Enlargement of synaptic vesicles in degenerating nerve endings: a comparison between cat and monkey.

The synaptic vesicles of optic nerve endings in the lateral geniculate nucleus of cats and monkeys were measured following eye enucleation. A notable increase in the mean vesicle volume was found in both species. Increments in the values of standard deviation were also noted. Comparison of the results obtained indicate that changes are faster in cats than in monkeys. An explanation for difference is proposed.