Skip to content

Research at St Andrews

Cloning and expression of a FMRFamide-gated Na+ channel from Helisoma trivolvis and comparison with the native neuronal channel

Research output: Contribution to journalArticlepeer-review


Glen Alfred Cottrell, MC Jeziorski, KA Green, John Sommerville

School/Research organisations


1. We have cloned a cDNA encoding a Phe:-Met-Arg-Phe-:NH2 (FMRFamide)-gated Na+ channel from nervous tissue of the pond snail Helisoma trivolvis (HtFaNaC) and expressed the channel in Xenopus oocytes. The deduced amino acid sequence of the protein expressed by HtFaNaC is 65 % identical to that of the FMRFamide-gated channel cloned fr om Helix aspersa (HaFaNaC).

2. HtFaNaC expressed in oocytes was less sensitive to FMRFamide (EC50 = 70 mu M) than HaFaNaC (EC50 = 2 mu M). The two had a similar selectivity for Naf. The amplitude of the FMRFamide response of HtFaNsC was increased by reducing the extracellular concentration of divalent cations.

3. The conductance of the two channels was similar, but the mean open time of unitary events was shorter for expressed HtFaNaC compared to expressed HaFaNaC. Each channel was susceptible to peptide block by high agonist concentrations.

4. In marked contrast to HaFaNaC and other amiloride-sensitive Na+ channels, amiloride, and the related drugs benzamil and 5- (N-ethyl-N-isopropyl)-amiloride (EIPA), enhanced the FMRFamide response in oocytes expressing HtFaNaC cRNA. The potentiating effects of EIPA and benzamil were greater than those of amiloride. Unitary current analysis showed that with such drugs, there was channel blockade as well as an increased probability of channel opening.

5. The similar permeability of the oocyte-expressed HtFaNaC and the Helisoma neuronal channel, and the susceptibility of both to agonist blockade and blockade by divalent cations, suggest that the channels are the same. However, neuronal channels were less susceptible to enhancement by amiloride analogues and in some patches were more sensitive to FMRFamide than expressed HtFaNaC.



Original languageEnglish
Pages (from-to)13-25
Number of pages13
JournalThe Journal of Physiology
Issue number1
Publication statusPublished - 1 Jul 2000

    Research areas


Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Fast silencing reveals a lost role for reciprocal inhibition in locomotion

    Moult, P. R., Cottrell, G. A. & Li, W., 9 Jan 2013, In: Neuron. 77, 1, p. 129-140 12 p.

    Research output: Contribution to journalArticlepeer-review

  2. Green laser light (532nm) activates a chloride current in the C1 neuron of Helix aspersa

    Reece, P. J., Dholakia, K., Thomas, R. C. & Cottrell, G. A., 15 Mar 2008, In: Neuroscience Letters. 433, 3, p. 265-269 5 p.

    Research output: Contribution to journalArticlepeer-review

  3. Green light activates some and inhibits other neurons of snail ganglia

    Reece, P. J., Dholakia, K. & Cottrell, G. A., 2007, Acta Physiologica Supplement.

    Research output: Book/ReportBook

  4. Dynamic regulation of histone modifications in Xenopus oocytes through histone exchange.

    Stewart, MD., Sommerville, J. & Wong, J., Sep 2006, In: Molecular and Cellular Biology. 26, 18, p. 6890-6901 12 p.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. A simple decision to move in response to touch reveals basic sensory memory and mechanisms for variable response times

    Koutsikou, S., Merrison-Hort, R., Buhl, E., Ferrario, A., Li, W-C., Borisyuk, R., Soffe, S. R. & Roberts, A., 15 Dec 2018, In: The Journal of Physiology. 596, 24, p. 6219-6233

    Research output: Contribution to journalArticlepeer-review

  2. Exploring the biophysical evidence that mammalian two pore channels are NAADP-activated calcium-permeable channels

    Pitt, S. J., Reilly O'Donnell, B. & Sitsapesan, R., 1 Aug 2016, In: The Journal of Physiology. 594, 15, p. 4171-4179 9 p.

    Research output: Contribution to journalReview articlepeer-review

  3. The role of internal and external constructive processes in evolution

    Laland, K. N., Odling-Smee, F. J. & Turner, S., 2014, In: The Journal of Physiology. 592, 11, p. 2413-2422

    Research output: Contribution to journalArticlepeer-review

  4. Ca2+ transients in myenteric glial cells during the colonic migrating motor complex in the isolated murine large intestine

    Broadhead, M. J., Bayguinov, P., Okamoto, T., Heredia, D., Hennig, G. & Smith, T., 2012, In: The Journal of Physiology.

    Research output: Contribution to journalArticlepeer-review

  5. Bestrophin expression and function in the human pancreatic duct cell line, CFPAC-1

    Marsey, L. L. & Winpenny, J. P., 15 May 2009, In: The Journal of Physiology. 587, Pt 10, p. 2211-24 14 p.

    Research output: Contribution to journalArticlepeer-review

ID: 172914