The nervous system of Amphilina foliacea (Platyhelminthes, Amphilinidea). An immunocytochemical, ultrastructural and spectrofluorometrical study

The nervous system of young and adult Amphilina foliacea was studied with i mmunocytochemical, electron microscopical and spectrofluorometrical methods . The general neuroanatomy is described in detail. New data on the structur e and development of the brain were obtained. The 5-HT and GYIRFamide-immun oreactivities occur in separate sets of neurones. The innervation of the re productive organs is described. The fine structure of 2 types of neurones i n the CNS, a sensory neurone, a 'glial' cell type, the neuropile and the sy napses are described. The level of 5-HT varies between 0.074 and 0.461 mug/ g wet weight. This is the first detailed study of the nervous system of A. foliacea. Earlier data on the structure of the nervous system in A. foliace a published in Russian are introduced into the discussion. The study provid es data that can be used when considering the phylogenetic position of Amph ilinidea.