Substantia nigra pars compacta SNpc

In normal state, L-DOPA is biosynthesized from L-tyrosine, then it is converted by the enzyme tyrosine hydroxylase (TH) to form dopamine in the dopaminergic neurons (Nakashima et al. 2011). When dopamine is released from substantia nigra pars compacta (SNpc), it binds to the D1 type receptor and D2 type receptor resulting in an increase or decrease of PKA. 

---