Monoamine-containing subependymal cells of the lamprey: evidence from combined fluorescence histochemistry and electron microscopy.

Two types of monoamine-containing subependymal cells were studied microspectrofluorometric analyzes showed that yellow fluorescent cells contained 5HT and blue-green fluorescent cells dopamine (DA). These type types of fluorescent cells could be recognized also in a thin section (about 250 nm thick) mounted on a reference grid. Electron microscopy of the same section revealed that electron dense granules in the 5HT-containing cells are larger (80-140 nm) in size than those in the DA-containing cells (60-100 nm).