Figure 1.

Schematic of endolysosomal trafficking and autophagy in neurons. Distinct endosomal subclasses are associated with particular sets of Rab GTPases. Early endosomes are Rab5-positive, late endosomes are Rab7-positive, and recycling endosomes are Rab11-positive. Endosomal trafficking is differentially regulated in dendrites versus axons of neurons. Mature lysosomes with high degradative capacity are located primarily in the soma or proximal neurites. Immature lysosome-like organelles are found in distal dendrites and axons. Axonal autophagosomes initiate largely in distal regions of the axon and gain retrograde motility through fusion with late endosomes to form amphisomes and coupling with dynein motors. In contrast, dendritic autophagosomes undergo bidirectional motility or oscillate within a confined region along the dendritic shaft.