Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-27T11:26:23.359Z Has data issue: false hasContentIssue false
  • English
  • Français

Characterization of identifiable neurones in the head ganglia of the parasitic nematode Ascaris suum: a comparison with central neurones of Caenorhabditis elegans

Published online by Cambridge University Press:  06 April 2009

L. Holden-Dye  and
R. J. Walker
L. Holden-Dye
Affiliation:
Department of Physiology and Pharmacology, Bassett Crescent East, University of Southampton, Southampton SO9 3TU
R. J. Walker
Affiliation:
Department of Physiology and Pharmacology, Bassett Crescent East, University of Southampton, Southampton SO9 3TU
Get access Rights & Permissions [Opens in a new window]

Summary

Intracellular recordings have been made from neurones in the head ganglia of Ascaris. The neurones had low resting membrane potentials of –21±9 mV (n = 78) and a relatively high input resistance (e.g. 25 MΩ for a 100 μm cell). In all cases the intracellular location of the recording electrode was verified by injection of the fluorescent marker, 5, 6-carboxyfluorescein (CBXF). To ascertain whether or not the low membrane potential was due to impalement damage, the same neurone was recorded from using two microelectrodes. The membrane potential following the first impalement by a 20 MΩ 3 M KCl electrode was –38 mV and following the second impalement by a 80 MΩ CBXF (for subsequent intracellular labelling) electrode was decreased to –34 mV. Input resistance of these cells was estimated using both single and two electrode intracellular recording techniques and in both cases yielded a relatively high value for the size of cell (e.g. 25 MΩ for a 100 μm cell). Neurones labelled by intracellular injection of the fluorescent marker 5, 6-carboxy-fluorescein were morphologically simple and lacked extensive arborizations. The dorsal ganglion is a discrete structure consisting of only 3 neurones. Here we compare the morphological properties of these neurones to those described in the dorsal ganglion of Caenorhabditis elegans. The whole mount preparation of Ascaris ganglia thus provides a useful model to study the functional properties of neurones in nematode central nervous system and presents the possibility to assess central sites of action for anthelmintics.

Keywords

Ascaris suumCaenorhabditis eleganscentral neurones
Type
Research Article
Information
Parasitology , Volume 108 , Issue 1 , January 1994 , pp. 81 - 87
Copyright
Copyright © Cambridge University Press 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Angstadt, J. D., Donmoyer, J. E. & Stretton, A. O. W. (1989). Retrovesicular ganglion of the nematode Ascaris. Journal of Comparative Neurology 284, 374–88.CrossRefGoogle ScholarPubMed
Davis, R. E. & Stretton, A. O. W. (1989a). Passive membrane properties of motoneurones and their role in long-distance signalling in the nematode Ascaris. Journal of Neuroscience 9, 403–14.CrossRefGoogle ScholarPubMed
Davis, R. E. & Stretton, A. O. W. (1989b). Signalling properties of Ascaris motoneurons: graded active responses, graded synaptic transmission, and tonic transmitter release. Journal of Neuroscience 9, 415–25.CrossRefGoogle ScholarPubMed
Goldschmidt, R. (1908). Das Nervensystem von Ascaris lumbricoides und Megalocephala. Zeitschrift für wissenschaftliche Zoologie 90, 73–136.Google Scholar
Stretton, A. O. W., Davis, R. E., Angstadt, J. D., Donmoyer, J. E. & Johnson, C. D. (1985). Neural control of behaviour in Ascaris. Trends in Neurosciences 8, 294–300.CrossRefGoogle Scholar
Sulston, J., Du, Z., Thomas, K., Wilson, R., Hillier, L., Staden, R., Halloran, N., Green, P., Thiery-Mieg, J., Qui, L., Dear, S., Coulson, A., Craxton, M., Durbin, R., Berks, M., Metzstein, M., Hawkins, T., Ainscough, R. & Waterson, R. (1992). The C. elegans genome sequencing project: a beginning. Nature 356, 37–40.CrossRefGoogle Scholar
Walrond, J. P., Kass, I. S., Stretton, A. O. W. & Donmoyer, J. E. (1985). Identification of excitatory and inhibitory motorneurons in the nematode Ascaris by electrophysiological techniques. ournal of Neuroscience 5, 1–8.Google Scholar
White, J. E., Southgate, E., Thompson, J. N. & Brenner, S. (1976). The structure of the ventral nerve cord of Caenorhabditis elegans. Philosophical Transactions of the Royal Society London (Biology) 275, 327–48.Google ScholarPubMed
White, J. G. E., Southgate, E., Thompson, J. N. & Brenner, S. (1986). The Structure of the nervous system of Caenorhabditis elegans. Philosophical Transactions of the Royal Society London (Biology) 314, 1–340.Google ScholarPubMed