Extended Data Fig. 7: Validation of injection site and goal-oriented learning in in vivo two-photon calcium imaging experiments.
From: Hippocampus shapes entorhinal cortical output through a direct feedback circuit
a. (a1) Confocal image of horizontal brain slice stained for RFP showing injection of AAV 2.5 Syn DIO hM4D mCherry in dorsal CA1 of a CamKII-Cre mouse. (a2) Confocal image of horizontal section from the same mouse as in a1 stained for RFP and DAPI showing the injection site (green neurons) for AAV 2.1 SynFlex GCaMP6s in ECL2/3, and red hippocampal axons in ECL2/3 and ECL5. (a3-a4) Same as a2 but only green (a3) and red (a4) channels. b-d. Same as (a) for different animals used in the two-photon calcium imaging experiments. e. (e1) Confocal image of horizontal brain slice for RFP showing injection of AAV 2.5 Syn DIO hM4D mCherry in dorsal CA1 of a wildtype mouse. (e2) Confocal image of horizontal section from the same mouse as in e1 stained for RFP and DAPI showing the injection site (green neurons) for AAV 2.1 SynFlex GCaMP6s and AAV 2.retro Syn Cre in ECL2/3. While we targeted ECL2/3 projecting hippocampal neurons, we see red hippocampal axons to ECL5 as well. All scale bars are 100 µm. White dotted lines demarcate the different sub-regions of the hippocampus (CA1 or Sub – subiculum) or the different EC layers. The confocal images show all the five animals used in the experiment.
