Grid cells require excitatory drive from the hippocampus

Abstract

To determine how hippocampal backprojections influence spatially periodic firing in grid cells, we recorded neural activity in the medial entorhinal cortex (MEC) of rats after temporary inactivation of the hippocampus. We report two major changes in entorhinal grid cells. First, hippocampal inactivation gradually and selectively extinguished the grid pattern. Second, the same grid cells that lost their grid fields acquired substantial tuning to the direction of the rat's head. This transition in firing properties was contingent on a drop in the average firing rate of the grid cells and could be replicated by the removal of an external excitatory drive in an attractor network model in which grid structure emerges by velocity-dependent translation of activity across a network with inhibitory connections. These results point to excitatory drive from the hippocampus, and possibly other regions, as one prerequisite for the formation and translocation of grid patterns in the MEC.

Locating and navigation mechanism based on place-cell and grid-cell models

“…It is commonly believed that place cells may be driven by grid cells (McNaughton et al 2006;Solstad et al 2006a, b;Molter and Yamaguchi 2008;Si and Treves 2009 Sreenivasan and Fiete 2011). In the study by Bonnevie et al (2013), experimental data suggest that the feedback from place cells to grid cells is more prominent than that of grid cells on place cells. Meanwhile, the study addresses that grid cells may also play an important role on navigation.…”

“…Place cells in the model mainly undertake the function of locating, while grid cells are concerned more on the integration of the navigation path. Especially, it is known from the literature (McNaughton et al 2006;Molter and Yamaguchi 2008;O'Keefe and Burgess 2005;Bonnevie et al 2013) that the connection is mutual between hippocampus place cells and cortex grid cells. Therefore, we design an interactive mechanism of these two kinds of neurons.…”

How Animals Find Their Way in Space. Experiments and Modeling

“…Кроме того, показано, что в онтогенезе клетки решетки развиваются последними, в частности, у крыс на 17-20 день постнатального развития, когда все остальные нейронные системы, связанные с навигацией (клетки поворота головы, клетки границ и клетки места), уже сформированы [55]. Наконец известно, что при блокаде активности в гиппокампе клетки решетки теряют свою активность [56].…”

Le codage de l’espace

“…Au même âge, en revanche, les cellules de grille expriment une très faible périodicité spatiale, ce qui suggère, avec d'autres expériences, que le signal des cellules de grilles n'est pas nécessaire à l'activité spatiale hippocampique [25]. Des travaux des Moser suggèrent même une dépendance inverse : l'inactivation de l'hippocampe fait perdre la périodicité de leur activité aux cellules de grille et les transforme en cellules de direction de la tête [26]. Ainsi, le codage de l'espace n'est pas un processus hiérarchique aboutissant à l'hippocampe, mais repose sur des relations réciproques entre l'hippocampe et le cortex entorhinal.…”