2.29 Basal Ganglia Flashcards
Why are basal ganglia not actually ganglia?
- not in the CNS
- now called basal nuclei
What are basal ganglia overall?
functional loops that are connected with the pyramidal tracts (motor tracts)
What can damage to basal ganglia cause?
abnormal behavior and movement
basal ganglia affect this system
limbic (emotion, cognition)
damage to caudate
get problems with decision making
head of caudate
- helps take all sensory input in to make appropriate decisions
- integrates surroundings and inputs
premotor cortex (function)
- aka prefrontal cortex
- similar functions for motor planning to head of caudate
How do the head of caudate and premotor cortex work?
work together
reading social cues requires
combo of input from basal ganglia and amygdala
striatum
caudate + putamen
lentiform nucleus
putamen + globus pallidus
names of substantia nigra parts
2 separate structures
SNpc (pars compacta)
SNpr (pars reticularis)
Which part of the substantia nigra is pigmented?
SNpc
Where does pigment of substantia nigra come from?
pigment comes from neuromelanin
- expressed in dopaminergic (emotion/movement) and cholinergic (memory formation)cells in the brain
function of melanin/neuromelanin
neutralizes free radicals
When is neuromelanin expressed most?
- when you’re very young and very old
- provides protection for cells
function of SNpc
widespread modulation of BG and movement/emotion
SNpr
- major BG output nucleus
- functionally different from SNpc
- modulation
SN
substantia nigra
STN
subthalamic nucleus
blood supply to SN and STN
perforating branches of
- posterior cerebral
- posterior communicating
blood supply to striatum
- perforating branches of middle cerebral artery (MCA)
- aka lenticulostriate arteries
blood supply to globus pallidus
anterior choroidal artery (branches off of the carotid artery)
blood supply to caudate
branches of anterior cerebral (medial striate)
What type of movement do the basal ganglia influence?
influence voluntary movement
How do basal ganglia influence voluntary movement (overall)?
- senses are integrated
- prefrontal cortex and head of caudate make decisions on motor output given the circumstances
- integrate emotions, stress level, what’s going on around you, etc.
