How much glutamate does one synaptic vesicle hold? · Grey Matter

Thousands of molecules, with estimates that depend on the method.

How much glutamate does one synaptic vesicle hold?

Thousands of molecules, with estimates that depend on the method. Biochemical analyses of isolated vesicles gave about 2,000 to 4,000, models fitted to the response of postsynaptic receptors gave about 5,000 to 9,000, and a direct electrochemical count in single vesicles found about 8,000. Release happens in these packets (quanta), so the smallest signal a synapse can send is one vesicle's worth.