Abstract

Please join us for our fortnightly journal club will be online via zoom where two presenters will jointly present a topic together.

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The next topic is ‘variability of place and grid cell activities during spatial navigation’. In the first part, we will review how average firing rates of the place (and grid cell) activities depend on changes in the sensory input on a slow time scale (minutes to days). We will focus on a series of papers that modelled experiments where the size of the room or track is changed, including the following papers:

• O’Keefe & Burgess 1996 Nature, Geometric determinants of the place fields of hippocampal neurons, https://www.nature.com/articles/381425a0

• Laptev & Burgess 2019 Front Neural Circuits, Neural Dynamics Indicate Parallel Integration of Environmental and Self-Motion Information by Place and Grid Cells, https://www.frontiersin.org/articles/10.3389/fncir.2019.00059/full

In the second part, we will go beyond the average firing rate picture of place and grid cells. Starting with a brief overview of basic phenomena in place cells, the variability of place cell discharge will be discussed. An overview of the classical 1998 Fenton and Muller paper ‘Place cell discharge is extremely variable during individual passes of the rat through the firing field’ will introduce the concept of excess variability in place cell firing. More recent related work relates this excess variability to attentional states of the animal through experiments and a similar observation holds for grid cell discharge in the entorhinal cortex (see papers below).

• Place cell discharge is extremely variable during individual passes of the rat through the firing field, https://www.pnas.org/content/95/6/3182.short

• Attention-Like Modulation of Hippocampus Place Cell Discharge, https://www.jneurosci.org/content/30/13/4613.short

• Untethered firing fields and intermittent silences: Why grid‐cell discharge is so variable, https://onlinelibrary.wiley.com/doi/full/10.1002/hipo.23191