SCIENCEsciencemag.org 9JULY2021•VOL 373 ISSUE 6551 243
Fig. 1. CA1 neurons in flying bats encode nonlocal positions, primarily in
the future.(A) Illustration of nonlocal coding hypothesis. Top: A subset of
classical place cells (light purple circles) with place fields overlapping with the
immediate spatial position (local). Bottom: Neurons with nonlocal fields encoding
past (blue) and future (red) spatial positions. (B) Example of a single flight
(left) and the spatial coverage (gray lines) shown from the top and the side for
an entire recording session. Black trace corresponds to the example flight
trajectory. (C) 3D color-coded firing rate maps for three examples of 3D place
cells. Bias-corrected spatial information values for the three cells is as follows:
top, 0.81 bits; middle, 0.61 bits; and bottom, 0.61 bits. The peak firing rate
is indicated. (D) Same as (C) but for three example neurons exhibiting higher 3D
spatial information for future positions. Spatial information values for the
example neurons are as follows: top, lag zero = 0.10 bits [not significant (n.s.)]
and optimal lag = 0.28 bits; middle: lag zero = 0.11 bits (n.s) and optimal
lag = 0.30 bits; and bottom, lag zero = 0.18 bits (n.s.) and optimal lag = 0.58 bits.
(E) Normalized spatial information across time lags for each neuron with
significant spatial information at one or more time lags (–1000 to 1000 ms in
100-ms steps). Rank order is based on the time lag with maximal spatial
information. (F) Cumulative sum of the time lags with maximal spatial information
for each neuron (top) and summary of the bias-corrected spatial information
values at each lag (one value per neuron) (bottom). The 25th (bottom gray line),
50th (middle black line), and 75th (top gray line) percentiles are shown.
(G) Left: Convex hull representation of all significant spatiotemporal field
locations across all recorded neurons. Right: top-down view showing location of
spatiotemporal field centers. Color code indicates the time lag of maximal
spatial information. (H) Field volume across lags (left) and Euclidean distance
between all field centers at each lag (right). The 25th (bottom gray line),
50th (middle black line), and 75th (top gray line) percentiles are shown.RESEARCH | REPORTS