Figure 1.
ChR2 expression in FF and…
Figure 1.
ChR2 expression in FF and FB pathways between V1 and LM. A ,…
Figure 1.ChR2 expression in FF and FB pathways between V1 and LM. A, Section through layer 2/3 of flattened cerebral cortex showing ChR2 expressing FF connections from V1 to areas LM, AL, and LI. The asterisk marks the AAV2/1.CAG.ChR2-Venus.WPRE.SV40 injection site in V1. Arrows indicate ChR2-expressing terminal fields in LM, AL, and LI. Blue labeling represents callosally projecting neurons marked by retrograde transport of bisbenzimide from the opposite hemisphere. The dashed lines outline callosally connected cortex. Notice that areas LM, AL, and LI are contained in the large acallosal region lateral to V1. B, In situ image of ChR2 expression after AAV injection into LM (asterisk). Arrows indicate weakly labeled projections to V1 and AL. Blue labeling, outlined by the dashed lines, indicates callosally connected cortex. Dark branches represent blood vessels on the surface of the cortex. C, Coronal section showing ChR2-expressing FFV1→LM projection (green) terminating in layers 2/3, 4, and 5 of LM. Red cell bodies in layer 2–6 represent tdTomato-expressing PV neurons (yellow indicates overlap with ChR2-expressing fibers). Blue immunostaining represents m2AChR expression. Notice that the m2AChR-labeled band in layers 3 and 4 is wider in V1 than LM. The transition coincides with the V1/LM border. The inset shows uniform expression of tdTomato in a PV neuron. D, Coronal section showing ChR2-expressing FBLM→V1 projection (green) terminating most densely in layers 1, deep 5, and 6. Weaker projections terminate in layers 2/3, 4, and superficial 5. Retrobead-labeled neurons represent FFV1→LM-projecting Pyr cells. The inset shows the distinctive punctate pattern of retrobead labeling in layer 2/3 Pyr cells. A, anterior; M, medial; P, posterior; L, lateral; D, dorsal; RL, rostrolateral area; AM, anteromedial area; PM, posteromedial area.
Figure 2.
Identification of Pyr cells and…
Figure 2.
Identification of Pyr cells and PV neurons in slices of visual cortex. Differential…
Figure 2.Identification of Pyr cells and PV neurons in slices of visual cortex. Differential interference contrast image of Pyr cell (A) and PV neuron (D) with recording pipette (arrow) filled with Alexa 594 and biocytin (B, E). Current-clamp recording from retrobead-labeled FFV1→LM-projecting Pyr cell (B) shows that a depolarizing current step evokes an adapting (regular spiking) train of action potentials (C). Recording from a tdTomato-expressing PV neuron shows a nonadapting (fast spiking) train of spikes (F).
Figure 3.
sCRACM in pairs of Pyr…
Figure 3.
sCRACM in pairs of Pyr cells and PV neurons. Coronal slice through V1,…
Figure 3.sCRACM in pairs of Pyr cells and PV neurons. Coronal slice through V1, showing ChR2-expressing FBLM→V1 axon terminations (green). Blue dots indicate the 8–16 grid (50 μm spacing) in which laser photostimuli were applied. Whole-cell patch-clamp recordings were obtained from FFV1→LM-projecting Pyr cells in layers 2/3 (white), 4 (gray), 5 (black), and 6 (white) as well as in PV neurons (red) of layers 2/3 and 5. Pyr cells and PV neurons were filled with biocytin, dendrites were reconstructed and overlaid with the fluorescent image of the slice. EPSCsCRACM of pairs of Pyr and PV neurons recorded in the same layer (i.e., 2/3, 5) were used to compare the strengths of FBLM→V1 inputs.
Figure 4.
EPSC sCRACM maps of an…
Figure 4.
