Quantum size distribution of the DAergic and GABAergic events. The distribution of the DA quanta (A) ranged from ∼103 to 105 molecules, and the mean size of the coincident events was not significantly different from that of the single events. Conversely, the distribution of the quanta of GABA molecules (B) exhibited a broader spectrum of sizes because it varied from 103 to 106 molecules. The DA quanta associated with the largest GABA quanta were one order of magnitude smaller than the accompanying packet of GABA. Comparison of the distributions of the quantal sizes of DA and GABA shows that both populations, but especially that of the GABAergic events, were skewed toward smaller sizes.
