Caudate nucleus + putamen
Striatum (striped appearance)
Nucleus accumbens alternate name
Putamen + globus pallidus
What is the ansa lenticularis
Outflow from globus pallidus; GABA-ergic projection to thalamus
What type of project (ex/in) is the Striatum to the GPi?
What receptors on the Striatum do SN DA bind in the direct pathway?
What is the role of the STN in the indirect pathway
Excites the inhibitory neuron from the GPi to the thalamus, resulting in more inhibition
- STN to GPi = subthalmic fasciculus
-GPi to thalamus = ansa lenticularis
Which DA receptors do SN DA bind in the indirect pathway
D2; inhibits excitatory interneuron; reduces the activity of the STN (cortical input increases excitatory interneuron simultaneously, increasing STN activity)
Goal of indirect pathway
Inhibit competing movements
Goal of direct pathway
Facilitate target-oriented movements
Describe blood supply to basal ganglia
Nucleus accumbens is the fusion of ___
Head of caudate and putamen
Where is the Substantia nigra located
Rostral midbrain -- dark appearance
Which 2 fibre tracts form the thalamic fasciculus?
1) lenticular fasciculus and ansa lenticularis (GPi)
Which fibres travel in the subthalamic fasciculus
1) inhibitory projections from GPe to STN; excitatory projections from STN to GPi
The anterior choroidal arteries branch off of which main artery?
Internal carotid (along with MCA)
Which BG structures are supplied by anterior choroidal artery?
1) Tail of caudate; 2) Posterior portions of GP and Putamen
Which BG structures are supplied by the ACA
Branches penetrate to head of the caudate and anterior part of Putamen and GP (opposite of anterior choroidal arteries)
Which BG structures are supplied by the MCA?
Branches supply putamen and globus pallidus (middle portions) and the BODY of the caudate nucleus
Which BG structures are supplied by the PCA and posterior communicating artery?
Entire thalamus (deep branches); SN, STN, posterior caudate