Excitatory Microcircuits within Superficial Layers of the Medial Entorhinal Cortex

Publication date: 9 May 2017
Source:Cell Reports, Volume 19, Issue 6
Author(s): Jochen Winterer, Nikolaus Maier, Christian Wozny, Prateep Beed, Jörg Breustedt, Roberta Evangelista, Yangfan Peng, Tiziano D'Albis, Richard Kempter, Dietmar Schmitz
The distinctive firing pattern of grid cells in the medial entorhinal cortex (MEC) supports its role in the representation of space. It is widely believed that the hexagonal firing field of grid cells emerges from neural dynamics that depend on the local microcircuitry. However, local networks within the MEC are still not sufficiently characterized. Here, applying up to eight simultaneous whole-cell recordings in acute brain slices, we demonstrate the existence of unitary excitatory connections between principal neurons in the superficial layers of the MEC. In particular, we find prevalent feed-forward excitation from pyramidal neurons in layer III and layer II onto stellate cells in layer II, which might contribute to the generation or the inheritance of grid cell patterns.

Graphical abstract

Teaser

Winterer et al. record from up to eight principal cells simultaneously in slices of the medial entorhinal cortex, a brain area that robustly expresses grid cells. The authors demonstrate a cell type-specific and unidirectional connectivity scheme, providing insight into the organizational principles of grid cell generation.


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