Network Mechanisms of Spindle-Burst Oscillations in the Neonatal Rat Barrel Cortex In Vivo

• Published in: Journal of neurophysiology Vol. 97; no. 1; pp. 692 - 700
• Main Authors: Minlebaev, Marat, Ben-Ari, Yehezkel, Khazipov, Rustem
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01.01.2007; American Physiological Society
• Subjects: Action Potentials; Action Potentials - drug effects; Action Potentials - physiology; Afferent Pathways; Afferent Pathways - drug effects; Afferent Pathways - growth & development; Animals; Animals, Newborn; Biological Clocks; Biological Clocks - drug effects; Biological Clocks - physiology; Cellular Biology; Excitatory Amino Acid Antagonists; Excitatory Amino Acid Antagonists - pharmacology; Female; GABA Antagonists; GABA Antagonists - pharmacology; GABA-A Receptor Antagonists; gamma-Aminobutyric Acid; gamma-Aminobutyric Acid - metabolism; Glutamic Acid; Glutamic Acid - metabolism; Interneurons; Interneurons - drug effects; Interneurons - metabolism; Life Sciences; Male; Nerve Net; Nerve Net - drug effects; Nerve Net - growth & development; Neural Inhibition; Neural Inhibition - drug effects; Neural Inhibition - physiology; Neuronal Plasticity; Neuronal Plasticity - drug effects; Neuronal Plasticity - physiology; Neurons, Afferent; Neurons, Afferent - drug effects; Neurons, Afferent - physiology; Rats; Rats, Wistar; Receptors, AMPA; Receptors, AMPA - metabolism; Receptors, GABA-A; Receptors, GABA-A - metabolism; Somatosensory Cortex; Somatosensory Cortex - drug effects; Somatosensory Cortex - growth & development; Synaptic Transmission; Synaptic Transmission - drug effects; Synaptic Transmission - physiology; Trigeminal Nerve; Trigeminal Nerve - drug effects; Trigeminal Nerve - growth & development; Vibrissae; Vibrissae - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.00759.2006

The Mediterranean Institute of Neurobiology, Institut National de la Santé et de la Recherche Médicale U29, Université Méditerrenéen, Marseille, France Submitted 21 July 2006; accepted in final form 6 November 2006 Early in development, cortical networks generate particular patterns of activity that participate in cortical development. The dominant pattern of electrical activity in the neonatal rat neocortex in vivo is a spatially confined spindle-burst. Here, we studied network mechanisms of generation of spindle-bursts in the barrel cortex of neonatal rats using a superfused cortex preparation in vivo. Both spontaneous and sensory-evoked spindle-bursts were present in the superfused barrel cortex. Pharmacological analysis revealed that spindle-bursts are driven by glutamatergic synapses with a major contribution of AMPA/kainate receptors, but slight participation of NMDA receptors and gap junctions. Although GABAergic synapses contributed minimally to the pacing the rhythm of spindle-burst oscillations, surround GABAergic inhibition appeared to be crucial for their compartmentalization. We propose that local spindle-burst oscillations, driven by glutamatergic synapses and spatially confined by GABAergic synapses, contribute to the development of barrel cortex during the critical period of developmental plasticity. Address for reprint requests and other correspondence: R. Khazipov, INMED/INSERM U29,163 Avenue de Luminy, B.P. 13, 13273 Marseille, France (E-mail khazipov{at}inmed.univ-mrs.fr )