title: Impact of spikelets on hippocampal CA1 pyramidal cell activity during spatial exploration.
abstract: In vivo intracellular recordings of hippocampal neurons reveal the occurrence of fast events of small amplitude called spikelets or fast prepotentials. Because intracellular recordings have been restricted to anesthetized or head-fixed animals, it is not known how spikelet activity contributes to hippocampal spatial representations. We addressed this question in CA1 pyramidal cells by using in vivo whole-cell recording in freely moving rats. We observed a high incidence of spikelets that occurred either in isolation or in bursts and could drive spiking as fast prepotentials of action potentials. Spikelets strongly contributed to spiking activity, driving approximately 30% of all action potentials. CA1 pyramidal cell firing and spikelet activity were comodulated as a function of the animal's location in the environment. We conclude that spikelets have a major impact on hippocampal activity during spatial exploration.
authors.affiliation: Bernstein Center for Computational Neuroscience, Humboldt University, 10115 Berlin, Germany. epsztein@inmed.univ-mrs.fr
authors.forename: Jérôme
authors.initials: J
authors.lastname: Epsztein
authors.forename: Albert K
authors.initials: AK
authors.lastname: Lee
authors.forename: Edith
authors.initials: E
authors.lastname: Chorev
authors.forename: Michael
authors.initials: M
authors.lastname: Brecht
mesh_terms: D000200:Action Potentials; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D005106:Exploratory Behavior; D008297:Male; D018782:Maze Learning; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013028:Space Perception