Nematocyst discharge in Hydra vulgaris: Differential responses of desmonemes and stenoteles to mechanical and chemical stimulation

Scappaticci, A. A.; Kahn, Fhyzeedon; Kass-Simon, G.

doi:10.1016/j.cbpa.2010.06.177

Cited by 24 publications

(14 citation statements)

References 32 publications

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“…The present study confirms the role of mucin, a glycosylated protein, in activating discharge in nematocytes, already demonstrated in cnidarians, due to the sugar moiety activating specific receptors in tentacles (Scappaticci et al 2010). Our results, in accordance with the latter authors, show that low-concentrated mucin (10 -5 M) induces a notable discharge response.…”

Section: Proteinssupporting

confidence: 95%

“…Mucus has also been recognized as an inhibitor of nematocyst discharge in sea anemone and clownfish interaction (Lubbock 1979) and in sea anemone and nudibranch interaction (Mauch and Elliott 1997;Greenwood et al 2004). Mucin, or a similar prey-produced molecule, could be used at one set of concentrations to act as a nematocystsensitizing agent, and, at higher concentrations, as an inhibitor, which might contribute to the feeding-satiety control mechanisms in hydra ( Thorington and Hessinger 1988;Scappaticci et al 2010). Our results could confirm this role of mucin.…”

Section: Proteinsmentioning

confidence: 98%

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Nematocytes’ activation in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms

Morabito

Marino²,

Spada³

2012

J Comp Physiol A

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Nematocytes' discharge is triggered to perform both defense and predation strategies in cnidarians and occurs under chemico-physical stimulation. In this study, different compounds such as amino acids and proteins (mucin, albumin, poly-L: -lysine, trypsin), sugars and N-acetylate sugars (N-acetyl neuraminic acid, N-acetyl galactosamine, sucrose, glucose, agarose and trehalose), nucleotides (ATP and cAMP), were tested as chemosensitizers of nematocyte discharge in the oral arms of the scyphozoan Pelagia noctiluca, particularly abundant in the Strait of Messina (Italy). Excised oral arms were submitted to a combined chemico-physical stimulation by treatment with different compounds followed by mechanical stimulation by a non-vibrating test probe. Discharge induced by a chemico-physical stimulation was more significant than that obtained after mechanical stimulation alone. A chemosensitizing mechanism, with a dose-dependent effect, was observed after treatment with sugars, amino compounds such as glutathione, nucleotides and mucin, according to that already seen in sea anemones. Such findings suggest that, though Anthozoa and Scyphozoa exhibit different divergence times during the evolutionary process, the discharge activation exhibits common features, probably derived from their last common ancestor.

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Section: Proteinssupporting

confidence: 95%

Section: Proteinsmentioning

confidence: 98%

Nematocytes’ activation in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms

Morabito

Marino²,

Spada³

2012

J Comp Physiol A

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“…More recently, immunohistochemistry studies have demonstrated that glutamate and GABA exist in the nerve plexus within the tentacles of a sea anemone Phymactis papillosa, suggesting that glutamate and GABA function as neuronal signalling molecules in the primitive nervous system of cnidarians (Delgado et al, 2010). Furthermore, GABA receptors modulate the discharge of nematocysts in hydra (Scappaticci et al, 2010;Scappaticci and Kass-Simon, 2008). Nematocysts, which are also called cnidae, are sophisticated stinging cells found in all cnidarians and are required for prey capture and defence mechanisms (Beckmann and Özbek, 2012).…”

Section: Single-pass Membrane Proteins -A Possible Interaction Partnementioning

confidence: 99%

The role of G protein-coupled receptors in the early evolution of neurotransmission and the nervous system

