Table 1.

Target dopaminergic neuron densities and dopamine production.

	Rat	Human
No. of dopaminergic neurons required:
Dopamine cell therapeutic threshold	≥1200–2400a	≥40,000–80,000b
Therapeutic dopamine production	50–100 nmc	7 ng/mg of tissued

^aData from Isacson, Bjorklund⁶³

^bData from Bjorklund and Lindvall⁵³

^cData from Robinson, Venton et al.⁶²

^dData from Kish, Kalasinsky et al.⁶⁴