Synaptophysin according to the Human Protein Atlas (a great resource) is involved in synaptic plasticity and possibly other functions.
I tested this antibody using Human and Mouse tissues and got great results. The procedure is relatively easy to do and staining on both species is strong.
Watch out though, the staining on human pancreas tissues produces background stain much faster than other tissues. Might want to cut the time down for pancreas tissues.
This antibody was tested in 2017 but used many times for several clients over the years. This is an easy protocol for automated machines.
As always, when testing this and all new protocols, be sure to use your controls first to view staining results. The protocol may need to be tweaked to your tissues.