An immunocytochemical study of putative neurotransmitters in the metacercariae of two strigeoid trematodes from rainbow trout (Oncorhynchus mykiss)

Abstract

Whole mounts of the metacercariae of Diplostomum sp. and Cotylurus erraticus from rainbow trout have been treated cytochemically for the demonstration of cholinergic, serotoninergic (5-hydroxytryptamine) and peptidergic elements in the nervous system. Antisera directed against four vertebrate (pancreatic polypeptide, peptide YY, substance P and peptide histidine isoleucine) and two invertebrate peptides (neuropeptide F and FMRFamide) were used in an indirect immunofluorescence procedure in conjunction with confocal scanning laser microscopy (CSLM). Of the seven antisera tested, all except peptide histidine isoleucine showed significant immunoreactivity. Cholinergic and serotoninergic staining was found primarily in the central nervous system (CNS) and in cell bodies associated with the ventral and dorsal nerve cords in both trematodes. Peptidergic immunoreactivity was localised in the CNS and PNS of both genera, revealing an extensive innervation within the holdfast organ and in and around the oral and ventral suckers.

The spatial relationship between the musculature and the 5-HT and FMRFamide immunoreactivities in cercaria, metacercaria and adult Opisthorchis felineus (Digenea)

“…The FMRFamide IR nerve fibres are also more widely expressed than the 5-HT IR nerve fibres. Similar patterns have been obtained in D. spathaceum, C. erraticus, Apatemon cobitidis proterorhini, Bucephaloides gracilescens and E. caproni (Barton et al 1993;Stewart et al 2003a, b;Šebelová et al 2004). According to Halton and Gustafsson (1996) the aminergic and peptidergic pathways are quite separate and distinctive in construction.…”

“…5-HT is generally regarded as the main excitatory neurotransmitter of motor activity in flatworms (see Halton and Maule 2004). The pattern of 5-HT IR neurones in cercariae of O. felineus is similar to those in cercariae of Cryptocotyle lingua, Cercariae emasculans (Pan et al 1994), E. caproni (Šebelová et al 2004) and metacercariae of D. spathaceum and Cotylurus erraticus (Barton et al 1993). The presence of two 5-HT IR neurones in the tail of cercariae has been reported from a. o. Diplostomum chromatophorum (Terenina and Gustafsson 2003b), E. caproni (Šebelová et al 2004) and Echinoparyphium aconiatum (Terenina et al 2006).…”

The musculature and associated innervation of adult and intramolluscan stages of Echinostoma caproni (Trematoda) visualised by confocal microscopy

“…5B, D), in common with other trematode metacercariae examined, namely, Diplostomum spathaceum, Cotylurus erraticus, Apatemon cobitidis proterorhini and Bucephaloides gracilescens (Barton et al 1993;Stewart et al 2003aStewart et al , 2003b. However, differences in the levels of immunostaining for 5-HT and FaRP were found in E. caproni metacercariae, in that FaRP-immunoreactive nerve elements were comparatively weaker than those staining for 5-HT, and, moreover, were significantly less intense than those observed in the cercaria.…”

The organization of the muscular system and the distribution of NO-ergic and serotoninergic elements of trematodes Allocreadium isoporum Looss, 1894 (Allocreadiidae) and Paramphistomum cervi Zeder, 1790 (Paramphistomatidae)

“…Ïðèìåíåíèå ãèñòîõèìè÷åñêèõ è èììó-íîöèòîõèìè÷åñêèõ ìåòîäîâ ïîçâîëèëî âûÿâèòü â íåðâíîé ñèñòåìå ãåëüìèíòîâ õîëè-íåðãè÷åñêèå, ñåðîòîíèíåðãè÷åñêèå, ïåïòè-äåðãè÷åñêèå ýëåìåíòû (Øèøîâ, 1991;Barton et al, 1993;Biserova et al, 1996;Biserova et al, 2000;Gzubaj, Grabda-Kazubska, 1993;Marks et al, 1995;Niewiadomska et al, 1996 è äð.). Îòêðûòèå ôóíêöèè îêñèäà àçîòà êàê àòèïè÷íîãî íåéðîíàëüíîãî ìåññåíäaeåðà â íåðâíîé ñèñòåìå ìëåêîïèòàþùèõ (Garthwaite, 1991;Snyder, 1992) äàëî òîë÷îê ê èññëåäîâàíèþ ýòîãî âåùåñòâà íå òîëüêî ó ìëåêîïèòàþùèõ, íî è ó äðóãèõ aeèâîòíûõ, â òîì ÷èñëå è áåñïîçâîíî÷íûõ.…”