N-Acetyl-L-histidine monohydrate (NAH) also exhibits a strong phylogenetic component in that it is a major osmolyte in the brain and eye of teleost (bony) fish, amphibians and reptiles, but is present in much lower amounts in brain and other tissues of homeothermic (endothermic) vertebrates.

Bis(methylthio)-2-nitroethylene is an organic compound.

FM4-64 (SynaptoRedTM C2) is a styryl dye that stains stably but does not fluoresce in aqueous solution.FM4-64 does not passively diffuse into the plasma membrane bilayer and must be actively transported across the membrane.