Supramammillary nucleus synchronizes with dentate gyrus to regulate spatial memory retrieval through glutamate release
- Department of Pharmacology, University of North Carolina, United States
- Neuroscience Center, University of North Carolina, United States
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Japan
- The McGovern Institute for Brain Research, Massachusetts Institute of Technology, United States
- Neurobiology Curriculum, University of North Carolina, United States
- Department of Neurology and Biomedical Research Imaging Center, University of North Carolina, United States
Figures
Figure 1 with 2 supplements
Ca2+ activities of the SuM and DG at home cage and during the spatial memory test.
(A) Experimental diagram of the DG and SuM calcium recording at the home cage. (B) Coronal sections showing photometry fiber traces and CaMKII-GCaMP/tdTomato expressed neurons in the DG (left) and …
Figure 1—figure supplement 1
Experimental protocol of fiber photometry recording.
(A) Schematic illustration of the photometry system used for measuring red and green fluorescent sensors in the SuM and DG. CaMKII-GCaMP6f and CAG-tdTomato were delivered to the left DG and SuM. (B) …
Figure 1—figure supplement 2
Low correlation of GCaMP activity in EC and DG at home cage and during the NPR test.
(A) Experimental diagram of the DG and EC calcium recording. (B) Coronal sections showing photometry fiber traces and CaMKII-GCaMP/tdTomato expressing neurons in the DG (left) and EC (right). Scale …
Figure 2 with 3 supplements
SuM activity is required for spatial memory retrieval.
(A) Experimental scheme. Coronal sections showing mCherry expression in SuMLVgat neurons in Vgat-Cre mice. Scale bar = 100 µm. (B) Sample images showing the c-Fos expression in SuMLVgat neurons 1 hr …
Figure 2—figure supplement 1
Cell-type-specific anterograde and retrograde tracing for SuMVgat-DG connections.
(A) Diagram of rabies-based monosynaptic synaptic tracing of DG GCs. (B) Experimental timeline of retrograde tracing. On day 1, AAV-CaMKII-Cre, Cre-dependent TVA-GFP and RG virus were injected to …
Figure 2—figure supplement 2
Locomotor activity after activity manipulation of SuMVgat neurons.
Locomotor activity in the open field (5 mins, same for both NPR and NOR tests) was recorded 1 hr after CNO administration in mice injected with AAVs expressing mCherry-, hM3Dq- or hM4Di. (A-B) …
Figure 2—figure supplement 3
Stimulation of SuMM neurons did not significantly increase spatial memory.
(A) Schematic diagram of the viral delivery. AAV5-CaMKII-mCherry (150 nL) was injected to the SuMM. (B) The representative image showing mCherry expression preferentially in the SuMM. (C) …
Figure 3 with 2 supplements
Activity of SuMVgat-DG projections is required for spatial memory retrieval.
(A) Schematic diagram of the experimental design. Cre-dependent ChR2-mCherry was injected in the SuM of Vgat-Cre mice. Terminals of the infected SuM GABAergic neurons were photo-stimulated, and …
Figure 3—figure supplement 1
Functional expression of Arch in SuMVgat neurons.
(A) Left, schematic diagram of optogenetic inhibition of SuMVgat neurons in the acute brain slices; Right, Live differential interference contrast (DIC) and the fluorescence image from whole-cell …
Figure 3—figure supplement 2
Optogenetic activation of SuMVgat-CA2 projections did not change the discrimination ratio in the NPR test.
(A) Diagram of optogenetic activation of SuMVgat-CA2 projections. AAV5-DIO-ChR2-mCherry was injected into the SuML and bilateral fibers were implanted above the CA2 in Vgat-Cre mice. (B) Coronal …
Figure 4 with 1 supplement
SuM glutamate transmission modulates dentate granule cell activity.
(A) Schematic diagram of the experimental design. Cre-dependent AAV-ChR2-mCherry mixed with AAV-shVgat or AAV-shVglut2 was injected in the SuM of Vgat-Cre mice. Terminals of the infected SuM …
Figure 4—figure supplement 1
Genetic knockdown of Vgat and Vglut2 in SuMVgat neurons.
Immunohistochemical staining of Vgat or Vglut2 in DG synaptic terminals emanating from SuMVgat neurons. After shVgat and shVglut2 expression in the SuM, Vgat and Vglut2 expression from SuMVgat-DG …
Figure 5
SuM glutamate transmission is necessary for spatial memory retrieval.
