title: Recent memory for socially transmitted food preferences in rats does not depend on the hippocampus.
abstract: The standard model of systems consolidation holds that the hippocampus (HPC) is involved only in the initial storage and retrieval of a memory. With time hippocampal-neocortical interactions slowly strengthen the neocortical memory, ultimately enabling retrieval of the memory without the HPC. Key support for this idea comes from experiments measuring memory recall in the socially-transmitted food preference (STFP) task in rats. HPC damage within a day or two of STFP learning can abolish recall, but similar damage five or more days after learning has no effect. We hypothesize that disruption of cellular consolidation outside the HPC could contribute to the amnesia with recent memories, perhaps playing a more important role than the loss of HPC. This view predicts that intraHPC infusion of Tetrodotoxin (TTX), which can block conduction of action potentials from the lesion sites, will block the retrograde amnesia in the STFP task. Here we confirm the previously reported retrograde amnesia with neurotoxic HPC damage within the first day after learning, but show that co-administration of TTX with the neurotoxin blocks the retrograde amnesia despite very extensive HPC damage. These results indicate that HPC damage disrupts cellular consolidation of the recent memory elsewhere; STFP memory may not ever depend on the HPC.
authors.affiliation: Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada. Electronic address: rajat.thapa@uleth.ca.
authors.forename: Rajat
authors.initials: R
authors.lastname: Thapa
authors.affiliation: Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada. Electronic address: fs1111@nyu.edu.
authors.forename: Fraser T
authors.initials: FT
authors.lastname: Sparks
authors.affiliation: Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada. Electronic address: whanif@ualberta.ca.
authors.forename: Wahab
authors.initials: W
authors.lastname: Hanif
authors.affiliation: Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada. Electronic address: tine.gulbrandsen@uleth.ca.
authors.forename: Tine
authors.initials: T
authors.lastname: Gulbrandsen
authors.affiliation: Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada. Electronic address: robert.sutherland@uleth.ca.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sutherland
mesh_terms: D000819:Animal Communication; D000818:Animals; D005518:Food Preferences / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007858:Learning / Q000187:drug effects / Q000502:physiology; D008297:Male; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D012919:Social Behavior; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D026941:Sodium Channel Blockers; D013779:Tetrodotoxin
keywords: Hippocampus; Rat; Retrograde amnesia; Socially transmitted food preference; Systems consolidation