Sequential generation of two distinct synapse-driven network patterns in developing neocortex.

Abstract : Developing cortical networks generate a variety of coherent activity patterns that participate in circuit refinement. Early network oscillations (ENOs) are the dominant network pattern in the rodent neocortex for a short period after birth. These large-scale calcium waves were shown to be largely driven by glutamatergic synapses albeit GABA is a major excitatory neurotransmitter in the cortex at such early stages, mediating synapse-driven giant depolarizing potentials (GDPs) in the hippocampus. Using functional multineuron calcium imaging together with single-cell and field potential recordings to clarify distinct network dynamics in rat cortical slices, we now report that the developing somatosensory cortex generates first ENOs then GDPs, both patterns coexisting for a restricted time period. These patterns markedly differ by their developmental profile, dynamics, and mechanisms: ENOs are generated before cortical GDPs (cGDPs) by the activation of glutamatergic synapses mostly through NMDARs; cENOs are low-frequency oscillations (approximately 0.01 Hz) displaying slow kinetics and gradually involving the entire network. At the end of the first postnatal week, GABA-driven cortical GDPs can be reliably monitored; cGDPs are recurrent oscillations (approximately 0.1 Hz) that repetitively synchronize localized neuronal assemblies. Contrary to cGDPs, cENOs were unexpectedly facilitated by short anoxic conditions suggesting a contribution of glutamate accumulation to their generation. In keeping with this, alterations of extracellular glutamate levels significantly affected cENOs, which are blocked by an enzymatic glutamate scavenger. Moreover, we show that a tonic glutamate current contributes to the neuronal membrane excitability when cENOs dominate network patterns. Therefore, cENOs and cGDPs are two separate aspects of neocortical network maturation that may be differentially engaged in physiological and pathological processes.
Type de document :
Article dans une revue
Journal of Neuroscience, Society for Neuroscience, 2008, 28 (48), pp.12851-63. 〈10.1523/JNEUROSCI.3733-08.2008〉
Liste complète des métadonnées

Littérature citée [65 références]  Voir  Masquer  Télécharger

http://www.hal.inserm.fr/inserm-00483521
Contributeur : Roman Tyzio <>
Soumis le : vendredi 14 mai 2010 - 13:59:17
Dernière modification le : jeudi 1 février 2018 - 15:56:02
Document(s) archivé(s) le : jeudi 16 septembre 2010 - 14:06:44

Fichier

AlleneJNeuro2008.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

Collections

Citation

Camille Allène, Adriano Cattani, James Ackman, Paolo Bonifazi, Laurent Aniksztejn, et al.. Sequential generation of two distinct synapse-driven network patterns in developing neocortex.. Journal of Neuroscience, Society for Neuroscience, 2008, 28 (48), pp.12851-63. 〈10.1523/JNEUROSCI.3733-08.2008〉. 〈inserm-00483521〉

Partager

Métriques

Consultations de la notice

207

Téléchargements de fichiers

144