Term
| what are the 5 major components of the basal ganglia? |
|
Definition
| caudate, putamen, globus pallidus, substantia nigra, subthalamic nuclei |
|
|
Term
| what is the outermost portion of the basal ganglia? |
|
Definition
|
|
Term
| what part of the basal ganglia lies just interior to the caudate? |
|
Definition
|
|
Term
| what is the most inferior part of the basal ganglia |
|
Definition
|
|
Term
| what are the 2 parts of the striatum |
|
Definition
|
|
Term
| what are the 2 parts of the globus pallidus |
|
Definition
|
|
Term
| what are the two parts of the substantia nigra? |
|
Definition
|
|
Term
| what divides the caudate from the putamen? |
|
Definition
|
|
Term
| what divides the globus pallidus internal segment from the subthalamic nucleus and substantia nigra? |
|
Definition
|
|
Term
| what happens in the internal capsule? |
|
Definition
| all the motor fibers go to/from spinal cord and cortex |
|
|
Term
| to what other structures are the subthalamic nuclei functionally (not physically) connected with? |
|
Definition
| globus pallidus internal and external, substantia nigra |
|
|
Term
| where is the subthalamc nucleus in relation to the substantia nigra? |
|
Definition
| subthalamic nucleus is superior to the substantia nigra and inferior to the thalamus |
|
|
Term
| what neurotransmitter is used by the subthalamic nuclei cells? |
|
Definition
|
|
Term
| what is the only excitatory neurotransmitter in the basal ganglia? |
|
Definition
|
|
Term
| why is the shape of the caudate helpful? |
|
Definition
| the c shape of the caudate allows for lots of area for input from the cortex |
|
|
Term
| do the caudate and putamen have a homunculus? |
|
Definition
|
|
Term
| does the BG project contralaterally or ipsilaterally? |
|
Definition
|
|
Term
| does the cerebellum project contralaterally or ipsilaterally |
|
Definition
|
|
Term
| to what structure does most of the BG output go? |
|
Definition
|
|
Term
| how are the BG and cerebellum similar? |
|
Definition
| they are both large connections of nuclei that modify movement |
|
|
Term
| is the output of the cerebellum excitatory or inhibitory? |
|
Definition
|
|
Term
| is the output of the BG excitatory or inhibitory/ |
|
Definition
|
|
Term
| which is involved more on complex movements: BG or cerebellum? |
|
Definition
|
|
Term
| does the BG have direct input/output with spinal cord? |
|
Definition
|
|
Term
| does the cerebellum have direct input or output with spinal cord? |
|
Definition
|
|
Term
| what structures input to the basal ganglia? |
|
Definition
| cortex, midbrain, thalamus, limbic system, raphe nuclei |
|
|
Term
| to where does information go after BG and after thalamus? |
|
Definition
| motor cortex, then to other centers/nuclei and to spinal cord to modify movement |
|
|
Term
| what is the input zone within the basal ganglia? |
|
Definition
|
|
Term
| what neurotransmitter goes to the striatum from its input areas? |
|
Definition
|
|
Term
| what neurotransmitter is output by the striatum |
|
Definition
|
|
Term
| are the raphe nuclei big, medium, small? |
|
Definition
|
|
Term
| where are the raphe nuclei located? |
|
Definition
|
|
Term
| what is the main function of the raphe nuclei |
|
Definition
| release serotonin to the rest of the brain |
|
|
Term
| in what lobe is auditory information processed? |
|
Definition
|
|
Term
| in what lobe is physical sensation processed? |
|
Definition
|
|
Term
| in what lobe is movement directed |
|
Definition
|
|
Term
| is serotonin an excitatory or inhibitory neurotransmitter |
|
Definition
|
|
Term
| what happens if you have decreased serotonin |
|
Definition
| disorganized thinking, depression |
|
|
Term
| to where does the substantia nigra pars reticulata project and why? |
|
Definition
| to superior colliculus for head/eye movement |
|
|
Term
| to where does the GPI and subthalamic nucleus project |
|
Definition
|
|
Term
