Basal ganglia Flashcards
function of basal ganglia
involved in all aspects of motor control and movement, also in cognition, emotion and motivation
striatum contains
nucleus accumbens
caudate
putamen
4 parts of basal ganglia
striatum
globus pallidus
sub thalamic nuclei
substantia nigra
extrapyramidal motor system issues
not corticospinal
BG and cerebellum issues
caudate shape and location
c-shaped and lateral to lateral ventricle
input to basal ganglia
usually from cortex and usually to striatum
outputs of basal ganglia
globus pallidus internal
substantia nigra pars reticulata
how is the basal ganglia outputs managed
a balance of inhibitory and excitatory to allow for normal movement and suppress unwanted movements
how does the basal ganglia influence movement
by influencing output of the corticospinal tract (not extrapyramidal)
pathway through the basal ganglia
cortical input
BG input nuclei
BG output nuclei
thalamic relay nuclei
cortical targets
pigmented neurons in the substantial nigra release what
dopamine
direct pathway issue to affect movement
direct pathway is normally excitatory via disinhibition
indirect pathway issue to affect movement
indirect pathway is normally inhibitory through disinhibition of an inhibitory pathway
Pathology of Parkinson’s on the pathway-indirect pathway
Under inhibition of STN to over excite MGP and over inhibit thalamus and under excite cortex
Pathology of Parkinson’s on the pathway- direct pathway
loss of inhibition on the MGP to over inhibit thalamus and under excite cortex
