A morphometric analysis of synaptic vesicle distributions.

Synaptic vesicle populations have been morphometrically analyzed for size and density. Populations composed of a single size class of vesicles are represented by normal (Gaussian) or positive (log-normal) skew histograms. Populations with multiple size classes generate negative (left) skew distributions. Fixatives containing aldehydes differentially affect these distribution patterns but vesicles are able to withstand tonic effects over a wide range. Reader bias' contribute the most error in the data-collecting process. But despite this, the sizing of vesicle populations can be accomplished with great accuracy. Vesicle density computations, on the other hand, vary over a wide range and are of less value for comparative purposes.