| are the globus pallidus internal and substantia nigra inhibitory or excitatory? |
|
Definition
|
|
Term
| does the BG store motor commands? |
|
Definition
|
|
Term
| what is the role of the basal ganglia in motor control? |
|
Definition
| Refine motor commands; Scale motor output; Integrate limbic input; Prepare muscle tone: Set posture; Integrate input from other areas of the brain |
|
|
Term
| what does the BG do to motor commands? |
|
Definition
| refine them and scale them |
|
|
Term
| what does the BG do with limbic input? |
|
Definition
| integrate it with motor information |
|
|
Term
| what are the 2 major pathways of the basal ganglia |
|
Definition
|
|
Term
| how does emotion manifest itself in motor commands? |
|
Definition
| we use movement to convey emotions |
|
|
Term
| what is the preparatory muscle tone? |
|
Definition
|
|
Term
| can the BG influence resting muscle tone? |
|
Definition
|
|
Term
|
Definition
| having postural muscles turned on so they can support other movement |
|
|
Term
| can the BG influence postural set? |
|
Definition
|
|
Term
| at what point during movement does the BG become activated? |
|
Definition
| after the muscle is prepared to move and before it actually moves: The plan for movement was executed and the muscles are prepared to respond. |
|
|
Term
| in what order do we get activation of globus pallidus internus, movement, muscle activation, putamen, and subthalamic nuclei? |
|
Definition
| in this order: muscle activation, subthalamic nucleus, globus pallidus internus, putamen, movement |
|
|
Term
| what parts of the cortex project to the caudate? |
|
Definition
| premotor, motor, supplementary motor |
|
|
Term
| besides the motor cortex, what else projects to the striatum? |
|
Definition
|
|
Term
| to what does the striatum project? |
|
Definition
|
|
Term
| besides the putamen, what else projects to the globus pallidus? |
|
Definition
| substantia nigra, subthalamic nucleus |
|
|
Term
| to what does the globus pallidus project? |
|
Definition
| substantia nigra, subthalamic nucleus, thalamus |
|
|
Term
| what happens to the information sent to the thalamus from the globus pallidus? |
|
Definition
| goes to motor cortex and/or spinal cord |
|
|
Term
| how does a disinhibitory circuit work? |
|
Definition
| an inhibitory cell inhibits another inhibitory cell so that the target cell receives less inhibition. |
|
|
Term
| how is the direct pathway an inhibitory circuit? |
|
Definition
| the caudate and putamen disinhibit the thalamus by inhibiting the inhibitory GP |
|
|
Term
| what is the effect of the direct pathway on the thalamus and cortex: excitation or inhibition? |
|
Definition
|
|
Term
| what is the effect of the indirect pathway on the thalamus and cortex? |
|
Definition
|
|
Term
| how is the indirect pathway an example of a disfacilitation circuit? |
|
Definition
| the inhibitory GP inhibits the thalamus from exciting the cortex |
|
|
Term
| do both parts of the BP communicate with the subthalamic nuclei? |
|
Definition
|
|
Term
| why does the GPI have projections to the reticular formation? |
|
Definition
| to assist in postural control |
|
|
Term
| what does the substantia nigra pars reticulata give to the striatum in the direct pathway? |
|
Definition
|
|
Term
| what does the substantia nigra pars reticulata give to the striatum in the indirect pathway? |
|
Definition
|
|
Term
| what does the GPE do to the subthalamic nuclei in the indirect pathway? |
|
Definition
| the GPE disinhibits the subthalamic nucleus |
|
|
Term
| what are the major output zones of the BG? |
|
Definition
| GP, substantia nigra pars reticulata |
|
|
Term
| describe the direct pathway |
|
Definition
| 1. cortex and substantia nigra pars compacta provide excitatory input to striatum. 2. striatum responds with inhibition to GPI. 3. GPI is disinhibited so it doesn't inhibit the thalamus. 4. the thalamus is able to excite the cortex |
|
|
