Synaptic interactions between stellate cells and parvalbumin interneurons in layer 2 of the medial entorhinal cortex are organized at the scale of grid cell clusters
- Centre for Discovery Brain Sciences, University of Edinburgh, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, United Kingdom
- Institute of Medical Sciences, University of Aberdeen, United Kingdom
- Centre for Statistics, University of Edinburgh, United Kingdom
Figures
Figure 1
Organization of stellate cell axon collaterals.
(A–B) Examples of SCs reconstructed following patch-clamp recording from a sagittal (A) and horizontal (B) brain slice. Axons are in blue and dendrites in red. Traces to the right indicate membrane …
Figure 2 with 2 supplements
Asynchronous widefield activation strategy for investigating coordination between SCs and PV+ INs.
(A) Experimental strategy (left). To enable optical activation of SCs and targeted recording from PV interneurons, AAVs that express ChR2-eYFP conditionally on the presence of Cre and mCherry …
Figure 2—figure supplement 1
Optical ramp activation drives asynchronous activation of SCs.
Rasters of spike times (upper) from simultaneously recorded pairs of ChR2-expressing SCs in response to a ramp-modulated light stimulus, with corresponding cross-correlograms (lower left) and …
Figure 2—figure supplement 2
Simulation of SC inputs to PV+ interneurons.
(A, B) Simulation of EPSCs in PV+ interneurons (see Figure 2E) when 4 of 8 inputs from SCs to each PV+ interneuron also project to the other PV+ interneuron (A), and when all 8 inputs are …
Figure 3 with 2 supplements
Organization of correlated input from SCs to PV+ interneurons.
(A, B) Examples of simultaneously recorded EPSCs (upper) from pairs of PV+ interneurons and corresponding measures of the maximal correlation coefficient and correlation lag variance in response to …
Figure 3—figure supplement 1
Distribution of PV+ INs receiving correlated input from SCs.
(A, B) Heat maps of mean maximum cross-correlation coefficient as a function of time since light onset for the simultaneously recorded PV+ cells (left) and averaged variance of lags as a function of …
Figure 3—figure supplement 2
Testing for electrical and chemical synaptic connections between PV+ INs.
(A) Example of electrical connection between simultaneously recorded PV interneurons. Step current injection into either cell generates a large step change in membrane potential change in the …
Figure 4
Synaptic inhibition differentially contributes to coordination by SCs of nearby and distant PV+ interneurons.
(A) Simultaneously voltage-clamp recording, in the presence of GABAzine to block fast inhibition, of the responses of a pair of PV+ interneurons (upper traces) to ramping light (blue) activation of …
Figure 5 with 1 supplement
Focal activation of SCs confirms local direct connectivity to PV+ interneurons and reveals spatial organization.
(A) Schematic of experimental set up. Simultaneous whole-cell voltage-clamp recordings were made from pairs of PV+ inerneurons. ChR2-expressing SCs were activated by focal laser stimulation. (B) …
Figure 5—figure supplement 1
Focal activation of SCs.
(A) Examples of membrane potential responses of a ChR2-expressing SC to brief focal laser stimulation at low (left) and high (right) stimulation intensities. Each plot shows 5 overlaid responses. …
Figure 6
Organization of PV+ interneuron axons.
(A–B) Examples of reconstructed axonal (blue) and dendritic (red) morphology of PV+ interneurons in sagittal (A) and horizontal slices (B) (scale bar 200 µm). Axons are in blue and dendrites in red. …
Figure 7 with 1 supplement
Organization of correlated inputs from PV+ interneurons to SCs.
(A) Targeting of ChR2 to PV+ INs used Cre- or FLP-dependent AAVs injected into the MEC of PVCre or PVFlp mice. (B) Whole-cell recordings were targeted to pairs of principal cells in layer 2 of the …
Figure 7—figure supplement 1
Distribution of SCs receiving correlated input from PV+ INs.
(A–C) Left panel: heat maps of averaged maximum cross-correlation coefficient as a function of time since light onset for the simultaneously recorded SCs along the dorsal-ventral axis (A), the …
Figure 8
Model for organization of circuits in L2 of the MEC.
Direct interactions between SCs and PV+ INs define local clusters (see also Couey et al., 2013; Dhillon and Jones, 2000; Fuchs et al., 2016; Pastoll et al., 2012a; Winterer et al., 2017). …
