Fig. 2: Physical location of larval zebrafish can be decoded from the population activity of PCs.
From: A population code for spatial representation in the zebrafish telencephalon
a, Distribution of binarized telencephalic PFs in the chamber (median across animals). b, Median decoder error across animals at each bin within the chamber. To decode the physical location of the animal, a direct basis decoder was applied to telencephalic PCs (Methods). For all panels except f,g, the 1,000 cells with the highest spatial specificity were used as input to the decoder. c, Example traces show the x (top) and y (bottom) coordinates of the true (black) and decoded (red) animal locations. d, Activity of PCs across the final 3 min of c, together with true x (top) and y (bottom) coordinates of the animal (white overlay). Activity is shown two ways, sorting each cell by either the x or y component of its PF’s COM. e, Decoding performance for cells from different brain regions: PCs across the entire brain (PC), telencephalic PCs (Tel. PC), mes- and rhombencephalic PCs (M + R PC) and optic tectum cells (OT cells). Three controls are shown: random non-PCs (control 1, C1), uniformly random chamber positions (control 2, C2) and centroid of the animal’s spatial occupancy map (control 3, C3). Black horizontal bars represent median across animals. f, Decoder error as a function of the number of telencephalic cells included, in descending order of spatial tuning (Methods). Solid line indicates the mean and the shaded region indicates s.d. (the same applies to g). g, Decoder error as a function of the number of PCs included, using greedy selection to minimize redundancy (Methods). h, Distribution of decoder error across time (pooled across animals). Vertical solid line denotes median error, dashed line the behaviour-informed baseline and dotted line the accessible length of the chamber long axis. Scale bars, 10 mm.
