Basal ganglia

Question 1

Inhibitory characteristic

Answer 1

People prepare all actions but BG inhibits until action is selected, then also gates that action (starts and stops)

Question 2

Three nuclei

Answer 2

Cuadate and putamen form the striatum. Activation inhibits the globus via direct path

globus pallidus; output nucleus , regulates activity by relaying through the thalamus. Activation inhibited by striatum

Question 3

Eye movement initiation

Answer 3

Neurons in caudate nuclei fire just before eye movement initiation. Neurons in substantia nigra pars reticula cease firing. Burst of action potentials at the superior colliculi (horizontal eye movement)

Question 4

Direct pathway

Answer 4

Activation/gating motor responses. Initiate movements. If damaged: Parkinson

Question 5

Indirect pathway

Answer 5

External globus and subthalamic neucleus/cuadate. Inhibit motor response. When damaged: Huntington