GPS in the hippocampus

Supplementary video from the paper "Hippocampal place-cell sequences depict future paths to remembered goals," by Brad E. Pfeiffer and David J. Foster, published in Nature (2013) doi: http://dx.doi.org/10.1038/nature12112 http://www.nature.com/nature/journal/... "Representative trajectory events demonstrating how the events progress across the arena through time. This video depicts three general 'types' of trajectory events: home-events (events which occur while the rat is at the HOME well), away-events (events which occur while the rat is away from the HOME well) that demonstrate a trajectory that ends at HOME, and away-events that demonstrate a trajectory that does not end at or cross HOME. Note the wide variety of paths encoded by the trajectory events and the smoothness of the trajectory. Each frame depicts the predicted position of the rat (posterior probability) within the 2 m x 2 m arena given the unit firing patterns that occurred during that frame. The posterior probabilities are shown as a colourmap, which ranges from black (0) to white (0.1). Each frame spans 20 ms, and is advanced from the previous by 5 ms. The time from the start of each event is depicted at the bottom of the video. The rat's physical position and head direction throughout each event are depicted by the cartoon white rat, and the locations of the 36 wells in the floor of the arena are shown as white squares. The HOME well location is coloured in cyan. If a RANDOM well is active (filled with chocolate) or if the rat is currently at the RANDOM well consuming the reward, it is coloured in green. If the HOME well is active or if the rat is currently at the HOME well consuming the reward, the previously active RANDOM well is coloured in red. The cyan line connects the peak posterior probabilities for each frame. At the end of each trajectory sequence, the entire event is shown collapsed across time."