Optimizing mitochondrial maintenance in extended neuronal projections
Fig 1
Schematic of quantitative models for mitochondrial maintenance in long neuronal projections.
(a) Mitochondria are produced at the soma at rate kp, move processively with velocity v, and can stop at one of n discrete sites with high metabolic demand. Mitochondrial health degrades continuously with rate kd. Gray box represents the modeled linear domain of length L. (b) Two models for mitochondrial exchange at demand sites. In the CoG model, stationary mitochondria re-enter the motile population with rate kw while passing motile mitochondria stop with probability ps. Stopping and restarting rates are independent of mitochondrial health; on average, however, restarting mitochondria will be less healthy than when they first stopped at the site, due to degradation in the stationary state. In the SS model, transient fusion events occur with probability pf each time a motile mitochondrion passes a permanently stationary one [53].