Term
| describe the path of the indirect pathway |
|
Definition
| 1. substantia nigra pars compacta provides inhibitory input to striatum via D2 dopamine. 2. striatum responds with decreased inhibitory input to GPI. A subpopulation of neurons from the striatum additionally provide inhibitory input to the GPE. 3. this disinhibits the GPE from inhibiting both the GPI and the subthalamic nucleus. 4. The subthalamic nucleus excites the GPI plus the GPE is not inhibiting the GPI as much. 5. The GPI is now better able to do its inhibition and disfacilitation of the thalamus to reduce excitatory flow to the cortex |
|
|
Term
| in the indirect pathway, what is the effect of disinhibition to the subthalamic nuclei? |
|
Definition
| the subthalamic nuclei is no longer inhibited by the GPE, so it can have more excitation output to the GPI |
|
|
Term
| in the indirect pathway, what is the effect of the STN's excitation to the GPI? |
|
Definition
| the GPI is excited to decrease activation of the thalamus |
|
|
Term
| what part of the BG provides the major inhibitory output from the BG to the thalamus? |
|
Definition
|
|
Term
| what part of the caudate receives input from frontal cortex and limbic areas? |
|
Definition
|
|
Term
| what happens when you have problems with the medial caudate |
|
Definition
| disorganized thinking, schizophrenia |
|
|
Term
| what is the function of the substantia nigra pars reticulata? |
|
Definition
| receives input from the caudate and putamen and sends it outside of the basal ganglia to control head and eye movements |
|
|
Term
| what is the function of the substantia nigra pars compact? |
|
Definition
|
|
Term
| what part of the BG is associated with Parkinson's? |
|
Definition
| substantia nigra pars compacta |
|
|
Term
| why does the substantia nigra look dark? |
|
Definition
|
|
Term
| what is the effect of the direct pathway on the motor cortex? |
|
Definition
|
|
Term
| what is the effect of the indirect pathway on the motor cortex? |
|
Definition
|
|
Term
| what happens when you lose the nigrostriatal dopaminergic pathway |
|
Definition
| Parkinson's disease: upsets the balance of excitation and inhibition in the BG, reduces excitation of motor cortex |
|
|
Term
| what are the 2 categories of deficits of the BG? |
|
Definition
| hypokinetic disorders and hyperkinetic disorders |
|
|
Term
| what is the main symptom of hypokinetic disorders? |
|
Definition
| difficulty initiating movement |
|
|
Term
| what are the abnormalities of the BG pathways with hypokinetic disorders? |
|
Definition
| insufficient direct pathway output and excessive indirect pathway output |
|
|
Term
| what are the 2 types of hypokinetic disorders of the BG? |
|
Definition
| Parkinson's disease, Parkinsonism |
|
|
Term
| what are the pathway abnormalities associated with hyperkinetic disorders |
|
Definition
| excessive direct pathway output, insufficient indirect pathway output |
|
|
Term
| what are the 3 hyperkinetic disorders of the BG? |
|
Definition
| Huntington's Chorea, Hemiballism, Athetosis |
|
|
Term
| what are the symptoms of PD? |
|
Definition
| difficulty initiating movement; bradykinesia; flat affect; fatigue; difficulty interpreting sensory cues; poor balance responses; dementia; slowed central processing = loss of balance responses; reduced executive function; attentional deficits; difficulty with initiation or switching responses; learning and memory impairments |
|
|
Term
| how is movement initiation changed with PD |
|
Definition
|
|
Term
| how is speed of movement changed with PD |
|
Definition
|
|
Term
| how does facial expression change with PD |
|
Definition
| becomes more flat, inexpressive |
|
|
Term
| how do energy levels change with PD |
|
Definition
|
|
Term
| how does interpretation of sensation change with PD? |
|
Definition
|
|
Term
| how do balance responses change with PD? |
|
Definition
|
|
Term
| how does memory change with PD? |
