DEPPMANN & ZUNDER LABS · READABLE ATLAS

The developing brain mountain

Two complementary trajectory analyses · E11.5–P4

Conceptual Waddington landscape. Solid routes preserve published URD or summary relationships. Dashed links denote unsampled ancestry, alignment of overlapping analyses, or a putative state. Height, spacing and motion are illustrative. The apex represents a progenitor state, not a lineage-traced single cell.

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A mountain-shaped conceptual landscape with branching trajectories reaching labeled end states.

Van Deusen et al. · Nature Neuroscience · 2025 · Deppmann and Zunder labs · 26 modeled outcomes/profiles

All modeled end states and marker descriptions. Brain analyses overlap biologically.
End state	Markers	Interpretation	Evidence
Immature inhibitory neuronal progenitor	SOX2+; Nestin+ \| GAD65/GAD2-low; CTIP2/BCL11B-low; DCX-low	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
OLIG2-positive neuronal precursor	SOX2+; Nestin+ \| OLIG2-high; CTIP2/BCL11B-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Oligodendrocyte precursor · low Ki67	SOX2+; Nestin+ \| Ki67-low	A tip within the SOX2+ / Nestin+ progenitor analysis. Ki67 distinguishes this branch; it is not a stand-alone OPC gate.	Source
Oligodendrocyte precursor · low CD24	SOX2+; Nestin+ \| CD24-low	A tip within the SOX2+ / Nestin+ progenitor analysis. CD24 distinguishes this branch; it is not a stand-alone OPC gate.	Source
Oligodendrocyte precursor · CUX1-high	SOX2+; Nestin+ \| CUX1-high	CUX1 is the branch descriptor, not a stand-alone OPC identity marker. This remains an oligodendrocyte precursor.	Source
OLIG2-intermediate glial precursor	SOX2+; Nestin+ \| OLIG2-mid; BLBP/FABP7-high; GLAST/SLC1A3-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Astroglial precursor	SOX2+; Nestin+ \| GFAP-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
PAX6-low glial precursor	SOX2+; Nestin+ \| PAX6-low; OLIG2-low; GFAP-negative	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
PAX6-high glial precursor	SOX2+; Nestin+ \| PAX6-high; SOX2-low	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
PAX6-high neuronal progenitor	SOX2+; Nestin+ \| PAX6-high; NEUROD1-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Intermediate neuronal progenitor	SOX2+; Nestin+ \| EOMES/TBR2-high; PAX6-low	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Inhibitory neuronal precursor · BCL11B-low	SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-low	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Inhibitory neuronal precursor · BCL11B-high	SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Cycling inhibitory neuronal progenitor	SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-low; Ki67-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Glial progenitor · FABP7-high	PAX6-low; FABP7-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Astroglial precursor · GFAP-high	GFAP-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Oligodendrocyte precursor · PDGFRA-high	OLIG2-high; PDGFRA-high	One inferred cortical oligodendroglial route. OPCs remain precursors at the analysis tip.	Source
Glial precursor · OLIG2-low	OLIG2-low	An OLIG2-low glial precursor branch, not a mature oligodendrocyte. Late OLIG2 expression rises along this trajectory.	Source
Excitatory neuron · TBR1-low	TBR1-low; TUBB3+; RBFOX3+	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Excitatory neuron · TBR1-high / BCL11B-high	TBR1-high; BCL11B-high; TUBB3+	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Mixed neuronal precursor	GAD2-mixed; BCL11B-negative	Fig. 6c and 6h label this tip GAD2-mixed / BCL11B-negative. The inferred tree places it within the inhibitory-neuronal branch.	Source
Inhibitory interneuron · BCL11B-high	GAD2-high; BCL11B-high	Published analysis endpoint or summary outcome; common name is a readable gloss of the marker-defined state.	Source
Fibroblast-like nonneural cells	PDGFRA-high; GLAST/SLC1A3-low	The supplementary heatmap labels this profile Fibroblasts; the main panel retains broader nonneural cluster names. Supplementary Fig. 8k; marker context from 8e. The short terminal path represents the reported profile. The upstream dashed connection supplies developmental context; intermediate ancestry is unresolved.	Source
Other nonneural cells	Heterogeneous Nestin / N-Cadherin / CD133 profiles	The publication retains an unspecified common identity. The companion heatmap does not give a unique terminal marker combination; no precise gate is invented here. Supplementary Fig. 8k; marker context from 8e. The short terminal path represents the reported profile. The upstream dashed connection supplies developmental context; intermediate ancestry is unresolved.	Source
A2B5-positive endothelial cells	PECAM1/CD31+; A2B5-high	Endothelial identity is independent of the neural stem-cell trees. Supplementary Fig. 8k; marker context from 8e. The short terminal path represents the reported profile. The upstream dashed connection supplies developmental context; intermediate ancestry is unresolved.	Source
Ly6C-positive endothelial cells	PECAM1/CD31-high; Ly6C-high; CD133-low	Endothelial identity is independent of the neural stem-cell trees. Supplementary Fig. 8k; marker context from 8e. The short terminal path represents the reported profile. The upstream dashed connection supplies developmental context; intermediate ancestry is unresolved.	Source

