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Exam 4 - Section 3
Basal Ganglia
44
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Undergraduate 3
11/19/2015

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Term
The basal ganglia receives input from the ______, including sensory, motor, & associative areas
Definition
entire cortical mantle
Term
The basal ganglia feeds back through the ventral anterior & ventral lateral thalamic nuclei primarily to the ______
Definition
prefrontal/premotor cortices
Term
The principle function of the basal ganglia is to provide a mechanism for the ______ for planning & initiating movement
Definition
selection of adaptive motor programs
Term
The ______ & ______ are part of the same structure, even though they were discovered separately & are divided by the fibers of the internal capsule
Definition
GPi & SNr
Term
The GPi & SNr are ______ organized, with the GPi regulating movements of the trunk & limbs & the SNr regulating head & eye movements
Definition
somatotopically
Term
The projection of the cortical mantle to the striatum is topographically organized, creating multiple functional loops running ______
Definition
in parallel
Term
The ______ loop runs from frontal/parietal cortex to the putamen & operates in fine motor control
Definition
sensorimotor
Term
The ______ loop runs from prefrontal cortex & other association areas to the caudate & operates in cognitive function
Definition
associative
Term
The _____ loop runs from the frontal/temporal lobes to the ventral striatum & contributes to motivated behaviors
Definition
limbic
Term
The ______ loop is activation of the glutamate corticostriatal pathway & affects two GABA neurons in series, leading to disinhibition of thalamocortical drive to the prefronal/premotor areas
Definition
simple
Term
In the direct pathway, striatal GABA neurons that contain ______ project to the GPi/SNr
Definition
substance P
Term
Cortical activation of the direct pathway results in ______ of thalamocortical drive
Definition
disinhibition
Term
In the indirect pathway, striatal GABA neurons that contain ______ project to GABA neurons in the GPe, which in turn project to the subthalamic nucleus
Definition
enkephalin
Term
In the indirect pathway, glutamate neurons in the subthalamic nucleus in turn project to the GABA neurons in the ______
Definition
GPi/SNr
Term
Cortical activation of the indirect pathway leads to ______ of thalamocortical drive, an action that opposes the direct pathway
Definition
inhibition
Term
The main cell type in the striatum is the ______
Definition
medium spiny neuron
Term
Corticostriatal inputs synapse onto the heads of medium spiny neuron ______
Definition
spines
Term
Dopamine projections from the ______ synapse onto the necks of the medium spiny neuron spines or close by on the dendritic shaft
Definition
substantia nigra compacta
Term
Dopamine is in a critical position to ______ corticostriatal transmission
Definition
modulate
Term
Dopamine ______ corticostriatal transmission in the direct pathway via a D1 receptor & _____ corticostriatal transmission in the indirect pathway via a D2 receptor
Definition
facilitates; attenuates
Term
The net effect of dopamine is to facilitate ______ drive through the direct pathway
Definition
thalamocortical
Term
In ______, loss of dopamine's modulatory influence means that transmission through the direct pathway is blunted, while transmission through the indirect pathway is heightened
Definition
Parkinson's disease
Term
The end result of Parkinson's is excessive inhibition of thalamocortical drive, which may explain the ______ symptoms
Definition
hypokinetic
Term
Parkinson's Disease is associated with loss of neurons in the brainstem, most significantly ______ in the midbrain
Definition
pigmented dopamine neurons
Term
The cause of Parkinson's is unknown (_____), but sometimes results from head trauma, viral encephalitis, environmental neurotoxins
Definition
idiopathic
Term
Parkinson-like symptoms can result from ______ that block dopamine receptors
Definition
antipsychotic medications
Term
The main symptom of Parkinson's is ______ (difficulty in the initiation of movement & lack of spontaneous movements)
Definition
hypokinesia
Term
In Parkinson's, movements exhibit ______ (slow execution)
Definition
bradykinesia
Term
The best-known symptom of Parkinson's is ______ (no other neurological condition causes a tremor that is seen only at rest & is alleviated by purposeful movement)
Definition
resting tremor
Term
Parkinson's patients manifest ______ or increased muscle tone in the limbs & postural instability that makes them susceptible to falls
Definition
rigidity
Term
Descending cortical transmission is impoverished but not abolished in Parkinson's Disease, as ______ & ______ appear to be of cortical origin
Definition
tremor & rigidity
Term
Parkinson's patients can overcome hypokinesia when provided sufficient sensory stimuli (______) suggesting that the basal ganglia may be most important for regulating spontaneous movements rather than sensory-evoked movements
Definition
paradoxical kinesia
Term
Parkinson's Disease is treated by the precursor, ______, which is converted in the brain to dopamine
Definition
L-DOPA
Term
Drug therapy for Parkinson's does not stop the disease progression, sometimes loses effectiveness, & can produce ______
Definition
dyskinesia
Term
The end-stage of Parkinson's patient progresses to total ______
Definition
akinesia
Term
The symptoms of Huntington's Disease are essentially opposite those of Parkinson's Disease, i.e. ______
Definition
hyperkinesia
Term
______ is the expression of dance-like movements that represent the intrusion of fragments of unwanted motor programs into the normal flow of motor acts
Definition
chorea
Term
Huntington's Disease is a rare _______ genetic disorder that affects 30,000 Americans
Definition
autosomal dominant
Term
The principle defect of Huntington's id a loss of ______ in the indirect pathway
Definition
striatal GABA neurons
Term
The Huntington's mutation is on the short arm of chromosome 4 & codes for the protein ______
Definition
huntingtin
Term
The Huntington's mutation consists of a series of CAG _____ repeats that gives the protein a polyglutamine tail
Definition
trinucleotide
Term
In ______, loss of striatal GABA neurons in the indirect pathway removes an important balance on the direct pathway, the overall effect of which is a more complete disinhibition of thalamocortical drive
Definition
Huntington's
Term
Huntington's removes the ability of the basal ganglia to suppress maladaptive motor programs, which then intrude into the patients normal voluntary movements, which probably explains the ______ symptoms
Definition
hyperkinetic
Term
In Huntington's, drugs that block ______ receptors partly ameliorate the symptoms
Definition
dopamine
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