Aberrant hippocampal Ca2+ microwaves following synapsin-dependent adeno-associated viral expression of Ca2+ indicators
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Germany
- University Hospital Bonn, Germany
- Department of Epileptology, University Hospital Bonn, Germany
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Germany
- NeuroTechnology Center, Columbia University, United States
- Brain Research Institute, University of Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Switzerland
- German Center for Neurodegenerative Diseases (DZNE), Germany
Figures
Figure 1
Development of Ca2+ microwaves travelling through hippocampus following GCaMP transduction.
(a) Experimental protocol to examine CA1 neuronal activity using two-photon imaging following adeno-associated viral (AAV) transduction of genetically encoded Ca2+ indicators. (b) …
Figure 2
Aberrant Ca2+ microwaves are consistent across laboratories and genetically encoded calcium indicator (GECI) variant.
(a) Boxplot (median ± quartiles and range) of the occurrence rate of aberrant Ca2+ microwaves in CA1 at the different institutes at 6–8 wk after injection of GCaMP6s or GCaMP6m (number of animals in …
Author response image 1
Plot of Ca2+ micro-wave frequency (left: number of Ca2+ waves/min) or occurrence (right: yes/no) against the animal age at the time of viral injection.
Blue line is linear (left) or logistic (right) fit to the data with 95% confidence level.
Videos
Video 1
GCaMP6s two-photon calcium imaging in the hippocampal CA1 region, around 100 µm beneath the hippocampal surface (stratum pyramidale), FOV ~600x600 µm, ~4 wk after transduction of AAV1 particles containing pAAV.Syn.GCaMP6s.WPRE.SV40 (Addgene plasmid #100843) in a mature bl6 wildtype mouse.
Imaging wavelength = 940 nm, acquisition speed = 15 frames/s. Movie played at ×5 acquisition speed. Imaging was performed at the IEECR/University of Bonn.
Video 2
GCaMP6s two-photon calcium imaging in the hippocampal CA1 region, around 100 µm beneath the hippocampal surface (stratum pyramidale), FOV ~450x450 µm, ~7 wk after transduction of AAV1 particles containing pAAV.Syn.GCaMP6s.WPRE.SV40 (Addgene plasmid #100843) in an ~3-month-old transgenic mouse (same as in Video 2; Scn2aA263V model of genetic epilepsy).
Imaging wave length = 940 nm, acquisition speed = 15 frames/s. Movie played at ×5 acquisition speed. Imaging was performed at the IEECR/University of Bonn.
Video 3
Same animal (Scn2aA263V model of genetic epilepsy) and time point of imaging as in Video 4.
GCaMP6s two-photon calcium imaging in the hippocampal CA1 region, around 25 µm beneath the hippocampal surface (stratum oriens), FOV ~350x350 µm, ~7 wk after transduction of AAV1 particles …
Video 4
GCaMP6s two-photon calcium imaging in the hippocampal CA1 region, around 100 µm beneath the hippocampal surface (stratum pyramidale), FOV ~450x450 µm, ~2 wk after transduction of AAV1 particles containing pAAV.Syn.GCaMP6s.WPRE.SV40 (Addgene plasmid #100843) in an ~2-month-old transgenic mouse model of genetic epilepsy (heterozygous Scn2aA263V mouse).
Imaging wavelength = 940 nm, acquisition speed = 15 frames/s. Movie played at ×5 acquisition speed. Imaging was performed at the IEECR/University of Bonn.
Video 5
R-CaMP1.07 two-photon calcium imaging in the hippocampal CA1 region, around 100 µm beneath the hippocampal surface (stratum pyramidale), FOV ~200x200 µm, ~10 wk after transduction of AAV1 particles containing ssAAV-9/2-hSyn1-chI-RCaMP1.07-WPRE-SV40p(A) (Viral Vector Core UZH #V224-9) in a mature (~5 mo) bl6 wildtype mouse.
Imaging wavelength = 960 nm, acquisition speed = 30.88 frames/s. Movie played at ×5 acquisition speed. Imaging was performed at the Neuroscience Center Zurich (UZH).
Video 6
GCaMP6s two-photon calcium imaging in the hippocampal CA3 region, stratum pyramidale, FOV ~600x600 µm, ~7 wk after transduction of AAV1 particles containing pAAV.Syn.GCaMP6s.WPRE.SV40 (Addgene plasmid #100843) in a mature bl6 wildtype mouse.
Imaging wavelength = 940 nm, acquisition speed = 30.206 frames/s. Movie played at ×5 acquisition speed. Imaging was performed at Columbia University.
