Biological Cybernetics

, Volume 83, Issue 1, pp 1–20

The dynamics of a neuronal culture of dissociated cortical neurons of neonatal rats


  • Yasuhiko Jimbo
    •  NTT Basic Res. & Telephone Co., 3-1, Morinosato Wakamiya, Atsugi-Shi, Kanagawa Pref., 243-01, Japan
  • Akio Kawana
    •  NTT Basic Res. & Telephone Co., 3-1, Morinosato Wakamiya, Atsugi-Shi, Kanagawa Pref., 243-01, Japan
  • Pietro Parodi
    •  INFM, Via Beirut 2-4, 34014 Trieste, Italy
  • Vincent Torre
    •  INFM, Via Beirut 2-4, 34014 Trieste, Italy

DOI: 10.1007/PL00007970

Cite this article as:
Jimbo, Y., Kawana, A., Parodi, P. et al. Biol Cybern (2000) 83: 1. doi:10.1007/PL00007970


Neuronal networks of dissociated cortical neurons from neonatal rats were cultured over a multielectrode dish with 64 active sites, which were used both for recording the electrical activity and for stimulation. After about 4 weeks of culture, a dense network of neurons had developed and their electrical activity was studied. When a brief voltage pulse was applied to one extracellular electrode, a clear electrical response was evoked over almost the entire network. When a strong voltage pulse was used, the response was composed of an early phase, terminating within 25 ms, and a late phase which could last several hundreds of milliseconds. Action potentials evoked during the early phase occurred with a precise timing with a small jitter and the electrical activity initiated by a localized stimulation diffused significantly over the network. In contrast, the late phase was characterized by the occurrence of clusters of electrical activity with significant spatio-temporal fluctuations. The late phase was suppressed by adding small amounts of d(−)-2-amino-5-phosphonovaleric acid to the extracellular medium, or by increasing the amount of extracellular Mg2+. The electrical activity of the network was substantially increased by the addition of bicuculline to the extracellular medium. The results presented here show that the neuronal network may exist in two different dynamical states: one state in which the neuronal network behaves as a non-chaotic deterministic system and another state where the system exhibits large spatio-temporal fluctuations, characteristic of stochastic or chaotic systems.

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© Springer-Verlag Berlin Heidelberg 2000