Basal ganglia Flashcards
Basal ganglia are important in
voluntary movements and making postural adjustments
Basal ganglia receives …. input
cortical
Basal ganglia output to cortex –> …
provides negative feedback to cortex to modulate movement
basal ganglia - structures
- striatum (ραβδωτό)
- Lentiform (φακοειδής)
- Substantia nigra
- subthalamic nucleus
basal ganglia - striatum =
putamen + caudate
basal ganglia - Lentiform =
putamen + globus pallidus
basal ganglia - putamen - responsible for
motion regulation
basal ganglia - caudate - responsible for
cognitive
globus pallidus is divided to
- Globus pallidus externus
2. Globus pallidus internus
basal ganglia - 2 main pathways
- excitatory pathway (direct)
2. inhibitory pathway (indirect)
basal ganglia - excitatory (direct) pathway –> (action)
increases motion
basal ganglia - inhibitory (indirect) pathway –> (action)
decreases motion
basal ganglia - excitatory (direct) pathway:
cortical inputs (glutamine) stimulate the striatum GABA neurons, which inhibits GABA neurons of Globus pallidus internus/substantia nigra pars reticulata --> disinhibition of the thalamus --> stimulate Motor cortex --> increases motion
basal ganglia - striatum to Globus pallidus internus/substantia nigra pars reticulata - neurotransmitters?
GABA
with Substance P (coneurotransmitter)
basal ganglia - inhibitory (indirect) pathway:
cortical inputs (glutamine) stimulate the striatum GABA neurons which inhibits GABA neurons of Globus pallidus externus --> disinhibition of STN --> STN stimulates GABA neurons of Globus pallidus internus/substantia nigra pars reticulata --> inhibition of thalamus --> decreases motion
basal ganglia - cortical to striatum - neurotransmitter
glutamate
striatum to Globus pallidus externus - neurotransmitter
GABA with Enkephalin (coneurotransmitter)
basal ganglia - dopamine pathway
Substantia nigra pars compacta –> dopamine –> (striatum) binds to D1 stimulating the excitatory (direct) pathway, and to D2, inhibiting the inhibitory (indirect) pathway –> INCREASED MOTION
basal ganglia - dopamine pathway - final result (explain)
INCREASED MOTION (D1 stimulates the direct, D2 inhibits the indirect)
basal ganglia - ach pathway defintion
ach neurons of striatum drives the indirect pathway –> decreasing cortical excitation
subthalamic nucleus to globus pallidus internus - neurotransmitter
glutamate
basal ganglia - dopamine pathway - dopamine is secreted by
Substantia nigra pars compacta
