunculopontine Nucleus (PPN) uses GABA via reticulospinal tracts

Question 18

Walking via

Answer 18

IGP →Midbrain locomotor region (MLR) uses ACh via reticulospinal tracts

Question 19

Hypokinetic Disorders

Answer 19

too little movement
Parkinson’s
Secondary Parkinson’s

Question 20

Hyperkinetic Disorder

Answer 20

excessive movement
Huntington’s
Dystonia
Tourette’s
Dyskinetic CP

Question 21

Parkinson’s Disease

Answer 21

most common
affects voluntary and automatic movements
affecting upper body with rigidity and/or resting tremor
2 types: Postural Instability Gait Difficulty PIGD
and Tremor Dominant (akinetic/rigid type)
can shift from one to another

Question 22

Postural Instability Gait Difficulty PIGD

Answer 22

Rigidity of trunk, freezing of gait FOG, resting tremor/action tremor, dementia, orthostatic hypotension, constipation, festinating gait (body leans forward and takes very small steps), falling is big risk, retropulsion (pushing back on chair when standing up leads to falling), akinesia/hypokinesia/bradykinesia

Question 23

Akinesia

Answer 23

the absence of movement

Question 24

Hypokinesia

Answer 24

loss of automatic movements, including facial expression and normal arm swing during walking

Question 25

Bradykinesia

Answer 25

slowness of movement

Question 26

Rigidity

Answer 26

increased resistance to movement in both flexor and extensor muscles

Question 27

Cogwheel rigidity

Answer 27

rigidity experienced by people with Parkinson's move joint passively through its range, the motion catches and releases as if the joint contained a cogwheel and lever

Question 28

Freezing of gait (FOG)

Answer 28

movement abruptly stops due to visual block doorway or chair

Question 29

Resting Tremor

Answer 29

involuntary, rhythmic shaking movements of the limbs produced by contractions of antagonist muscles 4-6 tremors per second

Question 30

Action Tremor

Answer 30

involuntary, rhythmic shaking during voluntary movement due to cerebellar dysfunction or parkinson's faster, 5-8 tremors per second

Question 31

Parkinson's dementia

Answer 31

social impairment, emotional/motivation impairment, and autonomic dysfunction. deterioration of intellectual function interferes with ability to plan, maintain goal direction, and make decisions

Question 32

Apathy

Answer 32

loss of interest, emotion, and motivation

Question 33

Pathology in Parkinson's

Answer 33

death of DA-producing cells in the substantia nigra compacta and GABA producing cells in the PPN

Question 34

Treatments for Parkinson's

Answer 34

drug therapy that replaces DA with Ldopa OT, PT, moderate-high intensity cardio Invasive procedures : deep brain stimulation, destructive surgery (Thalamotomy and Pallidotomy), neuronal transplant LSVT BIG

Question 35

Secondary Parkinsonism

Answer 35

symptoms that mimic Parkinsons origin is due to trauma, toxic, infections, drugs lesions of lentiform nucleus

Question 36

Chronic Traumatic Encephalopathy

Answer 36

type of secondary parkinsonism Parkinson-like signs, disordered thinking, depression, memory loss, dysfunction of goal-directed behavior, and disinhibition requires history of head trauma

Question 37

Huntington's Disease

Answer 37

chorea/athetosis and dementia, progressive fatal hereditary disease, excess number of repeats affecting 3 DNA building blocks in Huntington gene, results in protein with excess number of glutamine units move frequently and forcefully in sleep goal directed and emotions affected with apathy and depression no treatments

Question 38

Chorea

Answer 38

involuntary jerky rapid movements

Question 39

athetosis

Answer 39

slow, squirming, purposeless movements

Question 40

Dystonia

Answer 40

involuntary sustained muscle contractions that cause abnormal postures or twisting and/or repetitive movements + tremor increases during activity and emotional stress, goes away with sleep genetic and nonprogressive

Question 41

Focal Dystonia

Answer 41

most common type, limited to one part of the body ex. spasmodic torticollis

Question 42

Torticollis

Answer 42

involuntary, asymmetric contraction of neck muscles causing abnormal position of the head

Question 43

Generalized dystonia

Answer 43

causes involuntary twisting postures of the limbs and trunk begins with inversion and plantarflexion of the foot while walking often progressive

Question 44

Tourette's Disorder

Answer 44

causes vocal and motor tics abrupt, repetitive, stereotyped movements stress, emotional excitement, and fatigue exacerbate tics

Question 45

Dyskinetic CP

Answer 45

muscle tone and posture are abnormal and involuntary movements occur Dystonia causes abnormal posture involuntary movements are choreoathetosis