Every annotated connection

Earlier common ancestor: Early embryonic epiblast progenitor. Destination profiles describe a state; they do not establish an increase or decrease from its parent.

All modeled connections, including inferred ancestry and analysis alignment
Connection	From → to	Marker annotation	Evidence and scope
Brain-wide progenitor analysis · shared root alignment	Common neural progenitor state → PAX6-positive neural stem cells	Destination profile: PAX6-high; SOX2+; Nestin+	Alignment of overlapping analyses. Alignment of overlapping analyses, not a biological fate bifurcation. Original published parent-child relationships are preserved below this point. Relationship source
Toward immature inhibitory neuronal progenitor	Interneuron progenitors → Immature inhibitory neuronal progenitor	Destination profile: SOX2+; Nestin+ \| GAD65/GAD2-low; CTIP2/BCL11B-low; DCX-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward olig2-positive neuronal precursor	Neuronal progenitors → OLIG2-positive neuronal precursor	Destination profile: SOX2+; Nestin+ \| OLIG2-high; CTIP2/BCL11B-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial / opc branch	Neural progenitors → Glial / OPC branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendrocyte precursor branch	Glial / OPC branch → Oligodendrocyte precursor branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendrocyte precursor	Oligodendrocyte precursor branch → Oligodendrocyte precursor · low Ki67	Destination profile: SOX2+; Nestin+ \| Ki67-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendrocyte precursor	Oligodendrocyte precursor branch → Oligodendrocyte precursor · low CD24	Destination profile: SOX2+; Nestin+ \| CD24-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial precursor branch	Glial / OPC branch → Glial precursor branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial progenitors	Glial precursor branch → Glial progenitors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial differentiation branch	Glial progenitors → Glial differentiation branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward opc / glial precursor branch	Glial differentiation branch → OPC / glial precursor branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward neural progenitors	PAX6-positive neural stem cells → Neural progenitors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendrocyte precursor	OPC / glial precursor branch → Oligodendrocyte precursor · CUX1-high	Destination profile: SOX2+; Nestin+ \| CUX1-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward olig2-intermediate glial precursor	OPC / glial precursor branch → OLIG2-intermediate glial precursor	Destination profile: SOX2+; Nestin+ \| OLIG2-mid; BLBP/FABP7-high; GLAST/SLC1A3-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward astroglial precursor	Glial differentiation branch → Astroglial precursor	Destination profile: SOX2+; Nestin+ \| GFAP-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward pax6-low glial precursor	Glial progenitors → PAX6-low glial precursor	Destination profile: SOX2+; Nestin+ \| PAX6-low; OLIG2-low; GFAP-negative	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward pax6-high glial precursor	Glial precursor branch → PAX6-high glial precursor	Destination profile: SOX2+; Nestin+ \| PAX6-high; SOX2-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward pax6-high neuronal progenitor	PAX6-positive neural stem cells → PAX6-high neuronal progenitor	Destination profile: SOX2+; Nestin+ \| PAX6-high; NEUROD1-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward intermediate neuronal progenitor	PAX6-positive neural stem cells → Intermediate neuronal progenitor	Destination profile: SOX2+; Nestin+ \| EOMES/TBR2-high; PAX6-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward neuronal progenitors	Neural progenitors → Neuronal progenitors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward interneuron progenitors	Neuronal progenitors → Interneuron progenitors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward interneuron progenitors	Interneuron progenitors → Interneuron progenitors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward interneuron precursors	Interneuron progenitors → Interneuron precursors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward inhibitory neuronal precursor	Interneuron precursors → Inhibitory neuronal precursor · BCL11B-low	Destination profile: SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward inhibitory neuronal precursor	Interneuron precursors → Inhibitory neuronal precursor · BCL11B-high	Destination profile: SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward cycling inhibitory neuronal progenitor	Interneuron progenitors → Cycling inhibitory neuronal progenitor	Destination profile: SOX2+; Nestin+ \| GAD65/GAD2-high; CTIP2/BCL11B-low; Ki67-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Telencephalic analysis · shared root alignment	Common neural progenitor state → PAX6-high neural stem cells	Destination profile: PAX6-high	Alignment of overlapping analyses. Alignment of overlapping analyses, not a biological fate bifurcation. Original published parent-child relationships are preserved below this point. Relationship source
