Figure 2.

A. Mitochondria (blue) are highly dynamic organelles localized throughout retinal ganglion cells axons shown in this live whole mount image of the optic nerve [166]. B. Growth cones (boxed regions) at the tips of growing axons and dendrites have a protrusive, actin-rich, peripheral domain (red) that pushes the growth cone's membrane peripherally. A transition zone separates the peripheral domain from the microtubule rich central domain (light green). Within the central domain, mitochondria (dark green) are highly dynamic, often undergoing fission and fusion events that constantly change the organization of the mitochondrial network in active growth cones. C. Mitochondrial fission and fusion events are regulated by distinct classes of proteins. Mfn1 & 2 and Oap1 regulate mitochondrial outer and inner membrane fusion respectively, whereas D. DRP-1 is a major factor in mediating mitochondrial fission. Additional proteins, like Miro and syntaphilin, among others, regulate mitochondrial transport and docking respectively.