Originally Posted by pdinfo

As I understand it, the phenomenon of biochemical "feedback inhibition", as in Levodopa being the most inhibtor of its own natural biosynthesis (a subject covered elsewhere at lenght), when supplied from outside, as in PD, is a particular case of the general chemical principle of "LeRichelieau". Is this correct? Resident biochems called to duty on this one).

Or put in very non-technical terms, one could say that "feedback inhibition" is the same as the "use it or loose it" common sense principle, according to which, for example in the case of a muscle or muscles which are seldom used or exercised, they would tend to shrivel up.
In PD, where the natural biosynthesis of Levodopa (and therefore Dopamine) is impaired, taking exogenous Levodopa, while dramatically effective on an immediate basis, in the long run it is diabolically inhibiting of the already compromised natural biosynthesis of itself, as if the body was "saying": "well, if I am getting ready made Levodopa, why bother to make my own, more so when I am already having a hard time making the stuff to begin with", thus closing the viscious circle of a lifetime dependency on externally supplied Levodopa.

1. Is all of the above correct, or mere rationalization.?