Veterinary records show that as many as a dozen monkeys had to be euthanized after they were implanted with Neuralink devices because they developed agonizing complications, WIRED reported Wednesday. The monkeys’ issues included bloody diarrhea, partial paralysis, and cerebral edema, or “brain swelling.”
One monkey dislodged an implant connector because it kept yanking on the device. When veterinarians conducted surgery to repair the device, they found the implant area had become infected—and couldn’t be healed because the device was blocking their access.
Another monkey kept picking at her implant until it bled, and would repeatedly press her head to the floor in a sign of pain or discomfort. She became lethargic, opting to lie on the floor of her cage and hold hands with her roommate, until she saw lab workers. Then she would start to shake uncontrollably. After she was euthanized, a necropsy revealed the implant had severely damaged her brain.