Persistently active, pacemaker-like neurons in neocortex
- HHMI, Department of Biological Sciences, Columbia University, New York, NY, USA
The neocortex is spontaneously active, however, the origin of this self-generated, patterned activity remains unknown. To detect potential “pacemaker cells,” we use calcium imaging to directly identify neurons that discharge action potentials in the absence of synaptic transmissionin slices from juvenile mouse visual cortex. We characterize 60 of these neurons electrophysiologically and morphologically, finding that they belong to two classes of cells: one class composed of pyramidal neurons with a thin apical dendritic tree and a second class composed of ascending axon interneurons (Martinotti cells) located in layer 5. In both types of neurons, persistent sodium currents are necessary for the generation of the spontaneous activity. Our data demonstrate that subtypes of neocortical neurons have intrinsic mechanisms to generate persistent activity. Like in central pattern generators (CPGs), these neurons may act as “pacemakers” to initiate or pattern spontaneous activity in the neocortex.
Keywords:
CPG, martinotti, persistent sodium, FAP
Citation:
Morgane Le Bon-Jego and Rafael Yuste (2007). Persistently active, pacemaker-like neurons in neocortex. Front. Neurosci. 1:1. 123-129. doi: 10.3389/neuro.01/1.1.009.2007
Received: 15 August 2007; Paper pending published: 01 September 2007;
Accepted: 01 September 2007;
Published online: 15 October 2007.
Edited by:
Idan Segev, Hebrew University, Israel
Reviewed by:
Yosef Yarom, Hebrew University, Israel
Henry Markram, Ecole Polytechnique Federale de Lausanne, Switzerland
Copyright:
© 2007 Le Bon-Jego and Yuste. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Rafael Yuste, Columbia University, Biological Sciences, 1002 Fairchild Center, M.C. 2435, New York, N.Y. 10027.e-mail: rmy5@columbia.edu
aCurrent address:
Universités Bordeaux 2, 1, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5227, Bordeaux, F-33076, France.