Region. Hippocampal
CA1 — one stage of the trisynaptic circuit (entorhinal cortex → dentate gyrus → CA3 →
CA1 → subiculum → entorhinal cortex). CA1's main input is the CA3
Schaffer collaterals; it also gets direct entorhinal input and projects to the subiculum. Here only CA1 cells are modelled — CA3/entorhinal afferents enter as external drive.
Model. Full-scale human CA1 (Gandolfi, Mapelli, Solinas & Migliore; EBRAINS / EU Human Brain Project). The complete model is ~
5.28 million neurons (4.8M pyramidal + 0.48M interneurons, ~9% inhibitory). This explorer shows
all 5.28M neurons; the full connectome is ~41 billion synapses, so
wiring is a representative central-column subset (cells outside that column appear as points without wiring).
Neurons. PYR (pyramidal) are the excitatory principal cells — ~90% of CA1; they drive their targets and are the output of the region. Every other type is a
GABAergic interneuron (NGF, Ivy, and others) that locally
inhibits pyramidal cells. Cells are coloured by type (see legend).
Connections. Each "Findings tour" entry is one
pathway: a source cell type wiring to a target type (e.g. NGF→PYR). A wire is coloured by the cell it
comes from. Click any cell to trace its outgoing connections, broken down by target type. Click the
🧬 morphology button, then a cell, to see a representative reconstruction of its type.
Morphologies. The scaffold model stores only soma positions (no shapes). For visualization we attach one
representative published reconstruction per cell type from
NeuroMorpho.org (Ascoli et al., 2007; CA1, mostly mouse). These are representative of the type — not the individual modelled cell — and carry no quantitative claim. Per-type NeuroMorpho IDs and PMIDs are listed in CA1_morphology_sources.md.
What we found. Neurogliaform (
NGF) cells form a giant inhibitory
blanket over the pyramidal population — in this model via
distance-independent connectivity, so a single NGF cell reaches clear across CA1 while every other interneuron class stays local. NGF also
receives no pyramidal input in the model, so pyramidal activity cannot recruit it.
Ivy forms a second dendritic blanket but, unlike NGF,
receives pyramidal drive — a closed feedback loop. Select the
NGF blanket and then
Ivy blanket in the findings tour: the difference in wire length is the whole point, and it is visible without any statistics. Quantification is in preparation.
Activity. Not included in this public build. The spike data is an unpublished simulation run and is not ours to publish; the wiring shown here is derived from the published Gandolfi et al. (2023) model. If you have the spike file locally, "Load local .bin files instead" will play it.