Toward glial precursors	Glial branch → Glial precursors	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial progenitor	Glial precursors → Glial progenitor · FABP7-high	Destination profile: PAX6-low; FABP7-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward astroglial precursor	Glial precursors → Astroglial precursor · GFAP-high	Destination profile: GFAP-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendroglial branch	Glial branch → Oligodendroglial branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward oligodendrocyte precursor	Oligodendroglial branch → Oligodendrocyte precursor · PDGFRA-high	Destination profile: OLIG2-high; PDGFRA-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial precursor	Oligodendroglial branch → Glial precursor · OLIG2-low	Destination profile: OLIG2-low	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward neuronal branch	PAX6-high neural stem cells → Neuronal branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward excitatory neuronal branch	Neuronal branch → Excitatory neuronal branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward excitatory neuron	Excitatory neuronal branch → Excitatory neuron · TBR1-low	Destination profile: TBR1-low; TUBB3+; RBFOX3+	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward excitatory neuron	Excitatory neuronal branch → Excitatory neuron · TBR1-high / BCL11B-high	Destination profile: TBR1-high; BCL11B-high; TUBB3+	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward inhibitory neuronal branch	Neuronal branch → Inhibitory neuronal branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward mixed neuronal precursor	Inhibitory neuronal branch → Mixed neuronal precursor	Destination profile: GAD2-mixed; BCL11B-negative	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward inhibitory interneuron	Inhibitory neuronal branch → Inhibitory interneuron · BCL11B-high	Destination profile: GAD2-high; BCL11B-high	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward glial branch	PAX6-high neural stem cells → Glial branch	No directional marker change transcribed for this segment.	URD. Published inferred trajectory topology; not lineage tracing. Relationship source
Toward fibroblast-like nonneural cells	Profiled maturation; origin unspecified → Fibroblast-like nonneural cells	Destination profile: PDGFRA-high; GLAST/SLC1A3-low	Supplementary trajectory profile. Published summary relationship or maturation profile. Relationship source
Nonneural ancestry · intervening stages unresolved	Early embryonic epiblast progenitor → Profiled maturation; origin unspecified	No upstream marker transition measured or supplied for this profile.	Inferred developmental context. Schematic connection to early embryonic ancestry. This supplementary profile has no published neural-parent link. No intervening germ-layer or cell-type sequence is asserted. Relationship source
Toward other nonneural cells	Profiled maturation; origin unspecified → Other nonneural cells	Destination profile: Heterogeneous Nestin / N-Cadherin / CD133 profiles	Supplementary trajectory profile. Published summary relationship or maturation profile. Relationship source
Nonneural ancestry · intervening stages unresolved	Early embryonic epiblast progenitor → Profiled maturation; origin unspecified	No upstream marker transition measured or supplied for this profile.	Inferred developmental context. Schematic connection to early embryonic ancestry. This supplementary profile has no published neural-parent link. No intervening germ-layer or cell-type sequence is asserted. Relationship source
Toward a2b5-positive endothelial cells	Profiled maturation; origin unspecified → A2B5-positive endothelial cells	Destination profile: PECAM1/CD31+; A2B5-high	Supplementary trajectory profile. Published summary relationship or maturation profile. Relationship source
Nonneural ancestry · intervening stages unresolved	Early embryonic epiblast progenitor → Profiled maturation; origin unspecified	No upstream marker transition measured or supplied for this profile.	Inferred developmental context. Schematic connection to early embryonic ancestry. This supplementary profile has no published neural-parent link. No intervening germ-layer or cell-type sequence is asserted. Relationship source
Toward ly6c-positive endothelial cells	Profiled maturation; origin unspecified → Ly6C-positive endothelial cells	Destination profile: PECAM1/CD31-high; Ly6C-high; CD133-low	Supplementary trajectory profile. Published summary relationship or maturation profile. Relationship source
Nonneural ancestry · intervening stages unresolved	Early embryonic epiblast progenitor → Profiled maturation; origin unspecified	No upstream marker transition measured or supplied for this profile.	Inferred developmental context. Schematic connection to early embryonic ancestry. This supplementary profile has no published neural-parent link. No intervening germ-layer or cell-type sequence is asserted. Relationship source
Neural specification · earlier stages omitted	Early embryonic epiblast progenitor → Common neural progenitor state	Earlier stages were not measured in this atlas.	Inferred developmental connection. Schematic neural ancestry spans omitted early developmental stages. The following two roots are aligned views of overlapping populations; they are not two mutually exclusive biological fates. Relationship source

