This animation depicts three membrane trafficking routes in a mammalian neurosecretory cell, highlighting the changing Cl- concentrations and pH values of the various endosomal subcompartments. The focus is on the endocytotic pathway and the different paths taken by clathrin-coated vesicles: the pathway for receptor recycling to the plasma membrane, the lysosomal pathway, or the pathway for synaptic vesicle recycling (in neurons). Each compartment shown has a distinctive pH and [Cl-], with values for pH indicated in blue and values for Cl- indicated in orange. This animation will be useful for teaching cell biology and highlighting both the dynamic nature of vesicular traffic and the changes in ionic balance associated with different cellular compartments.