EPSC sCRACM maps of an FF V1→LM input to a pair of Pyr…
Figure 4.EPSCsCRACM maps of an FFV1→LM input to a pair of Pyr and PV neurons recorded in layer 2/3 of LM of the same slice. A, Whole-cell patch-clamp recordings of EPSCsCRACM from a retrobead-labeled FBLM→V1-projecting Pyr cell whose soma is represented by the gray triangle. Each trace corresponds to a response evoked by a laser photostimulus delivered to ChR2-expressing FFV1→LM axon terminals at specific locations of an 8 × 16 grid (50 μm spacing) aligned to the surface of cortex and extending across layers 1–6. Inset shows consecutive EPSCsCRACM, demonstrating that responses were reproducible across multiple trials. Ticks at the beginning and end of the traces indicate the window used for calculating the pixel values shown in the heat map shown in B. B, Heat map of FFV1→LM inputs to Pyr cell shown in A. The pixel values are proportional to the strength of synaptic input at a given location. The overlay of the biocytin-filled Pyr cell shows that the distribution of synaptic inputs largely coincides with the dendritic arbor. C, EPSCsCRACM map of FFV1→LM input to a nearby layer 2/3 PV neuron. Inset shows that responses were consistent across multiple trials. D, Shows the heat map of FFV1→LM responses from PV neuron, whose dendritic tree is well matched to the synaptically active region. Notice that FFV1→LM inputs to PV neuron are stronger than to the FBLM→V1-projecting Pyr cell.
Figure 5.
EPSC sCRACM maps of an…
Figure 5.
EPSC sCRACM maps of an FF V1→LM input to a pair of Pyr…
Figure 5.EPSCsCRACM maps of an FFV1→LM input to a pair of Pyr and PV neurons recorded in layer 5 of LM of the same slice. A, Whole-cell patch-clamp recordings of EPSCsCRACM from a retrobead-labeled FBLM→V1-projecting layer 5 Pyr cell whose soma is represented by the gray triangle. Each trace corresponds to a response evoked by a laser photostimulus delivered to ChR2-expressing FFV1→LM axon terminals at specific locations of an 8 × 16 grid (50 μm spacing) aligned to the surface of cortex and extending across layers 1–6. Inset shows consecutive EPSCsCRACM, demonstrating that responses were reproducible across multiple trials. Ticks at the beginning and end of the traces indicate the window used for calculating the pixel values shown in the heat map shown in B. B, Heat map of FFV1→LM inputs to Pyr cell shown in A. The pixel values are proportional to the strength of synaptic input at a given location. The overlay of the biocytin-filled Pyr cell shows that the distribution of synaptic inputs largely coincides with the basal dendritic tree. There are no inputs to the apical tuft in layer 1, consistent with the paucity of ChR2-expressing FFV1→LM projections (Fig. 1C). C, EPSCsCRACM map of FFV1→LM input to a nearby layer 5 PV neuron. Inset shows that responses were consistent across multiple trials. D, Shows the heat map of FFV1→LM responses from PV neuron, whose dendritic tree is well matched to the synaptically active region. Notice that FFV1→LM inputs to PV neuron are weaker than to Pyr cell.
Figure 6.
EPSC sCRACM maps of an…
Figure 6.
EPSC sCRACM maps of an FB LM→V1 input to a pair of Pyr…
Figure 6.EPSCsCRACM maps of an FBLM→V1 input to a pair of Pyr and PV neurons recorded in layer 2/3 of V1 of the same slice. A, Whole-cell patch-clamp recordings of EPSCsCRACM from a retrobead-labeled FFV1→LM-projecting Pyr cell, whose soma is represented by the gray triangle. Each trace corresponds to a response evoked by a laser photostimulus delivered to ChR2-expressing FF axon terminals at specific locations of an 8 × 16 grid (50 μm spacing) aligned to the surface of cortex and extending across layers 1–6. Inset shows consecutive EPSCsCRACM, demonstrating that responses are reproducible across multiple trials. Ticks at the beginning and end of the traces indicate the window used for calculating the pixel values shown in the heat map (B). B, Heat map of FBLM→V1 inputs to Pyr cell shown in A. The pixel values are proportional to the strength of synaptic input at a given location. Overlay of the FBLM→V1 input map with the biocytin-filled Pyr cell, showing that the distribution of inputs coincides mainly with the ascending dendritic arbor. C, EPSCsCRACM map of FBLM→V1 input to layer 2/3 PV neuron. Inset shows that responses are consistent across multiple trials. D, Represents the heat map of FBLM→V1 responses from PV neuron, whose dendritic tree overlaps with the synaptically active region. Notice that FBLM→V1 inputs to PV neuron and Pyr cell are similar.
Figure 7.
EPSC sCRACM maps of an…
Figure 7.
