Nature 495, 199–204 (2013); doi:10.1038/nature11973

In this Article, tetrode recordings from mice navigating in real environments and on virtual reality linear tracks were used to develop a classifier that was subsequently used to identify grid cells within our set of intracellular whole-cell recordings. Owing to an error in the way the analogue angular encoder signal detecting rotation of the treadmill was digitized and post-processed, the distances run by the mice along the one-dimensional virtual reality tracks during the tetrode recordings are approximately 5% to 30% longer than reported. (Track lengths for whole-cell recordings in virtual reality are unaffected.) Correct track lengths for tetrode recordings by date are provided in Table 1 of this Corrigendum. Track lengths affect the x axes in Fig. 2d–f, Supplementary Fig. 6b, and the one-dimensional virtual reality portion of Supplementary Fig. 9. Because the majority of one-dimensional virtual reality tracks were about 30% longer, we corrected the classifier to require three in-field to out-of-field switches per 5.2 m of linear track. As expected, the correct classifier makes the same decisions as the original for both whole-cell and tetrode recordings. The new track lengths lead to small changes in the mean field width (40 ± 11 cm), peak firing rate (12 ± 6 Hz) and number of fields per metre (0.7 ± 0.3) for tetrode virtual reality data in Supplementary Fig. 6d–f. In addition, two cells in Supplementary Fig. 9 part 5 should have been labelled ‘T10_20100805_t2_c6’ (third cell from top, left panel) and ‘T10_20100811_t2_c2’ (fourth cell from top, left panel), and the Supplementary Methods should state that when two clusters were identified as the same cell due to the use of both positive and negative thresholds, we kept only one of the clusters. These corrections have no impact on the results, conclusions and interpretation of this Article. The errors have been corrected in Fig. 2 of the HTML and PDF versions online and in Supplementary Figs 6 and 9 of the original Supplementary Information.

Table 1 Corrected track lengths
Full size table