Question

Explain the relationship between DA activity and dopaminergic neuronal innervations in a normal (i.e., 100% intact motor system) and explain what happens to this relationship in a Parkinson’s condition where motor neuron degeneration is progressive (i.e., reducing the efficiency of the intact system by 50%, 20%, and 10%). Review the passive stabilization program to gain a better understanding of this question.

Answer 1

Dopamine is a neurotransmitter and binds to many receptors in brain and cause their activation. Dopamine regulates various dopaminergic pathway that helps in motor control, reward behaviour and hormone release control.

Dopamine exerts its effect by binding to and activating dopaminergic receptors. Activation of these receptors either cause excitation or inhibition.

The nigrostriatal pathway is a dopaminergic pathway connecting the substantia nigra pars compacta(SNc) with the dorsal striatum. It is involved in the production of movement.

Loss of dopamine neurons in the SNc in Parkinson's disease cause marked reduction in dopamine function in this pathway. Parkinson’s characterised by cell death in basal ganglia affecting the dopamine producing neurons in the substantia nigra pars compacta. This results in low level of dopamine causing higher demand of effor for any movement.