(A) Schematic diagram of genetic knockdown of Vgat or Vglut2 in SuM neurons. (B–C) Knocking down Vglut2 (B) but not Vgat (C) decreased discrimination ratio in the NPR test. (B, unpaired t-test, t14 =…
Figure 6
SuM glutamate transmission is necessary for regulating DG activity and establishing high SuM-DG synchrony during spatial memory retrieval.
(A) Experimental diagram of the DG and SuM Ca2+ recording under expressing shVglut2 in the SuM. (B) Coronal sections showing fiber photometry traces and CaMKII-GCaMP/tdTomato expressed neurons in …
Figure 7
Summary model of a long-range SuM-DG circuit linking two highly correlated subcortical regions to regulate spatial memory retrieval through SuM glutamate tranmission.
(A) Correlation of the SuM and DG Ca2+ activity is increased during spatial memory retrieval. (B) SuM glutamate transmission is necessary for the high correlation of the SuM and DG activities. (C) …
Author response image 1
The time lag between the SuM and DG calcium activities.
(A) Scaled color plot of the SuM and DG calcium activity. (B) Averaged DG and SuM calcium activities. (C) Cross correlation of the DG and SuM calcium activities during the exploring phase (2 s). The …
Tables
Key resources table
| Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|
| Strain, strain background (Mus musculus, C57BL6/J) | Slc32a1tm2(cre)Lowl/J, (Bl6) | Jackson laboratory | JAX: 016962 | All sexes used |
| Strain, strain background (Mus musculus, C57BL6/J) | Mouse: C57BL/6J | Jackson laboratory | RRID: IMSR_JAX:000664 | All sexes used |
| Strain, strain background (adeno-associated virus) | AAV5-EF1α-FLEX-TVA-mCherry | Massachusetts Institute of Technology | Dr. Ian R. Wickersham | |
| Strain, strain background (adeno-associated virus) | AAV-CA-FLEX-RG | Massachusetts Institute of Technology | Dr. Ian R. Wickersham | |
| Strain, strain background (rabies virus) | RABV-SAD∆G-mCherry | Massachusetts Institute of Technology | Dr. Ian R. Wickersham | |
| Strain, strain background (adeno-associated virus) | AAV5-EF1α-DIO-eYFP | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV5-EF1α-DIO-mCherry | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV5-EF1a-DIO-hChR2(H134R)-mCherry | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV5-EF1a-DIO-Arch 3.0-eYFP | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV5-hSyn-DIO-hM3Dq-mCherry | addgene | #50474-AAV5 | |
| Strain, strain background (adeno-associated virus) | AAV5-hSyn-DIO-hM4Di-mCherry | addgene | #50475-AAV5 | |
| Strain, strain background (adeno-associated virus) | AAV5-CaMKII-GCaMP6f | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV2-CaMKII-tdTomato | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV5-CaMKII-hM3Dq-mCherry | UNC Vector Core | ||
| Strain, strain background (adeno-associated virus) | AAV8-hsyn-DIO-shVgat-mCherry | University of Tsukuba | Dr. Michael Lazarus | |
| Strain, strain background (adeno-associated virus) | CMV-shVglut2-mCherry | University of Tsukuba | Dr. Michael Lazarus | |
| Antibody | Donkey polyclonal Anti- c-Fos | Millipore | Cat# 3168266; RRID: ABE457 | 1:1 k |
| Antibody | Rabbit polyclonal Anti- GABA | Sigma | Cat# A2052-100UL | 1:1 k |
| Antibody | Goat polyclonal Anti- GPF | Rockland | Cat# 600-101-215; RRID: AB_218182 | 1:1 k |
| Antibody | Rabbit polyclonal Anti-Vgat | Synaptic Systems | Cat#131002, RR:131003/32 | 1:1 k |
| Antibody | Guinea pig Polyclonal Anti-Vglut2 | Millipore | Cat# 3101508; RRID: AB2251-I | 1:1 k |
| Chemical compound, drug | Clozapine-N-oxide (CNO) | Sigma | Cat# C0832-5MG | |
| Software, algorithm | ImageJ (Fiji) | http://fiji.sc/ | ||
| Software, algorithm | FV3000 | Olympus | ||
| Software, algorithm | Ocean view | Ocean Optics | ||
| Software, algorithm | GraphPad Prism | GraphPad Software | Prism 8 | |
| Software, algorithm | Matlab | MathWorks | R2014b | |
| Software, algorithm | EthoVision XT | Noldus |
