Fig. 8

a Endocrine cells from the intestinal epithelium of an acanthocephalan infected specimen of Squalius cephalus that are immunofluororeactive to the serotonin antiserum (left image) and contain a met-enkephalin-like substance (middle image). Note the “reservoir-like” appearance of the met-enkephalin immunofluoropositive endocrine cell (middle and right images). b An open type endocrine cell that is immunofluororeactive to both the anti-met-enkephalin (left image) and to the anti-serotonin (middle image) anti-sera. The right image shows the co-localisation of the two neuromodulators within the same endocrine cell. Scale bars 20 μm