EPSC sCRACM maps of an FB LM→V1 input to a pair of Pyr…
Figure 7.EPSCsCRACM maps of an FBLM→V1 input to a pair of Pyr and PV neurons recorded in layer 5 of LM of the same slice. A, Whole-cell patch-clamp recordings of EPSCsCRACM from a retrobead-labeled FFV1→LM-projecting Pyr cell whose soma is represented by the gray triangle. Each trace corresponds to a response evoked by a laser photostimulus delivered to ChR2-expressing FFV1→LM axon terminals at specific locations of an 8 × 16 grid (50 μm spacing) aligned to the surface of cortex and extending across layers 1–6. Inset shows consecutive EPSCsCRACM, demonstrating that responses were reproducible across multiple trials. Ticks at the beginning and end of the traces indicate the window used for calculating the pixel values shown in the heat map shown in B. B, Heat map of FBLM→V1 inputs to Pyr cell shown in A. The pixel values are proportional to the strength of synaptic input at a given location. The overlay of the biocytin-filled Pyr cell shows that the distribution of synaptic inputs coincides with the basal dendrites in layer 5 and apical dendrites in layer 1. The synaptic inputs to layer 1 are consistent with dense ChR2-expressing FBLM→V1 projections to layer 1 (Fig. 1D). C, EPSCsCRACM map of FBLM→V1 input to a nearby layer 5 PV neuron. Inset shows that responses were consistent across multiple trials. D, Shows the heat map of FBLM→V1 responses from PV neuron, whose dendritic tree is well matched to the synaptically active region. Notice that FBLM→V1 inputs to PV neuron are weaker than to Pyr cell.
Figure 8.
Vertical and horizontal extent of…
Figure 8.
Vertical and horizontal extent of FF V1→LM and FB LM→V1 inputs to Pyr…
Figure 8.Vertical and horizontal extent of FFV1→LM and FBLM→V1 inputs to Pyr cells and PV neurons in layer 2/3 and 5. Optical density of ChR2-expressing FFV1→ LM (A) and FBLM→ V1 (D) inputs to different layers of V1 and LM, respectively. Mean (±SEM) EPSCsCRACM (scaled to peak response within layer), evoked by FFV1→LM and FBLM→V1 input to layer 2/3 and 5 Pyr cells (B, E) and PVs (C, F). Red lines indicate responses at different vertical locations. Stippled line indicates the location of the soma. Positive distances indicate sites approaching to the pia, negative distances point toward white matter (WM). Black lines indicate responses at different locations of the tangential plane. Positive indicates medial and negative indicates lateral. Scale bars: A, D, 100 μm.
Figure 9.
Balance of FF V1→LM input…
Figure 9.
Balance of FF V1→LM input strength to FB LM→V1 -projecting Pyr cells and…
Figure 9.Balance of FFV1→LM input strength to FBLM→V1-projecting Pyr cells and PV neurons. A, Comparison of FFV1→LM input (summed pixels of significant EPSCsCRACM) to pairs of layer 2/3 Pyr cells and PVs recorded in same slice from nine mice. Red lines in A and B represent the mean slope from zero. B, Comparison of FFV1→LM input (summed pixels of significant EPSCsCRACM) to pairs of layer 5 Pyr cells and PVs recorded in same slice from 10 mice. C, Relative size of FFV1→LM input to PVs and Pyr neurons in layers 2/3 and 5. Errror bars indicate SEM.
Figure 10.
Balance of FB LM→V1 input…
Figure 10.
Balance of FB LM→V1 input strength to FF V1→LM -projecting Pyr cells and…
Figure 10.Balance of FBLM→V1 input strength to FFV1→LM-projecting Pyr cells and PV neurons. A, Comparison of FBLM→V1 input (summed pixels of significant EPSCsCRACM) to pairs of layer 2/3 Pyr cells and PV neurons recorded in same slice from 10 mice. Red lines in A and B represent the mean slope from zero. B, Comparison of FBLM→V1 input (summed pixels of significant EPSCsCRACM) to pairs of layer 5 Pyr cells and PV neurons recorded in same slice from eight mice. C, Relative size of FBLM→V1 input to PV neurons and Pyr cells in layers 2/3 and 5. Error bars indicate SEM.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.3