|
Definition
|
|
Term
| how does attention change with PD? |
|
Definition
|
|
Term
| how does executive function change with PD? |
|
Definition
|
|
Term
| how does learning change with PD? |
|
Definition
|
|
Term
| what is the pathophysiology of PD? |
|
Definition
| deterioration of neurons in the substantia nigra pars compacta |
|
|
Term
| what is the result on the striatum of deterioration of neurons in the substantia nigra pars compact? |
|
Definition
| decreased dopa to striatum |
|
|
Term
| what is the result of decreased dopa to striatum on globus pallidus |
|
Definition
| decreased inhibition from striatum to globus pallidus (disinhibition of globus pallidus) |
|
|
Term
| what is the result on the thalamus of disinhibition of the globus pallidus? |
|
Definition
| increased inhibition from the globus pallidus of the thalamus |
|
|
Term
| what is the result on the cortex of increased inhibition of the thalamus? |
|
Definition
| decreased output of thalamus to cortex |
|
|
Term
| what is the result of decreased output of the thalamus to the cortex? |
|
Definition
| decreased supplementary m motor area activity and decreased movement related potentials |
|
|
Term
| In PD, how much dopamine has to be lost before symptoms are evident? |
|
Definition
|
|
Term
| what neurotransmitter initially compensates for the loss of dopamine in PD? |
|
Definition
|
|
Term
| what is associated with serotonin in deficiency in advanced Parkinson's? |
|
Definition
| walking and balance problems, depression, sleep disturbances, cognitive impairments |
|
|
Term
| which cognitive impairments are associated with serotonin deficiency in advanced PD? |
|
Definition
| insight, empathy, judgment |
|
|
Term
| what can improve pulmonary function and exercise tolerance in people with PD? |
|
Definition
| strengthening and exercise training |
|
|
Term
| what can improve movement in people with PD? |
|
Definition
| external cues and attentional strategies |
|
|
Term
| what is the reason for fatigue in people with PD? |
|
Definition
|
|
Term
| what are treatments for PD? |
|
Definition
| medication, surgery, deep brain stimulation, fetal implants of GP tissue, exercise |
|
|
Term
| what medications are used to treat PD |
|
Definition
| Leva Dopa or other dopa agonists |
|
|
Term
| what surgeries are used to treat PD? |
|
Definition
| lesion of the GP or thalamus so that the inhibition can't be passed along |
|
|
Term
| what types of exercise help maintain mobility and function in people with PD? |
|
Definition
| high intensity exercise, music and dance |
|
|
Term
| does dopamine cross the blood-brain barrier? |
|
Definition
|
|
Term
| does Levodopa cross the blood-brain barrier? |
|
Definition
|
|
Term
| what does Levodopa turn into? |
|
Definition
|
|
Term
| what does levodopa improve in a person with PT? |
|
Definition
| bradykinesia, reduces mortality rate |
|
|
Term
| does L-dopa improve tremor and dementia in people with PD? |
|
Definition
|
|
Term
| how long can you take L-dopa? |
|
Definition
|
|
Term
| what happens after 2-5 years of taking L-dopa? |
|
Definition
| there are too few functional neurons to process the L-dopa and compensate for decreased endogenous dopamine levels |
|
|
Term
| what are the side effects of L-dopa? |
|
Definition
| dyskinesias, behavioral effects |
|
|
Term
| describe the dyskinesias of L-dopa |
|
Definition
| repetitive involuntary slow writhing jerky |
|
|
Term
| how to relieve dyskinesia from L-dopa? |
|
Definition
|
|
Term
| what are the behavioral effects of L-dopa? |
|
Definition
| anxiety, insomnia, psychoses, nightmares, hallucinations |
|
|
Term
|
Definition
| a surgical lesion to a region of the thalamus |
|
|
Term
| how is a thalamotomy done? |
|
Definition
| a microscopic electrode tip is inserted into the area of the thalamus. The patient is alert the whole time. |
|
|
Term
| what are the effects of a thalamotomy |
|
Definition
