Basal Ganglia Flashcards
What Basal nuclei are apart of the: Dorsal Basal Nucleus
Caudate Nucleus
Putamen
Globus Pallidus
What Basal nuclei are apart of the: Ventral Striatum
Nucleus Acumbens
Olfacatory Nucleus
What Basal nuclei are apart of the: Ventral Palladium
Substantia Innominata
What Basal nuclei are apart of the: Striatum
Caudate nucleus
Putamen
What Basal nuclei are apart of the: Paleostriatum
Globus pallidus
What Basal nuclei are apart of the: Lenticular Nucleus
Putamen
Globus Pallidus
What Basal nuclei are apart of the: Striatal Complex
Caudate Nuceus
Putamen
Nucleus Accumbens
Olfactory Tubercle
What Basal nuclei are apart of the: Palladial Complex
globus pallidus
substantia Innominata
What are the parts of the globus pallidus
Internus
Externus
What are the parts of the substantia nigra
Pars Compacta (superior) Pars reticulata (inferior)
Parallel Circuts: Cortex, Input, output, relay, and role: Skeletomotorloop
Cortex: Primary motor, supplementary motor, premotor cortex
Input: Putamen
Output: Globus pallidus internus
Substantia nigra pars reticulata
relay: Ventral anterior
Ventral lateral nucleus of the thalamus
role: in the control of facial, limb, and trunk musculature
Parallel Circuts: Cortex, Input, output, relay, and role: Oculomotor loop
Cortex: Frontal eye field, supplementary eye field
input: Caudate (body)
output: Substantia nigra pars reticulata
Globus pallidus internus
Relay: Ventral anterior nucleus
medial dorsal nucleus
role: in control of saccadic eye movement
- putting the object of interest on the fovea
Parallel Circuts: Cortex, Input, output, relay, and role: Associative loop
Cortex: Prefrontal, premotor
input: Caaudate (body)
output: Substantia nigra pars reticulata
Globus pallidus internus
relay: Ventral anterior
medial dorsal
role: in cognition and executive behavioral functions
Parallel Circuts: Cortex, Input, output, relay, and role: Limbic loop
cortex: Anterior cingulate gyrus
orbitofrontal cortex
input: ventral striatum
output: Ventral pallidum (Globus pallidus internus, substantia nigra pars reticulata)
relay: Medial dorsal
ventral anterior
role: Participates in the motivational regulation of behavior and in emotions
Direct pathway (skeletalmotor loop)
Cortex sends excitatory glutamate to the striatum (putamen/caudate)
striatum sends inhibitory GABA/substance P to the globus pallidus internus or the substantia nigra pars reticulata
then from their they send inhibitory GABA to the thalamus specifically the VA and the VL
Then thalamus will send Excitatory information back to the supplementary to the supplementary motor area
(note: a feedback loop also occurs where the substantia nigra pars compacta will send Dopamine to inhibit/excite the striatum to further enhance or inhibit the loop)
Indirect pathway (skeletalmotor loop)
Cortex sends excitatory Glutamate down to the striatum
Striatum will release inhibitory GABA/enkephalin on to the globus pallidus external segment
the globus pallidus externus will send inhibitory GABA on to the subthalamic nucleus
the subthalamic nucleus will then send Excitatory glutamate to the globus pallidus internus/ substantia nigra pars reticulata
this will then send inhibitory GABA on to the thalamus specifically the VA and VL which will send excitatory on to the supplementary motor area
(note: a feedback loop also occurs where the substantia nigra pars compacta will send Dopamine to inhibit/excite the striatum to further enhance or inhibit the loop)
Parkinsons disease
Loss of the substantia nigra and loss of the release of Dopamine
progressive starting at age of 60
Triad:
Tremor: pill rolling
Rigidity: cogwheel rigidity (resting tremor and rigidity)
Bradykinesia: toughtime moving
also can see hypokinesia, postral instabillity, dimentia, and visuperceptive impairments
can affect walking, speech and facial expressions
Treatment:
Drugs to increase dopamine levels, through adding dopamine or preventing its breakdown
Causes of Parkinsonian syndrome
idiopathic parkinson disease
Encephalitis lethargica
Head trauma- dementia pugilistica
MPTP - designer drug that causes symptoms
Carbon monoxide and mangenese poisioning
Drug induced via neuroleptics: dopamine blocking drugs
wilson disease- heptaolenticular degeneration
rigidity plus other deficits in multiple neurodegenerative diseases
Huntingtons Chorea
Degeneration of neurons in striatum leading to decreased GABA
Huntingtons disease
Progressive disease with onset at average age of 45
Autosomal dominant
-HTT gene mutation leading to CAG trinucleotide repeats
involuntary, jerky, and rapid movements
dimentia
Unsteady gait, slurred speech, trouble maintaining tong protrusion, irregular breathing
Depression
Huntington disease treatments
Tetrabenazine (serotonin antagonist) Typical antipsychotic (antagonize dopamine) Reserpine, tetrabnazine (depleting dopamine)
Ballismus
Flailing, flinging movement of the whole extremity seen in lesions of the contralateral subthalamic nucleus
can be related to stroke, inflammation. or tumor
Chorea
spontaneous rapid, jerkey, arrhythmic and involuntary movements which are purposeless or fragments of motor programs
Acute Rheumatic Fever
woman experienced acute rheumatic fever as a chile and it has developed into rhematic heart disease after heart valve damage
Arthiritis heart inflammation nodules subcutaneously erythema marginatum sydenhams chorea
Athetosis
inabillity to sustain the body part in one position, movements are writhing or snake like, often seen whith chorea (choreoathetosis)
slow writhing, continuous movements
can be seen in combination with other disorders
seen with dopamine blocking drugs or hypoxic ischemic injury
Writers cramp (focal dystonia)
persistance or fixing of the posture at the extreme of an athetoid movement of either the extremities or the trunk
non painful but can severly affect abillity to write
involuntary, sustained muscle contracture of extensors and or flexors of the hand
Other types of dystonia
Torticollis (cervical dystonia)
Blepharospasm
Drug induced
