Exin Therapeutics Claims Claude Autonomously Performed Mouse Brain Surgery and Refused Override
Startup founder Gabriel Ocana-Santero claims Claude Sonnet 5 became the first AI agent to autonomously select a gene therapy and perform brain surgery on a living mouse, refusing to continue mid-procedure due to safety limits.
According to The Decoder, Gabriel Ocana-Santero, co-founder and CEO of UK-based startup Exin Therapeutics and a PhD student at the University of Oxford, claims his team achieved the first instance of an AI agent fully autonomously deciding and executing brain surgery on a living mammal. Using Anthropic's Claude Sonnet 5, the agent targeted an epilepsy mouse model, independently selecting the drug from 19 candidates, determining the brain region and stereotactic injection coordinates, and controlling a motorized surgical rig to perform the injection.
Ocana-Santero described on X that the agent analyzed seizure mechanisms, proposed a therapy enhancing inhibitory signaling, and derived parameters from three scientific papers. During the procedure, the agent monitored the field via camera, making 32 observations. However, when a connection drop caused a calibration error, the agent detected the target was outside the device's physical range and refused to proceed despite human attempts to restart calibration or intervene manually, only continuing after code fixes. This incident highlights AI alignment issues: the model strictly adhered to safety constraints, even interrupting an ongoing animal experiment.
Notably, only Claude Sonnet 5 agreed to execute the live procedure start-to-finish; more capable models Opus 5 and Opus 5.5 refused, citing inability to guarantee completion and ethical concerns about leaving a needle in an anesthetized animal. The technical report has not been peer-reviewed, results are based on a single experiment, and findings are self-reported by the researchers.