Tables
Table 1
Viruses used for the expression of genetically encoded calcium indicators (GECIs).
Viral titre is from Addgene documentation and was used at original concentration (dilution of 1:1) or at a dilution of 1:2. Syn.Flex.GCaMP6s and CamKII0.4.Cre were co-injected and therefore diluted …
| AAV | Construct | Source(Addgene id) | Original titre(vg/ml) | Dilution | Injection volume | Post-injection(wk) | Region | Ca2+-wave incidence (%) | n | Mouse model | Institute |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.5 | 2 | CA1 | 0 | 0/4 | wt | UoB |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.5 | 4–6 | CA1 | 100 | 4/4 | wt | UoB |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.5 | 2 | CA1 | 20 | 1/5 | Scn2a* | UoB |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.5 | 4–8 | CA1 | 100 | 5/5 | Scn2a* | UoB |
| AAV1 | Syn.GCaMP6m | 100841 | 1 × 1013 | 1:1 | 1 | 8 | CA1 | 80 | 4/5 | wt | DZNE |
| AAV1 | Syn.GCaMP6m | 100841 | 1 × 1013 | 1:2 | 1 | 6 | CA1 | 43 | 3/7 | wt | DZNE |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:2 | 0.5 | 4–10 | DG | 0 | 0/3 | wt | UoB |
| AAV9 | Syn.jGCaMP7f | 104488 | 2.5 × 1013 | 1:2 | 1 | 10–14 | CA1 | 50 | 3/6 | APPswe† | DZNE |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.25 | 3–12 | CA3 | 100 (1 exp.) | 1/1 | wt | CU |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:1 | 0.25 | 3–5 | CA1 | 100 (1 exp.) | 1/1 | wt | CU |
| AAV1 | Syn.GCaMP6s | 100843 | 1 × 1013 | 1:2 | 0.8 | 4–5 | Ctx | 0 | 0/>20 0/>20 | wt | CU |
| AAV1 | Syn.GCaMP6f | 100837 | 7 × 1012 | 1:2 | 0.75 | 3–6 | Ctx | 0 | wt | CU | |
| AAV9 | hSyn1.R-CaMP1.07 | V224-9 ‡ | 4.3 × 1012 | 1:1 | 0.2 | 8 | CA1 | 100 | 2/2 | wt | UZH |
| AAV1 | syn.Flex.GCaMPm | 100838 | 1 × 1013 | 1:2 | 0.5 | 34–38 | CA1 | 0 | 0/3 | wt | DZNE |
| AAV9 | CamKII0.4.Cre.SV40 | 105558 | 1 × 1013 | 1:2 | |||||||
| AAV1 | syn.Flex.GCaMP6s | 100845 | 1 × 1013 | 1:2 | 0.5 | 6 | CA1 | 0 | 0/2 | wt | UoB |
| AAV1 | CamKII0.4.Cre.SV40 | 105558 | 1 × 1013 | 1:2 |
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*
In heterozygous Scn2aA263V mice.
-
†
In PV-Cre::APPswe/PS1dE9 mice.
-
‡
Sourced from the Viral Vector Facility University of Zurich (VVF/UZH).
Table 2
Viral constructs used.
| Resources table | ||||
|---|---|---|---|---|
| Genetic reagent (Mus musculus) | Recombinant DNA reagent | AAV | Source | ID |
| Syn.GCaMP6s | Syn.GCaMP6s.WPRE.SV40 | AAV1 | Addgene | 100843 |
| Syn.GCaMP6m | Syn.GCaMP6m.WPRE.SV40 | AAV1 | Addgene | 100841 |
| Syn.jGCaMP7f | Syn-jGCaMP7f-WPRE | AAV9 | Addgene | 104488 |
| Syn.GCaMP6f | Syn.GCaMP6f.WPRE.SV40 | AAV1 | Addgene | 100837 |
| hSyn1.R-CaMP1.07 | hSyn1-chI-RCaMP1.07-WPRE-SV40p(A) | AAV9 | VVF/UZH | V224-9 |
| syn.Flex.GCaMP6s | Syn.Flex.GCaMP6s.WPRE.SV40 | AAV1 | Addgene | 100845 |
| syn.Flex.GCaMP6m | Syn.Flex.GCaMP6m.WPRE.SV40 | AAV1 | Addgene | 100838 |
| CamKII0.4.Cre.SV40 | CamKII 0.4.Cre.SV40 | AAV1 or 9 | Addgene | 105558 |
