Sequential generation of two distinct synapse-driven network patterns in developing neocortex. - Archive ouverte HAL Access content directly
Journal Articles Journal of Neuroscience Year : 2008

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

(1) , (1) , (1) , (1) , (1) , (1) , (1)
1

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.
Fichier principal
Vignette du fichier
AlleneJNeuro2008.pdf (4.87 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

inserm-00483521 , version 1 (14-05-2010)

Identifiers

Cite

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

Collections

INSERM UNIV-AMU
99 View
205 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More