The Basal Ganglia and Movement Disorders Flashcards
What are the structures of the basal ganglia?
Striatum, globus pallidus, substantia nigra, subthalamic nucleus
What are the primary division of the striatium?
Dorsal and Ventral
What are the divisions of the Dorsal striatum?
Caudate and putamen
What are the divisions of the ventral striatum?
Nucleus abducens, septum pallucidem and olfactory
What are teh primary divisions of the globus pallidus?
External and internal
What are the divisions of the internal globus pallidus?
Outer portion and inner portion
What are teh priary divisions of the substantia nigra?
Pars compacta and Pars reticulata
What is the secondary division of teh pars reticulata?
Parslateralis
What is the most common neuron in the basal ganglia?
Medium spiny neurons form most of the connections that exist in the basal ganglia
What is the function of the basal ganglia?
They are a set of input and output structures
Input= receive direct projections from the cerebral cortex
Output= project back to the cerebral cortex
What circuit does the basal ganglia participate in?
Cortico-basal-ganglia-thalamo-cortical circuit
What is the basic circuit of the Cortico-basal-ganglia-thalamo-cortical circuit?
Cortex —> input (striatum) —> output (pallidum) —-> thalamus —-> cortex
What are the 4 loops in the Cortico-basal-ganglia-thalamo-cortical circuit?
Motor, oculomotor, prefrontal and limbic
True/ False: The basal ganglia are involved in “habit learning”
True
What neurons in the basal ganglia are most involved in habit learning?
Tonically active neurons
What are tonically active neurons?
Giant cholinergic interneurons
What type of cells do tonically active neurons act on?
Mediam spinal neurons (and they help shape the activity of these neurons
How are Ach release and dopamine related?
Ach release helps stimulate dopamine release
Regarding the basal ganglia….which types of cells have Dopamine receptors?
medium spinal neurons
Regarding the basal ganglia, what cells release Ach?
Tonically active Neurons)
What are two forms of dyskinesia (general)
Hyperkenetic dyskinesia
Hypokinetic dyskinesia
What is Hyperkenetic dyskinesia?
an increase of movement due to low levels of BG output (too little break action)
What pathological condition is associated with Hyperkenetic dyskinesia?
Huntington’s Dosease, chorea and Sydenham’s Chorea
What is Hypokinetic dyskinesia?
a decrease of movement due to high levels of BG output (too much break action)
What pathological condition is associated with Hypokinetic dyskinesia?
Parkinson’s Disease
What is Sydenham’s Chorea?
An autoimmune reaction to childhood infection with Group A stretococcus infection
What part of the basal ganglia does Sydenham’s Chorea usually effect?
Striatum
What is huntington’s disease classified by?
Rare autosomal dominant disorder with progressive dementia and choriform movements
In huntington’s which basal ganglia pathway is knocked out? Direct? Indirect?
Indirect (so there basal ganglia has no break system)
What is characteristic of Parkinson’s disease?
Difficulty initiating movement, slowing and diminished ROM tremor at rest. slow, shuffling gait
What neurotransmitter is reduced in parkinson’s disease? And what is the result of this loss?
Dopamine (receptros lost too D1 and D2)
Leads to a hyperactive break
What pathway is knocked out in parkinson’s disease? Direct? Indirect?
Direct
How is huntington’s treated?
Block the direct pathway via antidopinergic and dopamine depleting grugs
What is a side effect of long term treatment for Huntington’s disease?
Tardive dyskinesia
How is parkinson’s treated?
L-DOPA (short term), Dopamimetics (longer acting), MAO-B/ COMT inhibitors, anti cholinergics
surgical treatment (to cut the break)
deep brain stimulation
stem cells(but can’t regulate dopamine well)
What is the side effects of L-DOPA?
Dyskinesia and hallucination
After a while, treatment for parkinson’s can mimic…
a Huntington’s patient