Developmental time

Partial source-evidence preview. Only the selected Figure 6 root at E11.5 and eight selected P4 neural tips have recovered ages. Other stages of these states remain unknown, as do all Figure 5 segments and four nonneural profiles. The added epiblast ancestor is earlier context. Intermediate-stage findings are unassigned rather than dated from marker changes or pseudotime.

Incoming routes use their child state’s age evidence, not a measured transition time. The geometric axis is not calibrated to chronological age.

Source age evidence for every modeled state
State	Age evidence	Scope
PAX6-positive neural stem cells	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Immature inhibitory neuronal progenitor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
OLIG2-positive neuronal precursor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Glial / OPC branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Oligodendrocyte precursor branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Oligodendrocyte precursor · low Ki67	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Oligodendrocyte precursor · low CD24	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Glial precursor branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Glial progenitors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Glial differentiation branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
OPC / glial precursor branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Neural progenitors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Oligodendrocyte precursor · CUX1-high	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
OLIG2-intermediate glial precursor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Astroglial precursor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
PAX6-low glial precursor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
PAX6-high glial precursor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
PAX6-high neuronal progenitor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Intermediate neuronal progenitor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Neuronal progenitors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Interneuron progenitors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Interneuron progenitors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Interneuron precursors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Inhibitory neuronal precursor · BCL11B-low	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Inhibitory neuronal precursor · BCL11B-high	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Cycling inhibitory neuronal progenitor	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
PAX6-high neural stem cells	Supported samples / windows: E11.5. Other stages unknown.	Confirms the age of selected root cells. It does not establish that all cells assigned to URD segment 1 occur only at E11.5 or define when this state first or last exists.
Glial precursors	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Glial progenitor · FABP7-high	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Astroglial precursor · GFAP-high	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Oligodendroglial branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Oligodendrocyte precursor · PDGFRA-high	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Glial precursor · OLIG2-low	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Neuronal branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Excitatory neuronal branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Excitatory neuron · TBR1-low	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Excitatory neuron · TBR1-high / BCL11B-high	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Inhibitory neuronal branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Mixed neuronal precursor	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Inhibitory interneuron · BCL11B-high	Supported samples / windows: P4. Other stages unknown.	Confirms that the selected terminal population was sampled at P4. Earlier presence and the age distribution across the entire terminal URD segment remain unknown; P4 is not an onset date.
Glial branch	Age unassigned	The local figure presents mixed-age cells along URD segments, but current inputs contain no cell-to-segment age crosswalk or quantitative age distribution for this UID.
Fibroblast-like nonneural cells	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Profiled maturation; origin unspecified	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Other nonneural cells	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Profiled maturation; origin unspecified	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
A2B5-positive endothelial cells	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Profiled maturation; origin unspecified	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Ly6C-positive endothelial cells	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Profiled maturation; origin unspecified	Age unassigned	Supplementary profile context has no empirical stage-to-current-node mapping in the local build inputs; do not inherit P4 from the neural-only Fig. 6 selection.
Early embryonic epiblast progenitor	Earlier ancestry context; outside sampling	This node was added as schematic ancestry outside the measured atlas; do not assign it to a sampled atlas stage or infer its exact age from radial position.
Common neural progenitor state	Age unassigned	Added alignment of shared neural ancestry; a precise chronological age is unassigned. Do not copy the E11.5 sampled anchor from the downstream telencephalic analysis onto this schematic state.

E11.5 · Findings

The sampled starting population

The telencephalic reconstruction uses PAX6-high neural stem cells from E11.5 whole brain as its selected root. This sampling anchor does not date the origin of the state.

Figure 6b root selection and 6c branch 1

E12.5 · Findings