Question

Which of the following is true of Parkinson’s disease? Question options:

A) Loss of dopamine neurons that project to the caudate/putamen leads to a hypokinetic disorder

B) Loss of glutamatergic neurons in the thalamus that project to the motor cortex leads to a hypokinetic disorder

C) Loss of input from the cerebral cortex to the caudate/putamen leads to a hyperkinetic disorder

D) Loss of dopamine neurons in the subthalamic nuclei leads to a hyperkinetic disorder

An explanation would be helpful to, thank you!

Answer 1

A. Loss of dopamine neuron that project to caudate/putamen leads to hypokinetic disorder

• Parkinson's disease is dueto depletion of dopaminergic neuron in basal ganglia (substantia nigra)
• Dopamine acts as inhibitory signal for GABAergic neuron.
• GABA acts as inhibitor neurotransmitter and thus decrease decrease excitatory input to motor cortex
• When Dopamine level decreases in Parkinson's then inhibition on GABAergic neuron is decreased thus they becomes mor active
• This leads to more inhibition of motor impulse that lead to hypokinesia