4.2. Unresolved Mechanisms in These Findings
As noted earlier, in NHP models [The compound we used, PF-2562, is one of a series of non-catechol DIntriguingly, dihydrexidine, like its 2-methyl analog [The two most obvious are what are the optimal ligand properties in terms of intrinsic activity at canonical and non-canonical pathways to provide the highest therapeutic index. For example, it has been argued that the lack of β-arrestin activity will decrease desensitization due to chronic administration, yet it is also possible the receptor occupation needed to obtain antiparkinson effects will be too low in vivo to trigger these mechanisms. In that case, the non-canonical signaling of β-arrestin (or other unstudied pathways) may be very important.The availability of newer generation D