{
"axes": {
"x": "presynaptic layer",
"y": "postsynaptic layer",
"z": "connection probability"
},
"datasets": [
{
"doi": "10.1016/j.neuron.2008.12.020",
"method": "multi-patch paired recording across all 6 layers",
"system": "mouse C2 barrel column (S1)",
"value_summary": "Strongest excitatory influence on the column from presynaptic L4. Layer-pair P(conn) matrix is reported across all 6 layers in the paper's Figure 4 (verbatim numbers in source).",
"claim_source_sentence": "The strongest excitatory influence upon the cortical column was provided by presynaptic layer 4 neurons."
},
{
"doi": "10.1371/journal.pbio.1000572",
"method": "glutamate-uncaging laminar maps (CRACM-style)",
"system": "mouse vM1, vS1, S2",
"value_summary": "Conserved L2/3→L5 across vM1/vS1/S2; variable L4→L2/3 and L6 across areas.",
"claim_source_sentence": "The most conserved pathways were L2/3→L5, and the most variable were L4→L2/3 and pathways involving L6."
},
{
"doi": "10.7554/eLife.71103",
"method": "two-photon optogenetic stimulation + multi-patch",
"system": "mouse V1, L2/3 targets",
"value_summary": "Most common sources of input to L2/3 pyramidal cells are L4 excitatory + intra-L2/3 interneurons; strong but unexpected L5-IT→L2/3 excitatory connections.",
"claim_source_sentence": "Consistent with the canonical cortical microcircuit, layer 4 excitatory neurons and interneurons within L2/3 represented the most common sources of input to L2/3 pyramidal cells. More surprisingly, we also observed strong excitatory connections from layer 5 intratelencephalic neurons and potent translaminar inhibition from multiple interneuron subclasses."
},
{
"doi": "10.1016/j.xinn.2024.100735",
"method": "2P 'optomapping' — 30,454 candidate inputs",
"system": "mouse V1, all-layer targets",
"value_summary": "Across 1,790 excitatory inputs, log-normal efficacy distribution; pyramidal input recapitulates canonical L4→L2/3→L5; basket-cell excitation concentrated in L5; Martinotti-cell excitation dominated in L2/3.",
"claim_source_sentence": "In mouse primary visual cortex (V1), we optomapped 30,454 candidate inputs to reveal 1,790 excitatory inputs to pyramidal, basket, and Martinotti cells."
},
{
"doi": "10.1038/s41586-025-08840-3",
"method": "EM connectome + 2P functional imaging",
"system": "MICrONS mouse V1 + HVAs",
"value_summary": "Like-to-like connectivity holds within and across layers and areas, including feedback; feature component (not spatial) predicts fine-scale connections.",
"claim_source_sentence": "Our results reveal that neurons with similar response properties are preferentially connected within and across layers and areas-including feedback connections-supporting the universality of 'like-to-like' connectivity across the visual hierarchy."
}
],
"audit_issues": [
{
"dimension": "study_system",
"description": "Methods are heterogeneous: multi-patch paired recording (Lefort), glutamate-uncaging CRACM (Hooks/Shepherd), 2P-optogenetic + multipatch (eLife 71103), 2P 'optomapping' (Inn 2024), and EM functional connectomics (MICrONS). Each technique samples a different connection definition (intersomatic vs. axodendritic vs. synaptic-density).",
"entries_affected": [
"10.1016/j.neuron.2008.12.020",
"10.1371/journal.pbio.1000572",
"10.7554/eLife.71103",
"10.1016/j.xinn.2024.100735",
"10.1038/s41586-025-08840-3"
]
},
{
"dimension": "scope_region",
"description": "Rows cover mouse S1 barrel column, vM1/vS1/S2, V1 only, V1, and V1+HVAs. Matrix entries are not from a single cortical area.",
"entries_affected": [
"10.1016/j.neuron.2008.12.020",
"10.1371/journal.pbio.1000572",
"10.7554/eLife.71103",
"10.1016/j.xinn.2024.100735",
"10.1038/s41586-025-08840-3"
]
},
{
"dimension": "scope_population",
"description": "Postsynaptic targets differ (all layers vs. L2/3 only vs. pyramidal+basket+Martinotti), so matrix coverage is not uniform across rows.",
"entries_affected": [
"10.7554/eLife.71103",
"10.1016/j.xinn.2024.100735"
]
}
],
"audit_verdict": "CAVEAT",
"figure_concept": "Translaminar E→E connection probability matrices across mouse cortical areas (paired-recording / opto-mapping)",
"interpretation_note": "Numeric P(conn) values for individual layer pairs are taken from each paper's main figure; the comparison places mouse barrel-column paired-recording matrices (Lefort 2009) alongside laminar maps in motor/somatosensory/secondary-somatosensory cortex (Weiler 2011), two-photon optogenetic translaminar inputs in V1 (Apicella 2022, Lan 2024), and the MICrONS structural-functional cortical reconstruction.",
"mandatory_caption_caveats": [
"Studies use different connection definitions (paired patch, glutamate uncaging, 2P optogenetics, optomapping, EM); reported P(conn) values reflect different sampling biases and are not directly comparable.",
"Rows span mouse S1, vM1/vS1/S2 and V1; the matrix is assembled across areas, not within one."
]
}