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Motor coordination without action potentials in the mammalian spinal cord

Nature Neuroscience volume 3, pages 593–599 (2000)Cite this article

Abstract

Coordination of neuronal activity to produce movement is generally thought to depend on spike activity in premotor interneuronal networks. Here we show that even without such activity, the neonatal rat spinal cord could produce a stable motor rhythm mediated by the synchronization of motor neuron oscillations across gap junctions. These rhythms, however, were not coordinated between motor pools in different parts of the spinal cord. We further showed that neural coordination through gap junctions contributed to the fundamental organization and function of spinal motor systems. These results suggest that neural coordination across gap junctions is important in motor-pattern generation in the mammalian spinal cord.

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Figure 1: Rhythmic motor patterning without action potential-dependent chemical synapses.
Figure 2: Coordinated motor rhythms after action potential blockade by TTX.
Figure 3: Interactions between intrinsic oscillations and coordinated network activity in the presence of TTX.
Figure 4: Network coordination in the absence of action potentials is mediated by gap junctions.
Figure 5: TTX-resistant motor rhythm requires NMDA-dependent intrinsic oscillations.
Figure 6: Ventral root oscillations produced in different segments and effects of gap junction blockade on normal locomotion.

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Acknowledgements

This work was supported by the Danish Medical Research Council and the Novo Foundation. M.C.T. is a Postdoctoral Research Fellow supported by the Lundbeck Foundation. We thank Emilio Bizzi, Jorn Hounsgaard, Henrik Jahnsen and Jean-Francois Perrier for reading the manuscript and Hiroshi Nishimaru for suggesting the use of carbenoxolone.

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  1. Department of Physiology, Section of Neurophysiology, The Panum Institute, Blegdamsvej 3, Copenhagen N, 2200, Denmark

    Matthew C. Tresch & Ole Kiehn

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Correspondence to Ole Kiehn.

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Tresch, M., Kiehn, O. Motor coordination without action potentials in the mammalian spinal cord. Nat Neurosci 3, 593–599 (2000). https://doi.org/10.1038/75768

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