Basal ganglia Flashcards
basal ganglia influence movement by output from ___ to ___
SNr/GPi to brainstem and thalamus
Basal ganglia are mostly ___ ergic with the exception of __-
GABA, STN; cortex and thalamus are also glutaminergic
Structures of direct and indirect paths
Cortex/thalamus>striatum>SNr,GPi; striatum>GPe>STN>SNr/GPi
neurons projecting to the GPe express ___ receptors which make the neuron fire ___ frequently
D2; less
extrastriatal basal ganglia exhibit____ b/c the ouput is ___
autonomous activity; GABAergic
saccadic eye movement is the best example of ___ pathway
direct
SNc neurons in learning
always have tonic firing but you get a burst for unexpected rewards. Associative learning switches from reward to stimulus predictive of reward
Long term changes in corticostriatal synpases:
Long term potentiation drives behavior and requires D1 activation. Long term depression opposes behavior and requires D2
Cause of PD
degeneration of SN dopamine neurons
walk thru steps of indirect path in PD
increased striatal inhibition of GPe so decreased inhib of STN so increased stimulation of SNr/GPi so increased inhib of movement
genetics of huntingtons
completely penetrant, AD, expression related to the number of CAG repeats
symptoms and causes of huntingtons
Early: hyperkinesias (death of striato-GPe neurons). Late: akinesia and dementia (death of striato-GPi neurons and widespread degeneration)
how does deep brian stim work in PD
high frequency DBS disrupts synchronous Beta Band activity and makes it irregular and asynchronous
neurotransmitter changes in Huntingtons
decreased GABA and ACh, increased dopamine.
Huntington tx
tetrabenazine and reserpine (limits dopamine release by inhibiting VMAT). Haloperidol (dopamine receptor antagonist)
