fmrfamide and Fish-Diseases

Trematoda Opisthorchis felineus Rivolta, 1884 is the causative agent of dangerous parasite disease-opisthorchiasis, widespread in the Russian Federation. The details of the neuroanatomical localization of the serotoninergic and FMRFamidergic neurotransmitter elements as well as their functional roles remain not studied enough in both adult and larval forms of O. felineus. The studies in this area are important in term of the development of a new pharmacological strategy of the struggle with the causative agent of opisthorchiasis affecting the neuronal signal substances and the function of its nervous system.. The aim of this work was the immunocytochemical study of the neurotransmitters serotonin (5-HT, 5-Hydroxitryptamine) and neuropeptide FMRFamide localization in the nervous system of the opisthorchiasis causative agent-O. felineus metacercaria. To study the relationship between the detected neurotransmitters and the muscular elements of the parasite, the muscle staining was carried out simultaneously using fluorophore-conjugated phalloidin.. The localization of 5-HTergic and FMRFamidergic nerve structures was determined by immunocytochemical method. The staining samples were analyzed using a fluorescent and confocal laser scanning microscopies.. The new data on the presence and distribution of the serotonin-immunopositive (IP)- and FMRFa-IP components in the central and peripheral departments of the nervous system of  O. felineus metacercaria has been obtained. Besides that a number of the new anatomical details of the nervous system organization and of the innervation of the organs and tissues in the investigated parasite have been revealed.. The data obtained on the presence and localization of the 5-HTergic and peptidergic (FMRFamide) components in central and peripheral departments of the nervous system of O. felineus metacercaria elaborated and expanded the existing information about the nervous system as well as the innervations of the tissues and organs in the causative agent of opistchorchiasis.

Topics: Animals; Cypriniformes; Fish Diseases; FMRFamide; Immunohistochemistry; Metacercariae; Microscopy, Confocal; Microscopy, Fluorescence; Nervous System; Opisthorchiasis; Opisthorchis; Peptides, Cyclic; Rhodamines; Russia; Serotonin; Staining and Labeling

The structure and organization of the nervous system has been documented for various helminth parasites. However, the neuroanatomy of the carcinogenic liver fluke, Opisthorchis viverrini has not been described. This study therefore investigated the organization of the nervous system of this fluke using cholinesterase activity, aminergic and peptidergic (FMRFamide-like peptides) immunostaining to tag major neural elements. The nervous system, as detected by acetylcholinesterase (AchE) reaction, was similar in newly excysted metacercariae, migrating juveniles and adult parasites. In these stages, there were three pairs (dorsal, ventral and lateral) of bilaterally symmetrical longitudinal nerve cords and two cerebral ganglia. The ventral nerve cords and the cerebral ganglia were well-developed and exhibited strong AchE reactivity, as well as aminergic and FMRFamide-like immunoreactivity. Numerous immunoreactive nerve cell bodies were observed around the inner surface of the ventral sucker. Fine FMRFamide-like peptides immunopositive nerve fiber was rarely observed. Overall, the organization of the nervous system of O. viverrini is similar to other trematodes.

Topics: Acetylcholinesterase; Animals; Cricetinae; Cyprinidae; Fish Diseases; Fluorescent Antibody Technique; FMRFamide; Mesocricetus; Nervous System; Opisthorchis