Endopiriform neurons projecting to ventral CA1 are a critical node for recognition memory
- Department of Biomedicine, Aarhus University, Denmark
- PROMEMO, The Center for Proteins in Memory, Aarhus University, Denmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus University, Denmark
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, United States
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, United States
Figures
Figure 1 with 1 supplement
Endopiriform projects to the ventral CA1.
(A) Schematic diagram of a retrograde tracer injection performed. CAV-2-Cre or CTB647 was used in combination with Ai14 or wild-type mice, respectively. (B) An example fluorescent image of the …
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Figure 1—source data 1
Presynaptic cell numbers projecting to vCA1.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig1-data1-v1.xlsx
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Figure 1—source data 2
Presynaptic cell numbers projecting to vCA1.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig1-data2-v1.xlsx
Figure 1—figure supplement 1
Whole brain distribution of ventral CA1 (vCA1)-projecting neurons.
(A) Fluorescent images of the injection site (vCA1) of CAV2-Cre (60 nl) of Ai14 mice for analysis of presynaptic neuron distribution using AMaSiNe. The presynaptic cell numbers counted in individual …
Figure 2 with 1 supplement
Axon branching of ventral CA1 (vCA1)-projecting endopiriform (EN) neurons.
(A) Schematic diagram of injection performed and two hypothesized outcomes. Yellow color indicates double-labeled neurons. PFC: Prefrontal cortex, ACC: Anterior cingulate cortex, MC: Motor cortex, …
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Figure 2—source data 1
Single and double labeled EN cell numbers.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig2-data1-v1.xlsx
Figure 2—figure supplement 1
Axon branching of ventral CA1 (vCA1)-projecting endopiriform (EN) neurons.
(A-D) Example fluorescent images of branching of vCA1-projecting neurons. All images were from the same mouse shown in Figure 2N–O. DG: Dentate gyrus.
Figure 3 with 1 supplement
EN projection pattern in ventral CA1 (vCA1).
(A) Schematic diagram of injection performed. (B) An example fluorescent image of a horizontal brain section containing an injection site in endopiriform (EN). (C) An example fluorescent image of …
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Figure 3—source data 1
Normalized GFP signals in hippocampal slices.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig3-data1-v1.xlsx
Figure 3—figure supplement 1
Projections of ENvCA-proj. neurons to the hippocampus.
(A) Top: An example fluorescent image of intermediate hippocampal sections from the same brain as in Figure 3B and C. Bottom: GFP signal profile at the distal and proximal region indicated in the …
Figure 4 with 1 supplement
ENvCA1-proj. neurons target ventral CA1 (vCA1) interneurons.
(A) Schematic diagram of injection performed for monosynaptic rabies tracing. Flox-TVA-GFP (60 nl) was injected into the vCA1. 4 wk later, Rabies-mCherry (60 nl) was injected. (B) Location of …
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Figure 4—source data 1
Number of presynaptic cells projecting to ventral hippocampal interneurons.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig4-data1-v1.xlsx
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Figure 4—source data 2
Recorded EN-evoked EPSPs from ventral CA1 interneurons.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig4-data2-v1.xlsx
Figure 4—figure supplement 1
Presynaptic neurons of ventral hippocampal GABAergic neurons.
(A) Example fluorescent images of starter cells in ventral CA1 (vCA1). TVA_oG-expressing neurons were labeled by GFP and rabies-expressing neurons were labeled by mCherry. GFP and mCherry …
Figure 5 with 1 supplement
EN disynaptically inhibits ventral CA1 (vCA1) pyramidal neurons.
(A) A confocal image of recorded pyramidal neurons in vCA1. Recorded pyramidal neurons were filled with biocytin and post-labeled with Alexa488. Ori.: oriens, Super.: superficial layer pyramidal …
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Figure 5—source data 1
All EPSC and IPSC amplitude in Figure 5C.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig5-data1-v1.xlsx
Figure 5—figure supplement 1
Endopiriform (EN)-mediated excitatory inputs to ventral hippocampal neurons.
(A) Plots comparing peak amplitude of photo-evoked excitatory postsynaptic currents (EPSCs) in superficial and deep pyramidal neurons. Thin gray lines indicate paired data. Median peak amplitude; …
Figure 6 with 1 supplement
ENvCA1-proj. neurons receive inputs from the piriform cortex and within endopiriform (EN).
(A) Schematic diagram of performed. After CAV2-Cre (60 nl) injection into the ventral CA1 (vCA1), flox-TVA-mCherry (100 nl) was injected into the EN. 4 wk later, Rabies-GFP (100 nl) was injected …
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Figure 6—source data 1
Numbers of presynaptic cells projecting to ENvCA1-proj. neurons.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig6-data1-v1.xlsx
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Figure 6—source data 2
Number of presynaptic piriform cells projecting to ENvCA1-proj. neurons in different layers.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig6-data2-v1.xlsx
Figure 6—figure supplement 1
Presynaptic neurons of ENvCA1-proj. Neurons.
(A) An example fluorescent image of starter cells in endopiriform (EN). (B–D) Expanded images of the area marked by a white square in panel A. White allows indicate starter cells. (E) Example …
Figure 7 with 2 supplements
Activity of ENvCA1-proj. neurons correlate with social/object discrimination performance.
