Cellular and network mechanisms underlying spontaneous sharp wave-ripple complexes in mouse hippocampal slices.
The mammalian hippocampus displays a peculiar pattern of fast (approximately 200 Hz) network oscillations superimposed on slower sharp waves. Such sharp wave-ripple complexes (SPW-R) have been implicated in memory consolidation. We have recently described a novel and unique method for studying SPW-R in naive slices of murine hippocampus. Here, we used this model to analyse network and cellular mechanisms of this type of network activity. SPW-R are usually generated within area CA3 but can also originate within the isolated CA1 region. Cellular synchronisation during SPW-R requires both excitatory and inhibitory synaptic transmission as well as electrical coupling, the latter being particularly important for the high-frequency component. Extracellular and intracellular recordings revealed a surprisingly strong inhibition of most CA1 pyramidal cells during SPW-R. A minority of active cells, however, increases action potential frequency and fires in strict synchrony with the field ripples. This strong separation between members and non-members of the network may serve to ensure a high signal-to-noise ratio in information processing during sharp wave-ripple complexes.
Maier
Nikolaus
N
Johannes-Müller-Institut für Physiologie der Charité, Tucholskystrasse 2, 10117 Berlin, Germany.
Nimmrich
Volker
V
Draguhn
Andreas
A
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D004569:Electroencephalography; D004594:Electrophysiology; D005110:Extracellular Space / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D017629:Gap Junctions / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology; D011724:Pyridazines / Q000494:pharmacology; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D013569:Synapses / Q000502:physiology; D014475:Uncoupling Agents / Q000494:pharmacology
D018756:GABA Antagonists; D058787:GABA-A Receptor Antagonists; D011724:Pyridazines; D018091:Receptors, AMPA; D014475:Uncoupling Agents; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; C049853:gabazine