Membrane potential oscillations in molluscan "burster" neurones

Research output: Contribution to journalArticle (Academic Journal)peer-review

34 Citations (Scopus)

Abstract

Membrane potential oscillations can be induced in molluscan neurones under a variety of artificial conditions. In the so-called 'burster' neurones oscillations are generated even in isolated cells. A likely mechanism for 'bursting' involves the following ionic currents: 1. A transient inward current carried by Na+ and Ca2+. This current is responsible for the upstroke of the action potentials. 2. A delayed outward current carried by K+. This current is voltage-sensitive and is responsible for the downstroke of the action potential during the early part of the burst. It becomes progressively inactivated during the burst. Its amplitude depends on the intracellular pH. 3. A rapidly developing outward current carried by K+ which is inactivated at potentials close to action potential threshold. This current tends to hold the membrane in the hyperpolarized state and is involved in spacing the action potentials. 4. A prolonged inward current which may not inactivate. It is probably carried by both Na+ and Ca2+. This current is responsible for the depolarizing phase of the burst but also contributes to the action potential. 5. A slowly developing outward current, carried by K+. This current appears as a result of a slow increase in intracellular ionized calcium and is responsible for the hyperpolarizing phase of the burst. Note that a transient increase in this current may also contribute to the falling phase of the action potential during the later stages of the burst. It is also sensitive to intracellular pH. One of the more significant features of this system of producing membrane potential oscillations is that the frequency of the bursts depends on the rate at which the intracellular ionized calcium returns to its resting level. This process depends on the metabolic state of the animal which can thereby exert a considerable influence on the electrical activity of burster neurones.

Original languageEnglish
Pages (from-to)93-112
Number of pages20
JournalJournal of Experimental Biology
Volume81
Publication statusPublished - Aug 1979

Keywords

  • Animals
  • Aplysia
  • Calcium
  • Helix (Snails)
  • Hydrogen-Ion Concentration
  • Membrane Potentials
  • Neurons
  • Periodicity
  • Permeability
  • Potassium
  • Protons

Fingerprint Dive into the research topics of 'Membrane potential oscillations in molluscan "burster" neurones'. Together they form a unique fingerprint.

Cite this