Let mice play video game, and the scientists study the hippocampal coding in the brain

Brain Windows blogged this paper.

These could be used to explain how place cells remap their selectivity when a mouse (or a human) moves into a new environment. This also could be used to do more in depth studies of the mental replay of place locations that has been previously recorded in the activity patterns of the hippocampus. The technique itself is about as sexy as neuroscience gets.

I feel it is a very interesting experiment, although I cannot understand the things discovered from this experiment. Also, this paper reminds me the lovely dog occurs in Wii Fit Plus video game, which will run around you when you are doing exercises …

Nature 461, 941-946 (15 October 2009)
DOI: 10.1038/nature08499; Received 8 July 2009; Accepted 15 September 2009

Intracellular dynamics of hippocampal place cells during virtual navigation

Christopher D. Harvey 1,2,3, Forrest Collman 1,2,3, Daniel A. Dombeck 1,2,3 & David W. Tank 1,2,3
1. Princeton Neuroscience Institute,
2. Lewis-Sigler Institute for Integrative Genomics,
3. Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA

Correspondence to: David W. Tank1,2,3 Correspondence and requests for materials should be addressed to D.W.T. (Email: dwtank@princeton.edu).

Hippocampal place cells encode spatial information in rate and temporal codes. To examine the mechanisms underlying hippocampal coding, here we measured the intracellular dynamics of place cells by combining in vivo whole-cell recordings with a virtual-reality system. Head-restrained mice, running on a spherical treadmill, interacted with a computer-generated visual environment to perform spatial behaviours. Robust place-cell activity was present during movement along a virtual linear track. From whole-cell recordings, we identified three subthreshold signatures of place fields: an asymmetric ramp-like depolarization of the baseline membrane potential, an increase in the amplitude of intracellular theta oscillations, and a phase precession of the intracellular theta oscillation relative to the extracellularly recorded theta rhythm. These intracellular dynamics underlie the primary features of place-cell rate and temporal codes. The virtual-reality system developed here will enable new experimental approaches to study the neural circuits underlying navigation.