L6 corticothalamic axons in mouse cortex extend in phases—first elongating with…

L6 corticothalamic axons in mouse cortex extend in phases—first elongating within L6 and later branching translaminarly into L4—and form functional AMPA-receptor-containing synapses preferentially onto PV interneurons rather than the more numerous excitatory neurons of L6 and L4.

{
  "n": "developmental mouse cortex; sample size in figures",
  "doi": "10.1016/j.celrep.2025.116792",
  "claim": "L6 corticothalamic axons in mouse cortex extend in phases—first elongating within L6 and later branching translaminarly into L4—and form functional AMPA-receptor-containing synapses preferentially onto PV interneurons rather than the more numerous excitatory neurons of L6 and L4.",
  "cite_key": "GutmanWei2026",
  "evidence": "Developmental tracing of L6 CT axons in mouse cortex, paired recordings, and AMPA-receptor minimal-stimulation assays of cell-type-biased synaptogenesis.",
  "effect_size": "L6 CT synapses preferentially onto PV; rare onto excitatory cells; functional AMPA from outset, no detectable silent synapses",
  "text_access": "fulltext",
  "study_system": "mouse cortex developmental L6 CT connectivity",
  "argument_role": "supporting",
  "replication_status": "consistent with L6 CT functional output to L5a > L4 excitatory cells (Crandall 2014)",
  "claim_source_sentence": "Layer 6 corticothalamic neurons (L6CThNs) provide a striking example of preferential synaptic connectivity. In both L4 and L6, the intracortical axons of L6CThNs form frequent synaptic connections onto parvalbumin-positive (PV) inhibitory interneurons. In contrast, L6CThNs rarely synapse onto excitatory neurons, even though excitatory neurons far outnumber PV interneurons in both cortical layers.",
  "source_provenance_status": "ok",
  "replication_evidence_dois": [
    "10.1523/JNEUROSCI.1325-14.2014"
  ],
  "effect_size_source_sentence": "L6CThNs form functional AMPA-receptor-containing synapses preferentially onto PV interneurons. Silent L6CThN synapses are not detected."
}

[
  "paper:paper-d8c260dd6b59"
]

Layer 6 corticothalamic neurons (L6CThNs) provide a striking example of preferential synaptic connectivity. In both L4 and L6, the intracortical axons of L6CThNs form frequent synaptic connections onto parvalbumin-positive (PV) inhibitory interneurons. In contrast, L6CThNs rarely synapse onto excitatory neurons, even though excitatory neurons far outnumber PV interneurons in both cortical layers.

[
  {
    "ref": "paper:paper-d8c260dd6b59"
  }
]

{
  "mode": "public_source_pointer_with_short_context",
  "notes": [
    "Local review repositories are read-only inputs.",
    "SciDEX stores paper metadata, structured evidence, file pointers, and short citation contexts; it does not copy full review prose."
  ],
  "source_commit_sha": "79ce062d54a924ce05953ec90aa9d26044d2b48f",
  "source_repository_url": "https://github.com/AllenNeuralDynamics/ComputationalReviewRecurrence"
}