title: Theta sequences are essential for internally generated hippocampal firing fields.
abstract: Sensory cue inputs and memory-related internal brain activities govern the firing of hippocampal neurons, but which specific firing patterns are induced by either of the two processes remains unclear. We found that sensory cues guided the firing of neurons in rats on a timescale of seconds and supported the formation of spatial firing fields. Independently of the sensory inputs, the memory-related network activity coordinated the firing of neurons not only on a second-long timescale, but also on a millisecond-long timescale, and was dependent on medial septum inputs. We propose a network mechanism that might coordinate this internally generated firing. Overall, we suggest that two independent mechanisms support the formation of spatial firing fields in hippocampus, but only the internally organized system supports short-timescale sequential firing and episodic memory.
authors.affiliation: Janelia Research Campus, Ashburn, Virginia, USA.
authors.forename: Yingxue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: 1] Janelia Research Campus, Ashburn, Virginia, USA. [2] Center for Theoretical Neuroscience, Columbia University, New York, New York, USA.
authors.forename: Sandro
authors.initials: S
authors.lastname: Romani
authors.affiliation: 1] Janelia Research Campus, Ashburn, Virginia, USA. [2] University of Chicago, Neuroscience Graduate Program, Chicago, Illinois, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Lustig
authors.affiliation: Janelia Research Campus, Ashburn, Virginia, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Leonardo
authors.affiliation: Janelia Research Campus, Ashburn, Virginia, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Pastalkova
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D003463:Cues; D058785:GABA-A Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008297:Male; D061212:Memory, Episodic; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010507:Periodicity; D020318:Rats, Long-Evans; D013826:Theta Rhythm / Q000187:drug effects / Q000502:physiology*
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol