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Sequence progression across time-encoding MEC cells correlates with animal wait time
a, Velocity leading into (time < 0 s), during (0 s < time < 6 s) and after 6-s Door Stop wait interval for all short wait (pink) and long wait (green) correct trials (dark line, mean; shading, s.e.m.). b, Examples of normalized ΔF/F sequence for (top) all time-encoding cells from an individual trial (same cell-ordering and same session in left and right; short wait = 6.1 s, long wait = 8.0 s), (middle) across all trials from an individual FOV (same cell-ordering and same session in left and right; mean short wait = 6.3 ± 0.3 s (mean ± s.d.), mean long wait = 8.3 ± 0.7 s (mean ± s.d.)) and (bottom) for all time-encoding cells across all FOVs (same cell ordering, includes multiple sessions in left and right; mean short wait = 6.5 ± 0.3 (mean ± s.d.), mean long wait = 8.0 ± 0.7 (mean ± s.d.)), short waits (6–7 s; left) and long waits (7–9.5 s; right). Cells were ordered according to each cell’s mean center of mass across all short wait trials (earliest mean center of mass at top, latest at bottom). Pink and green lines are linear fits of short (pink, left) and long (green, right) wait sequences. c, Plot of slopes (from linear fits of cell activations per second) as a function of animal wait time for all individual trials (each circle represents a single trial, as in top panel of b). Cells were ordered according to each cell’s mean center of mass across all correct (6–9.5 s) trials (earliest mean center of mass at top, latest at bottom; n = 73 wait trials from 4 imaging fields in 3 mice).

Sequence progression across time-encoding MEC cells correlates with animal wait time a, Velocity leading into (time < 0 s), during (0 s < time < 6 s) and after 6-s Door Stop wait interval for all short wait (pink) and long wait (green) correct trials (dark line, mean; shading, s.e.m.). b, Examples of normalized ΔF/F sequence for (top) all time-encoding cells from an individual trial (same cell-ordering and same session in left and right; short wait = 6.1 s, long wait = 8.0 s), (middle) across all trials from an individual FOV (same cell-ordering and same session in left and right; mean short wait = 6.3 ± 0.3 s (mean ± s.d.), mean long wait = 8.3 ± 0.7 s (mean ± s.d.)) and (bottom) for all time-encoding cells across all FOVs (same cell ordering, includes multiple sessions in left and right; mean short wait = 6.5 ± 0.3 (mean ± s.d.), mean long wait = 8.0 ± 0.7 (mean ± s.d.)), short waits (6–7 s; left) and long waits (7–9.5 s; right). Cells were ordered according to each cell’s mean center of mass across all short wait trials (earliest mean center of mass at top, latest at bottom). Pink and green lines are linear fits of short (pink, left) and long (green, right) wait sequences. c, Plot of slopes (from linear fits of cell activations per second) as a function of animal wait time for all individual trials (each circle represents a single trial, as in top panel of b). Cells were ordered according to each cell’s mean center of mass across all correct (6–9.5 s) trials (earliest mean center of mass at top, latest at bottom; n = 73 wait trials from 4 imaging fields in 3 mice).

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The medial entorhinal cortex (MEC) is known to contain spatial encoding neurons that likely contribute to encoding spatial aspects of episodic memories. However, little is known about the role MEC plays in encoding temporal aspects of episodic memories, particularly during immobility. Here using a virtual ‘Door Stop’ task for mice, we show that MEC...

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