title: Separate elements of episodic memory subserved by distinct hippocampal-prefrontal connections.
abstract: Episodic memory formation depends on information about a stimulus being integrated within a precise spatial and temporal context, a process dependent on the hippocampus and prefrontal cortex. Investigations of putative functional interactions between these regions are complicated by multiple direct and indirect hippocampal-prefrontal connections. Here application of a pharmacogenetic deactivation technique enabled us to investigate the mnemonic contributions of two direct hippocampal-medial prefrontal cortex (mPFC) pathways, one arising in the dorsal CA1 (dCA1) and the other in the intermediate CA1 (iCA1). While deactivation of either pathway impaired episodic memory, the resulting pattern of mnemonic deficits was different: deactivation of the dCA1→mPFC pathway selectively disrupted temporal order judgments while iCA1→mPFC pathway deactivation disrupted spatial memory. These findings reveal a previously unsuspected division of function among CA1 neurons that project directly to the mPFC. Such subnetworks may enable the distinctiveness of contextual information to be maintained in an episodic memory circuit.
authors.affiliation: School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
authors.forename: Gareth R I
authors.initials: GR
authors.lastname: Barker
authors.affiliation: School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Banks
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, UK.
authors.forename: Hannah
authors.identifier: 0000-0002-2497-549X
authors.initials: H
authors.lastname: Scott
authors.affiliation: Oxford BioMedica (UK) Ltd Medawar Centre, Oxford, UK.
authors.forename: G Scott
authors.initials: GS
authors.lastname: Ralph
authors.affiliation: Oxford BioMedica (UK) Ltd Medawar Centre, Oxford, UK.
authors.forename: Kyriacos A
authors.initials: KA
authors.lastname: Mitrophanous
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, UK.
authors.forename: Liang-Fong
authors.initials: LF
authors.lastname: Wong
authors.affiliation: School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
authors.forename: Zafar I
authors.initials: ZI
authors.lastname: Bashir
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, UK.
authors.forename: James B
authors.initials: JB
authors.lastname: Uney
authors.affiliation: School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
authors.forename: E Clea
authors.initials: EC
authors.lastname: Warburton
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D061212:Memory, Episodic; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D051381:Rats; D065852:Spatial Memory / Q000502:physiology