Persistently active, pacemaker-like neurons in neocortex.

1. Front Neurosci. 2007 Oct 15;1(1):123-9. doi: 10.3389/neuro.01.1.1.009.2007.
eCollection 2007 Nov.

Persistently active, pacemaker-like neurons in neocortex.

Le Bon-Jego M(1), Yuste R.

Author information:
(1)HHMI, Department of Biological Sciences, Columbia University New York, NY
10027, 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.

DOI: 10.3389/neuro.01.1.1.009.2007
PMCID: PMC2518052
PMID: 18982123

Know more about