Basal Ganglia Flashcards
Basal Ganglia- movement
Regulate intensity of slow or stereotypes movements
Inhibit antagonistic + unnecessary movements
Switch motor programmes (stop or start)
Neural structures in basal ganglia
Caudate nucleus
Putamen
Globus pallidus
Caudate nucleus
C shaped nuclei in frontal lobe
Head region curves + extends to form elongated body, tapering at tail and ending in temporal lobe
Putamen
Large, rounded nuclei located in forebrain
Connected to caudate nucleus at head region of caudate
Globus pallidus
Pale body Internal segment (GPi) --> output to thalamus External segment (GPe) --> relays info between other basal ganglia nuclei + internal globus pallidus
Internal capsule
White matter structure
Separates lentiform nucleus + caudate nucleus
Caudate nucleus blood supply
Middle cerebral artery (body)
Anterior cerebral artery (anterior)
Putamen blood supply
Middle cerebral artery
Anterior cerebral artery (anterior)
Globus pallidus
Middle cerebral artery
Anterior choroidal
Internal capsule
MCA (middle)
ACA (anterior limb)
Anterior choroidal (posterior limb)
Neuronal projections into basal ganglia are from
Cerebral cortex
Substantia nigra pars compacta
Cerebral cortex projections
Almost all project directly to caudate + putamen
Majority from frontal + parietal
–> projections referred to as corticostriatal pathway
Substantia nigra pars compacta projections
Located in midbrain
Dopaminergic input to caudate nucleus + putamen
–> progressions referred to as nigrostriatal pathway
Input zone of basal ganglia
Corpus striatum- caudate nucleus + putamen
Corpus striatum neurones
75% medium spiny neurones
Inputs to medium spiny neurones
Cortical neurones (glutamatergic) Substantia nigra pars compacta neurones (dopaminergic) Local circuit neurones within corpus striatum (GABAergic)