1.FMRFamide enhances acetylcholine-induced contractions of guinea pig ileum.
Raffa RB;Jacoby HI Peptides. 1989 May-Jun;10(3):693-5.
Isolated guinea pig ilea were contracted with acetylcholine (ACh) in the absence and presence of the neuropeptide FMRFamide (Phe-Met-Arg-Phe-NH2). FMRFamide (0.17-17 microM) enhanced ACh-induced contractions (observed as a leftward shift of the dose-response curve and increase in Emax) with maximal effect at 1.7 microM. FMRFamide had no effect when administered alone. These results extend the demonstration of a FMRFamide/ACh interaction to mammalian tissue and support the concept that FMRFamide, or mammalian equivalents, could play a modulatory role in mammals.
2.Bulbus arteriosus of the bivalve mollusc Mercenaria mercenaria: Morphology and pharmacology.
Deaton LE;Felgenhauer BE;Duhon DW J Morphol. 2001 Nov;250(2):185-95.
We examined the morphology and pharmacology of the bulbus arteriosus of the marine bivalve mollusc Mercenaria mercenaria. The bulbus arteriosus is an organ of unknown function associated with the posterior aorta and the ventricle. It is composed of connective tissue interspersed with muscle bundles. In contrast to the lumen of the ventricle, which has an extensive trabecular network, the lumen of the bulbus arteriosus has no trabeculae. No valve is present in the posterior aorta connecting the lumina of the ventricle and the bulbus arteriosus. Scattered neuronal profiles are present in the wall and the axonal processes contain vesicles that may contain neurosecretory products. We did not, however, find synapses or evidence of vesicular release into the lumen of the bulbus arteriosus. The bulbus arteriosus contains acetylcholine, 5-hydroxytryptamine (5HT), and the molluscan neuropeptides FMRFamide (phenyl-alanyl-methionyl-arginyl-phenylalaninylamide) and FLRFamide (phenylalanyl-leucinyl-arginyl-phenylalanylamide). The isolated bulbus arteriosus contracts tonically in response to mechanical stress and exposure to 5HT or FMRFamide, while acetylcholine relaxes it. We surmise that the bulbus arteriosus probably functions as a mechanism for regulating the relative amounts of hemolymph pumped into the anterior and posterior aortae by the ventricle and that the bulbus arteriosus may be a neurohemal site.
3.Neuronal Development in the Larvae of the Invasive Biofouler Dreissena polymorpha (Mollusca: Bivalvia), with Special Attention to Sensory Elements and Swimming Behavior.
Battonyai I;Voronezhskaya EE;Obukhova A;Horváth R;Nezlin LP;Elekes K Biol Bull. 2018 Jun;234(3):192-206. doi: 10.1086/698511. Epub 2018 Jun 18.
Although understanding of the neuronal development of Trochozoa has progressed recently, little attention has been paid to freshwater bivalves, including species with a strong ecological impact, such as the zebra mussel (Dreissena polymorpha). Therefore, an important question might concern how the developing nervous system is involved in the formation of the rapid and successful invasive behavior of this species. Our aim was to reveal the neuronal development of trochophore and veliger larvae of Dreissena, with special attention to the organization of sensory structures and their possible involvement in detecting environmental cues. After applying serotonin and FMRFamide immunocytochemistry, the first serotonin immunoreactive sensory elements appeared 16-18 hours after fertilization, whereas the first FMRFamide immunoreactive sensory cell was seen only at 32 hours of development (trochophore stage). Later, sensory elements were found in three parts of the larval body, including the apical organ, the posterior region, and the stomach. Although differences in the timing of appearance and the morphology of cells were observed, the two signaling systems showed basic similarity in their organization pattern until the end of the veliger stage.
