Basal Ganglia

Question 0

Striatum

Answer 0

Caudate and pudamen…separated by the internal capsule
Receives most of afferents output
-receives excitatory input from the cerebral cortex and thalamus
-Substantia nigra-excitatory and inhibitory

Question 1

Sub compartments

Answer 1

Striatum-caudate & pudamen
Globus pallidus: external and internal pallidus
Subthalmic nucleus
Substantia nigra

Question 2

Internal connection

Answer 2

• direct, indirect and nigostriatal pathways
• important to coordinate agonist and antagonist muscles
• both direct and indirect pathways begin in the striatum -caudate & pudamen

Question 3

Direct & indirect pathway

Answer 3

Direct:2 synapses -double inhibitory 
Overall excitatory 
Excites the M1...facilitates movement
Indirect:3 synapses triple inhibitory 
Overall -inhibitory...inhibits the M1 (inhibits movement)

Question 4

Nigrostriatal pathway

Answer 4

-modulates the direct and indirect pathway
-dopaminergic:projects from the Substantia nigra (pars compacta) releases dopamine to the striatum
Direct pathways has D1 dopamine receptors (depolarize)
Indirect pathways-has D2 dopamine receptors (hyperpolarize)
*has dual affect of exciting the direct and inhibiting the indirect ultimately exciting the system

Question 5

Parkinson’s disease

Answer 5

• Neurogenerative disease
• dopaminergic neurons in the substantia nigra …therefore don’t have the direct pathway as often
• symptoms-poor movement initiation, stoop, rigidity

Question 6

Treatment for PD

Answer 6

L-DOPA: a dopamine agonist-gets converted to dopamine, helps restore dopamine levels in the brain
Pallidotomy: neurological procedure in which the Globus pallidus is destroyed
Deep brain stimulation :a pacemaker is implanted in the brain and electrical signals are sent through wires to the brain

Question 7

Huntingtons disease

Answer 7

• progressive brain disorder caused by a defective gene
• due to selective loss of neurons in the indirect pathway, leading to too much excitation
• no cure