Krishnan

Schiöth

2015

Journal of Experimental Biology

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The origin and evolution of the nervous system is one of the most intriguing and enigmatic events in biology. The recent sequencing of complete genomes from early metazoan organisms provides a new platform to study the origins of neuronal gene families. This review explores the early metazoan expansion of the largest integral transmembrane protein family, the G protein-coupled receptors (GPCRs), which serve as molecular targets for a large subset of neurotransmitters and neuropeptides in higher animals. GPCR repertories from four pre-bilaterian metazoan genomes were compared. This includes the cnidarian Nematostella vectensis and the ctenophore Mnemiopsis leidyi, which have primitive nervous systems (nerve nets), the demosponge Amphimedon queenslandica and the placozoan Trichoplax adhaerens, which lack nerve and muscle cells. Comparative genomics demonstrate that the rhodopsin and glutamate receptor families, known to be involved in neurotransmission in higher animals are also widely found in prebilaterian metazoans and possess substantial expansions of rhodopsin-family-like GPCRs. Furthermore, the emerging knowledge on the functions of adhesion GPCRs in the vertebrate nervous system provides a platform to examine possible analogous roles of their closest homologues in pre-bilaterians. Intriguingly, the presence of molecular components required for GPCR-mediated neurotransmission in pre-bilaterians reveals that they exist in both primitive nervous systems and nerve-cell-free environments, providing essential comparative models to better understand the origins of the nervous system and neurotransmission. KEY WORDS: Neuron, GPCR, Nerve net, Synapse, EvolutionIntroduction G protein-coupled receptors (GPCRs) constitute the largest superfamily among membrane bound proteins that control key physiological functions, such as, neurotransmission, hormone releases, and immune responses among others (Katritch et al., 2013; Lagerström and Schiöth, 2008;Rosenbaum et al., 2009). As such, the large range of integral transmembrane proteins in this family respond to subsequent, diverse array of ligands: including neurotransmitters, hormones, lipids, and odorants (Civelli et al., 2013;Shoichet and Kobilka, 2012). GPCRs in mammals are classified into the five main families according to the GRAFS classification: glutamate, rhodopsin, adhesion, frizzled and secretin (Fredriksson et al., 2003). These five GPCR families are associated with various physiological functions, but the roles of the glutamate and the rhodopsin families are particularly well documented for REVIEW Department of Neuroscience, Functional Pharmacology, Uppsala University, BMC, Box 593,751 24, Uppsala, Sweden.*Authors for correspondence (arunkumar.krishnan@neuro.uu.se; helgi.schioth@neuro.uu.se) neurotransmission and regulation of the nervous system (Niswender and Conn, 2010;Schoepp, 2001). Some functions include synaptic transmission, synapse formation, axon guidance and development of neuronal circuits (Collingridge et al., 2004;Hnasko and Edwards, 2012)...

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“…Is it possible that these contact-sensitive mechanoreceptors also are influenced by activated chemoreceptors? In hydra, the answer to this question is ‘yes.’ It was determined in Hydra vulgaris that test probes contacting the cnidocils (modified cilia arising from cnidocytes) trigger nematocyst discharge in a force-dependent fashion (Scappaticci et al, 2010). Here, a piezo bimorph driven by a stimulator delivered impacts to cnidocils over a range of forces depending on the voltage applied to the bimorph.…”

Section: Introductionmentioning

confidence: 99%

Force-dependent discharge of nematocysts in the sea anemone Haliplanella luciae (Verrill)

Todaro

Watson

2012

Biology Open

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SummarySea anemones discharge cnidae (‘stinging capsules’ including nematocysts) to capture prey and to defend themselves. In the present study, we tested the relationship between the force of test probes striking feeding tentacles and discharge of microbasic p-mastigophore nematocysts into the test probes. In seawater alone, the response curve is bimodal with maximal discharge observed at 0.33 and 1.10 millinewtons (mN) and with minimal discharge at 1.50 mN. Upon activating chemoreceptors for N-acetylated sugars, maximal discharge is observed across a broad range of smaller forces from 0.16 to 0.9 mN before decreasing to a minimum at 1.50 mN. Likewise, in the presence of nearby vibrations at key frequencies, maximal discharge is observed over a broad range of smaller forces before decreasing to a minimum at 1.50 mN. It appears that sensory input indicating proximity of potential prey expands the range of small forces of impact that stimulate maximal discharge (i.e. to less than 1.10 mN) but not at larger forces of impact (i.e. at approximately 1.50 mN). Thus, contact by small prey would stimulate maximal discharge, and all the more so if such contact is accompanied by specific odorants or by vibrations at specific frequencies. Nevertheless, anemones would not maximally discharge nematocysts into large animals that blunder into contact with their tentacles.

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Nematocyst discharge in Hydra vulgaris: Differential responses of desmonemes and stenoteles to mechanical and chemical stimulation

Cited by 24 publications

References 32 publications

Nematocytes’ activation in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms

Nematocytes’ activation in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms

The role of G protein-coupled receptors in the early evolution of neurotransmission and the nervous system

Force-dependent discharge of nematocysts in the sea anemone Haliplanella luciae (Verrill)

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