17 Basal Ganglia Flashcards
Which are the more predominant neuron in the striatum: spiny or aspiny?
95% are spiny neurons. They are smaller than aspiny neurons.
What are the spines on spiny neurons for?
specialized for receiving terminals from other brain regions
Which type of neuron has long axon that leaves the striatum?
spiny neurons are projection neurons. Aspiny neurons have short axons that do not leave striatum.
What neurotransmitter do all spiny neurons use?
GABA (all), ENK (only those that project to GPe), subsance P (only those that project to GPi)
What region do SP neurons project to?
GPi, SNc, and SNr
What region to ENK neurons project to?
GPe (ENK for E)
Where are substance P terminals located in substantia nigra?
pars compacta (upper shelf) and in region of substantia nigra below dopaminergic receptors (pars reticulata)
Which dopamine receptor type is specific for ENK? Is it excitatory or inhibitory?
D2. Inhibitory
Which dopamine receptor type is specific for SP (and dynorphin)? Is it excitatory or inhibitory?
D1. Excitatory
What is the main function of straito-SNr neurons acting on D1 receptors via SP?
promote eye movement
What is the main function of straito-SNc neurons acting on D1 receptors via SP?
regulate dopaminergic neurons
What is the main function of striato-GPi neurons acting on D1 receptors via SP?
promote limb movement
Which striatum interneuon uses GABA?
all except cholinergic. (parvalbuminergic, somatostatinergic, calretinergic)
Which striatum interneuron is impervious to Huntingtons disease? What peptide do they make?
somatostatin internuerons.
They make neuropeptide Y (NPY)
(table later also says that calretinergic and cholinergic survive, but parvalbuminergic definitely eat shit and die)
What is the action of cholinergic interneurons?
oppose DA action
What is the action of parvalbuminergic interneurons?
inhibit PNs to sharpen activity
What is major neuron type in globus pallidus?
large aspiny neurons
Where does GPe project to?
subthalamic nucleus
Where does GPi project to?
motor thalamus (made of ventral anterior nucleus and ventral lateral nucleus)
Which brodman area does VA (ventral anterior nucleus) project to? VL?
area 6.
VL to area 4
What are the three major inputs to striatum?
cortex, thalamus, and substantia nigra
Where does almost all of the cerebral cortex project to?
striatum
What layer are the cortical neurons that project to the striatum in?
layer 5 (pyramidal neurons)
Which dopaminergic terminals are located in GPe? GPi?
None. Dopaminergic terminals are in caudate and putamen
Which part of globus pallidus is invovled in direct pathway?
GPi
Which part of globus pallidus is invovled in indirect pathway?
first GPe, which is inhibited to allow STN to promote GPi, which will then inhibit motor cortex
What is the primary transmitter of STN (subthalamic nucleus)? excitatory or inhibitory?
Glutamate, excites
What is the primary transmitter of motor thalamus ? excitatory or inhibitory?
glutamate, excites
What is the primary transmitter of SN pars reticulata? excitatory or inhibitory?
GABA, inhibits
What is the primary transmitter of striatum? excitatory or inhibitory?
GABA, inhibits
