Hippocampal Global Remapping Can Occur without Input from the Medial Entorhinal Cortex

Abstract

SUMMARY The high storage capacity of the episodic memory system relies on distinct representations for events that are separated in time and space. The spatial component of these computations includes the formation of independent maps by hippocampal place cells across environments, referred to as global re-mapping. Such remapping is thought to emerge by the switching of input patterns from specialized spatially selective cells in medial entorhinal cortex (mEC), such as grid and border cells. Although it has been shown that acute manipulations of mEC firing patterns are sufficient for inducing hippocampal remapping, it remains unknown whether specialized spatial mEC inputs are necessary for the reorganization of hippocampal spatial representations. Here, we examined remapping in rats without mEC input to the hippocampus and found that highly distinct spatial maps emerged rapidly in every individual rat. Our data suggest that hippocampal spatial computations do not depend on inputs from specialized cell types in mEC.

Altered hippocampal place cell representation and theta rhythmicity following moderate prenatal alcohol exposure

“…Previous studies have also reported that moderate PAE can reduce mGluR5 receptor function in DG (Galindo et al, 2004) and lead to elevated histamine H3 receptor-mediated inhibition of glutamate release from perforant path nerve terminals (Varaschin et al, 2018). Likewise, the integrity of input from the entorhinal cortex, which forms the most prominent source of perforant path axons, is critical for place cell activity (Latuske et al, 2018), and damage to entorhinal cortical cells can produce a similar loss of place field stability and reduction in spatial tuning (Hales et al, 2014;Schlesiger et al, 2018;Van Cauter et al, 2008).…”

Hippocampal spike‐time correlations and place field overlaps during open field foraging

“…We examined several published datasets of extracellular recordings in hippocampal areas CA1 and CA3 during open field exploratory foraging. The following datasets were included in the analysis: two CA1 sessions from a teleportation experiment reported in Jezek, Henriksen, Treves, Moser, and Moser (), five CA1 sessions recorded in the Buzsaki lab (Mizuseki et al, 2013; Mizuseki et al, ; Mizuseki, Sirota, Pastalkova, & Buzsaki, ) (specifically session ec14.215, ec14.277, ec14.333, ec14.260, and ec15.047 from the openly available hc‐3 dataset), 16 CA1 sessions from wild‐type mice, and 16 CA1 sessions from Fmr1‐null mice recorded from Sparks, Talbot, Dvorak, and Fenton (), Talbot et al (), and Dvorak, Radwan, Sparks, Talbot, and Fenton (), also taken from the openly available hc‐16 dataset, 28 CA1 sessions in three rats from a remapping experiment reported in Schlesiger et al () and Schlesiger et al () and, finally, 178 CA3 sessions from seven rats in 11 rooms reported in Alme et al (). Details about the recordings and the experimental settings can be found in the respective references.…”

“…The distance d between two place fields was computed using the 2D Kolmogorov-Smirnov probability distance directly from the distributions of spike locations (Peacock, 1983 Talbot, and Fenton (2018), also taken from the openly available hc-16 dataset, 28 CA1 sessions in three rats from a remapping experiment reported in Schlesiger et al (2015) and Schlesiger et al (2018) and, finally, 178 CA3 sessions from seven rats in 11 rooms reported in Alme et al (2014). Details about the recordings and the experimental settings can be found in the respective references.…”

Hippocampal spike-time correlations and place-field overlaps during open field foraging

“…The following datasets were included in the analysis: 2 CA1 sessions from a teleportation experiment reported in (Jezek et al, 2011), 5 CA1 sessions recorded in the Buzsáki lab (K. Mizuseki et al, n.d.;Kenji Mizuseki, Diba, et al, 2014;Kenji Mizuseki, Sirota, et al, 2009) (specifically session ec14. 215, ec14.277, ec14.333, ec14.260, and ec15.047 from the openly available hc-3 dataset), 16 CA1 sessions from wild-type mice and 16 CA1 sessions from Fmr1-null mice recorded from (Sparks et al, 2017;Talbot et al, 2018;Dvorak et al, 2018), also taken from the openly available hc-16 dataset, 28 CA1 sessions in 3 rats from a remapping experiment reported in (Schlesiger, Cannova, et al, 2015;Schlesiger, Boublil, et al, 2018) and, finally, 178 CA3 sessions from 7 rats in 11 rooms reported in (Alme et al, 2014). Details about the recordings and the experimental settings can be found in the respective references.…”