Fig. 6: MEC L5a routes visual information to the hippocampus and superficial MEC through the DV pathway.
From: A non-canonical visual cortical-entorhinal pathway contributes to spatial navigation
a Schematic illustrating experimental strategy. b1–3 Confocal images showing the expression of retrograde AAV (red) injected at MEC L2/3 and trans-multisynaptic anterograde HSV (green) at 60 (b1) or 72 HPI (b2). Distribution of L5a neurons co-expressing AAV and HSV along the DV axis at 60 and 72 HPI (b3; n = 6 slices from 3 mice/group). c1–3 Confocal images showing the expression of retrograde AAV (red) injected at iCA1 and trans-multisynaptic anterograde HSV (green) at 60 (c1) or 72 HPI (c2). Distribution of L5a neurons co-expressing AAV and HSV along the DV axis at 60 and 72 HPI (c3; n = 6 slices from 3 mice/group). d1–3 Confocal images showing the expression of retrograde AAV (red) injected at vCA1 and trans-multisynaptic anterograde HSV (green) at 60 (d1) or 72 HPI (d2). Distribution of L5a neurons co-expressing AAV and HSV along the DV axis at 60 and 72 HPI (d3; n = 6 slices from 3 mice/group). e Distribution of MEC L2/3-projecting, iCA1-projecting, vCA1-projecting and EGFP-positive L5a neurons along the DV axis at 60 HPI (n = 6 slices from 3 mice/group). f Comparison of L5b/6 EGFP-positive neuron numbers within MEC subdivisions (n = 9 mice; **P = 0.0039). g Schematic illustrating experimental strategy. h Representative traces exhibiting responses of vCE L5b SOM INs to optical stimulation by yellow and blue pulses. i Left: representative traces exhibiting effects of pharmacological blockers on EPSCs (top) and IPSCs (bottom) recorded from ME L5a PCs following activation of ChR2-mCherry expressing fibers from vCE L5a PCs. Right: representative traces exhibiting effects of inhibiting SOM INs with yellow light (1 s) on blue light-evoked IPSCs (5 Hz). j Comparison of IPSC amplitudes of ME L5a PCs with yellow light off and on (n = 12 cells from 3 mice; ***P = 0.0002). Scale bars, 100 μm (b1, b2 left, c1 left and d1 left), 50 μm (others). Two-sided Wilcoxon signed-rank test (f and j). Error bars represent SEM (b–e). Source data are provided as a Source Data file.