| reduces tremor but does not prevent progression or improve akinesia or bradykinesia |
|
|
Term
|
Definition
| a surgical lesion to an overactive globus pallidus internus |
|
|
Term
| when might a pallidotomy be performed? |
|
Definition
| when a patient is no longer responding to L-dopa or has a complicated course of PD |
|
|
Term
| what are the effects of a pallidotomy |
|
Definition
| can improve gait freezing, tremor, rigidity, and some postural instability |
|
|
Term
| describe the procedure of implanting a deep brain stimulator |
|
Definition
| an electrode is surgically placed in the ventral thalamus, internal globus pallidus, or subthalamic nucleus |
|
|
Term
| does the patient have some control over the stimulation of deep brain simulation? |
|
Definition
|
|
Term
| what is the purpose of fetal transplants in PD |
|
Definition
| attempts to replace dopamine producing cells |
|
|
Term
| what does hemiballism look like |
|
Definition
| flailing movements of one arm and leg |
|
|
Term
|
Definition
| stroke or other damage to subthalamic nucleus |
|
|
Term
| is the effect of hemiballism contralateral or ipsilateral |
|
Definition
|
|
Term
| what is inhibited/excited inappropriately in hemiballism |
|
Definition
| decreased inhibition of thalamus and increased excitation of cortex |
|
|
Term
| how does someone get Huntington's chorea |
|
Definition
|
|
Term
| what is the pathophysiology of Huntington's |
|
Definition
| degeneration of the spiny cells in the caudate and putamen that produce acetylcholine |
|
|
Term
| what does Huntington's chorea look like |
|
Definition
| continuous movements of the face and limbs |
|
|
Term
| what happens to the caudate size with Huntington's chorea |
|
Definition
|
|
Term
| what happens to the size of the lateral ventricles with Huntington's chorea |
|
Definition
|
|
Term
| what is the overall role of the BG in movement? |
|
Definition
| generation of goal-directed voluntary movement |
|
|
Term
| In what parts of motor learning does the BG play a role? |
|
Definition
| initiating movement, selecting a motor pattern, sequencing movement, switching tasks |
|
|
Term
| is BG involved with implicit or explicit learning? |
|
Definition
| both, but our understanding of BG and implicit learning is better known |
|
|
Term
| what determines how big a role the BG plays in motor learning |
|
Definition
| the cortical area that is stimulating the BG |
|
|
Term
| describe some different corticostriatal loops that have different functions in learning |
|
Definition
| the affective loop involves learning about rewards; the visual loop involves learning about visual categories |
|
|
Term
| during what type of learning conditions is caudate activation greatest? |
|
Definition
| during dual task learning conditions |
|
|
Term
| why is the caudate activation greatest during dual task learning conditions? |
|
Definition
| because the caudate is associated with executive functions that involve coordinating 2 tasks at once |
|
|
Term
| how does BG disease impact categorical learning? |
|
Definition
| BG disease can impair categorical learning |
|
|
Term
| how can people with BG disease compensate for impaired categorical learning |
|
Definition
| can learn to categorize based on explicit memorization |
|
|
Term
| in PD, is dopa depletion equally severe in all portions of the striatum? |
|
Definition
|
|
Term
| if there is an area of decreased dopamine in the striatum and dopa is given, how is learning changed for that area? |
|
Definition
|
|
Term
| if there is an area of normal dopamine and dopa is given, how is learning changed? |
|
Definition
| too much dopa can reduce learning |
|
|
Term
| what does the BG do to motor commands? |
|
Definition
|
|
Term
| what does the BG do to input from other areas of the brain? |
|
Definition
| integrates it for movement |
|
|
Term
| is the BG involved in procedural learning |
|
Definition
|
|
