Localization of thiamine pyrophosphatase in synaptic vesicles

In the perikarya of pontine reticular formation neurons thiamine pyrophosphatase activity was localized within the innermost lamellae of the Golgi complex and, to a lesser extent, within cisternae of the rough endoplasmic reticulum. In axons, thiamine pyrophosphatase activity was localized within tubular profiles, presumed to be endoplasmic reticulum, and in axonal terminals it was found within presynaptic vesicles. This selective localization of pyrophosphatase activity suggests the derivation of synaptic vesicles from membranes of the Golgi complex.