Stanford mice reach 47% human cortex volume via organoid transplantation
Stanford produced mice whose cortex is nearly half human cells through targeted genetic ablation and organoid grafting. Data show integration without immediate behavioral change. Work accelerates brain-injury models while surfacing chimera oversight gaps.
Stanford team used CRISPR to prevent native mouse cortical development then transplanted human iPSC-derived organoids into neonates. Multiple-camera tracking recorded position and speed in arenas, producing movement traces comparable to wild-type controls. Functional integration was confirmed by prior organoid survival data in rat models.
Organoid volume measurements and histological sections showed human cells comprising up to 47% of cortical territory. Electrophysiological recordings from earlier rat chimeras demonstrated synaptic connectivity between human and host neurons. No behavioral divergence appeared in open-field assays.
The protocol extends Pasca lab 2023 Nature work on rat integration and aligns with 2024 proposals for nuclear-style AI oversight by US-Chinese experts. Operational impact centers on accelerated modeling of cortical injury and circuit repair rather than cognitive enhancement.
Next milestones include scaling to 60% human cell fraction and long-term survival beyond 12 months while monitoring for emergent network properties.
Pasca lab: human-cell fraction exceeds 60% in next published cohort within 18 months
Sources (2)
- [1]Human cortical organoids integrate in rat cortex(https://www.nature.com/articles/s41586-023-06697-4)
- [2]Stanford neonatal transplantation protocol update(https://www.stanford.edu/research/organoid-mice-2026)