Simulation of Spontaneous Activity Generation in an Excitatory Network Involved in the Control of the Respiratory Rhythm

  • Joël Pham
  • Khashayar Pakdaman
  • Jean-Francois Vibert


Some neural circuits of the brainstem display a spontaneous activity even when they are isolated from their afferences (Bennett and St. John 1985, Ezure 1990). Such a spontaneous activity, related to the control of the respiratory rhythm, was observed by Fortin & Champagnat (1993) in slices of rat brainstem at the level of the Nucleus Tractus Solitarius (NTS). This spontaneous activity had a low frequency (10 to 15 synaptic events per second) and was generated by a network consisting of neurons connected only by excitatory connections. No pacemaker units were observed in this network. Fortin and Champagnat noted that Excitatory Post-Synaptic Potentials (EPSPs) were still occurring in the presence of tetrodotoxin (TTX), though action potentials were no longer generated in the cells, but with a lower frequency (1 to 1.5 EPSP per second). Fortin and Champagnat hypothesized that the spontaneous activity displayed by the brainstem slices was the result of the amplification by the excitatory connections of the low frequency background synaptic activity observed in the presence of TTX.


Spontaneous Activity Nucleus Tractus Solitarius Spike Rate Respiratory Rhythm Excitatory Connection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Bennett F.M., St-John W.M. (1985) Function in ventilatory control of respiratory neurons at the pontomedullary junction. Respir. Physiol. 61, 153–166.PubMedCrossRefGoogle Scholar
  2. [2]
    Ezure K. (1990) Synaptic connections between medullary respiratory neurons and considerations on the genesis of respiratory rhythm. Prog. Neurobiol. 35, 429–450.PubMedCrossRefGoogle Scholar
  3. [3]
    Fortin G., Champagnat J. (1993) Spontaneous synaptic activities in rat nucleus tractus solitarius neurons in vitro. Brain Res. 630, 125–135.PubMedCrossRefGoogle Scholar
  4. [4]
    Van Ooyen A. and Van Pelt J. (1992) The emergence of long-lasting transients of activity in simple neural networks. Biol. Cyber 67, 269–277.CrossRefGoogle Scholar
  5. [5]
    Vibert J.-F., Pakdaman K., Cloppet F. and Azmy N. (1994). NBC: a workstation for biological neural network simulation. In Skrzypek J (Eds) Neural Network Simulation Environments, 113–132. Kluwer Academic Publishers, Boston (USA).CrossRefGoogle Scholar
  6. [6]
    Vibert J.-F., Pham J., Pakdaman K. and Azmy N. (1995). XNBC: a simulation tool for neurobiologists. In: The neurobiology of computation. J. Bower Ed. Kluwer Academic Pub., Boston (USA).Google Scholar
  7. [7]
    Vibert J.-F., Pakdaman K., Boussard E., Av-Ron E. (1997) XNBC: a simulation tool. Application to the study of neural coding using hybrid networks. Bio Systems 40, 211–218.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • Joël Pham
    • 1
  • Khashayar Pakdaman
    • 1
  • Jean-Francois Vibert
    • 1
  1. 1.B3E, ESI, INSERM U444, ISARS, Faculté de Médecine Saint-AntoineUniversité Pierre and Marie Curie, Paris VI.Paris Cedex 12France

Personalised recommendations