Abstract

Neurons in the medial entorhinal cortex fire action potentials at regular spatial intervals, creating a striking grid-like pattern of spike rates spanning the whole environment of a navigating animal. This remarkable spatial code may represent a neural map for path integration. Recent advances using patch-clamp recordings from entorhinal cortex neurons in vitro and in vivo have revealed how the microcircuitry in the medial entorhinal cortex may contribute to grid cell firing patterns, and how grid cells may transform synaptic inputs into spike output during firing field crossings. These new findings provide key insights into the ingredients necessary to build a grid cell.

Highlights

  • An accurate representation of space is critical for an animal’s survival

  • Grid cell firing can be produced by a wide range of plausible mechanisms that can be captured by computational models

  • We have focused on the cellular, synaptic and network ingredients used to generate grid cell firing in the mammalian entorhinal cortex

Read more

Summary

Introduction

An accurate representation of space is critical for an animal’s survival. How does the brain accomplish this task at the level of single neurons and neuronal circuits? The mammalian hippocampus and entorhinal cortex contain neurons exhibiting spatially selective action potential firing: place cells, which are mainly found in hippocampal areas CA1 and CA3, typically fire at a single spatial location in an environment [1]. Various models have been proposed to explain how the striking grid cell firing pattern arises from network connectivity, synaptic mechanisms and intrinsic membrane properties These models have been broadly classified into oscillatory models and network models in the past; a more detailed and accurate classification has recently been proposed that dissects models according to how positional information is encoded, updated and read out [13]. In vitro experiments have provided new data about the connectivity of the MEC circuit [24,25] and in vivo whole-cell recordings in navigating animals [4,26] have offered the first glimpse into the transformations of synaptic input to spike output that give rise to grid cell firing Together, these studies have yielded crucial information about the cellular, synaptic and circuit ‘toolkit’ that the medial entorhinal cortex uses to build grid cells

Intrinsic membrane properties
Network connectivity
Synaptic inputs
Findings
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.