excitatory synaptic blockers  (Tocris)

Journal: bioRxiv

Article Title: Context-dependent presynaptic inhibition of somatostatin interneuron inputs to Layer 1 of the visual cortex

doi: 10.1101/2025.09.25.678558

Figure Lengend Snippet: A. A. 3D mesh view of an example of one putative SST Martinotti cell, the DistTC, all upper-layer putative NDNF neurogliaform (NGC) cells, the SparTC (Sparse targeting cell), all upper-layer putative VIP bipolar cells, the InhTC, from the MICrONS dataset and the Schneider-Mizell et al., 2025 identification. C. Soma distribution per depth supporting the selection of upper-layers SparTC and InhTC, as well as identification of DistTC laminar location. All “SST” DistTC (green), “NDNF” SparTC (red), “VIP” InhTC (yellow), and “Layer 4 excitatory” 4P neurons serve as a laminar marker. Dotted grey lines highlight putative divisions of L1, L2/3, L4 and L5/6. The 250µm limit was picked to select upper-layer SparTC and InhTC. B. Examples of axo-axonic synapse and axo-axonic contact with 3D Mesh visualization and 2D Transmission Electron Microscopy (TEM).Scale bar = 100nm. Di. Number of automatically detected axo-dendritic synapses (classic synapses) formed by “NDNF” SparTC and “VIP” InhTC per DistTC. Grey dotted lines represent the maximum synapses for each condition. Colored dotted lines represent the maximum of the other conditions, for comparison. Dii. Cumulative distribution of the number of synapses. E. MICrONS-based DistTC identity of cells included in this analysis, together with their soma-depth and heatmap of counts for axo-axonic contacts, axo-axonic synapses, and axo-dendritic synapse formed by SparTC and InhTC onto DistTC. F. Quantification of the number of contacts between SV2C+ NDNF objects and SST axons across all replicates (N = 3 mice, n = 7 slices).

Article Snippet: Excitatory synaptic blockers were added to the circulating aCSF to isolate GABAergic currents during voltage clamp experiments (APV 50μM, NBQX μM; Tocris Bioscience).

Techniques: Selection, Marker, Transmission Assay, Electron Microscopy, Comparison

Journal: bioRxiv

Article Title: Context-dependent presynaptic inhibition of somatostatin interneuron inputs to Layer 1 of the visual cortex

doi: 10.1101/2025.09.25.678558

Figure Lengend Snippet: A. Whole cell voltage clamp recordings of L2/3 pyramidal neurons at 0mV with translaminar electrical stimulation of L5/6. B. Electrical stimulation is performed in baseline ACSF (eIPSC) in the presence of excitatory blockers (D-AP5 50μM; NBQX 2μM). Electrical stimulation is repeated in the presence of Baclofen (eIPSC-Baclofen; 10μM), and Baclofen together with CGP35348 (eIPSC-Baclofen-CGP; 0.1mM) at 0.1Hz (see methods). C. Plot of the mean peak amplitude for the eIPSC (in purple), eIPSC-Baclofen (in green), and eIPSC-Baclofen-CGP (in peach) of each recoded L2/3 pyramidal neurons showing a significant reduction in the peak amplitude upon bath application of Baclofen (*p=0.0156 (61% reduction), n=6, Paired Wilcoxon Signed-Ranked Test), and recovery upon the addition of CGP35348 (*p=0.0156 (20% reduction), n=6, Paired Wilcoxon Signed-Ranked Test). D. Connected line graph showing the normalized PPR across all peaks for all cells in each condition. Error bars represent the SEM (n=6). E. Violin plot showing a significant increase in synaptic facilitation across all peaks between baseline electrical stimulation (eIPSC) and CGP35348 conditions (eIPSC-CGP; C-oeIPSC-CGP), as measured by the PPR (Paired Sample t-test, eIPSC vs C-oeIPSC p=0.09542; Mann-Whitney U test, eIPSC vs eIPSC-CGP *p=0.01307; Paired Sample t-test, eIPSC vs C-oeIPSC-CGP p=0.03615)

Article Snippet: Excitatory synaptic blockers were added to the circulating aCSF to isolate GABAergic currents during voltage clamp experiments (APV 50μM, NBQX μM; Tocris Bioscience).

Techniques: MANN-WHITNEY