(A) Right and Middle: Schematic diagrams of injection and optic cannula implantation performed. CAV2-Cre (60 nl) was injected into the vCA1, and dlox-jGCaMP8s (100 nl) was injected into the …
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Figure 7—source data 1
Raw data of Figure 7E, G.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig7-data1-v1.xlsx
Figure 7—figure supplement 1
Nose point location and calcium signal data during social memory test.
Maps of nose points (filled gray circles) and calcium events (filled red circles) in the arena. Heat maps of the same data (but cumulative time and calcium event are separated) were also shown for …
Figure 7—figure supplement 2
Calcium signals during exploratory behavior in an open field, pretest, and familiarization test.
(A) Example of maps of nose points and calcium events in open field arena. All p-values in a correlation map were presented in Supplementary file 2. (B) Correlation plots of event number and …
Figure 8 with 2 supplements
Chemogenetic inhibition of ENvCA1-proj. neurons specifically impairs recognition memory.
(A) Schematic diagram of injection performed. (B) Left: An example fluorescent image showing expression of hM4Di in ENCA1-proj. neurons. Right: Expansion of areas marked by white rectangle in the …
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Figure 8—source data 1
Time in each chambers/ interaction zones during sociablity test.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig8-data1-v1.xlsx
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Figure 8—source data 2
Time in chambers/interaction zones during discrimination test.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig8-data2-v1.xlsx
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Figure 8—source data 3
Interaction time with objects during novel object recognition test.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig8-data3-v1.xlsx
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Figure 8—source data 4
% of freezing during each test phases of trace fear conditioning test.
- https://cdn.elifesciences.org/articles/99642/elife-99642-fig8-data4-v1.xlsx
Figure 8—figure supplement 1
The effect of chemoegentic inhibition of ENvCA1-proj. neurons on the pretest and locomotion.
(A) Frequency-current (FI) curve showing the effect of clozapine-N-oxide (CNO) on action potential number generated by current injection. Recording was made from hM4Di expressing ENvCA1-proj. …
Figure 8—figure supplement 2
The effect of chemoegentic inhibition of ENvCA1-proj. neurons on trace fear conditioning. (A) Schematic of trace fear conditioning protocol. (B) The effect of clozapine-N-oxide (CNO) on freezing behavior during conditioning. Black indicates saline treated group and red indicates CNO treated group. Data points of individual mice are indicated by empty circles. Thick horizontal bars indicate median values. Saline vs CNO, F(1, 9)=2.52, p=0.115; two-way ANOVA. (C) The effect of CNO on freezing behavior during recall to context ‘A.’ Median values of freezing %: Saline = 14.91, CNO = 30.13. Saline vs CNO, p=0.576; one-way ANOVA. (D) The effect of CNO on freezing behavior during conditional stimulus recall in context ‘B.’ Saline vs CNO, F (1, 9)=0.38, p=0.54; two-way ANOVA.
Figure 9
The role of ENvCA1-proj.neurons in recognition memory.
(A) Summary of findings from in vivo experiments. (B) The model of ENvCA1-proj. circuit function in recognition memory. During memory-guided exploration, recurrent circuits in ENvCA1-proj. neurons …
Tables
Table 1
Presynaptic cell numbers projecting to vCA1 in different brain areas.
| Brain areas | Brain #1 | Brain #2 | Brain #3 | Brain #4 | Brain #5 |
|---|---|---|---|---|---|
| EN | 288 | 201 | 310 | 210 | 250 |
| BLA | 85 | 107 | 175 | 208 | 118 |
| SP (lateral) | 27 | 36 | 69 | 69 | 17 |
| SP (medial) | 69 | 111 | 130 | 127 | 121 |
| Sum | 469 | 455 | 684 | 614 | 506 |
Table 2
ANOVA comparison of Figure 6D.
| Compared brain areas | p-value | |
|---|---|---|
| Agranular insular | AOB | 0.764 |
| Agranular insular | PIR | 0.617 |
| Agranular insular | ENT | 0.624 |
| Agranular insular | CLA | 0.921 |
| Agranular insular | EN | 0.971 |
| Agranular insular | Palidum | 0.588 |
| Agranular insular | Substantia innominata | 0.44 |
| AOB | PIR | 0.016 |
| AOB | ENT | 1 |
| AOB | CLA | 1 |
| AOB | EN | 0.156 |
| AOB | Palidum | 1 |
| AOB | Substantia innominata | 1 |
| PIR | ENT | 0.008 |
| PIR | CLA | 0.048 |
| PIR | EN | 0.994 |
| PIR | Palidum | 0.006 |
| PIR | Substantia innominata | 0.003 |
| ENT | CLA | 1 |
| ENT | EN | 0.091 |
| ENT | Palidum | 1 |
| ENT | Substantia innominata | 1 |
| CLA | EN | 0.317 |
| CLA | Palidum | 0.999 |
| CLA | Substantia innominata | 0.992 |
| EN | Palidum | 0.079 |
| EN | Substantia innominata | 0.043 |
| Palidum | Substantia innominata | 1 |
Additional files
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Supplementary file 1
p-values of correlation plots in Figure 7—figure supplement 1.
- https://cdn.elifesciences.org/articles/99642/elife-99642-supp1-v1.xlsx
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Supplementary file 2
p-values of correlation plots in Figure 7—figure supplement 2A.
- https://cdn.elifesciences.org/articles/99642/elife-99642-supp2-v1.xlsx
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MDAR checklist
- https://cdn.elifesciences.org/articles/99642/elife-99642-mdarchecklist1-v1.docx
