Elon Musk's claim that no monkey died as a result of Neuralink implants contradicts records that show how the animals experienced brain swelling, paralysis, seizures, and other health effects, letter to SEC alleges

• Elon Musk's Neuralink used monkeys to test its brain chip that can connect to a device.
• Musk said on X, formerly Twitter, that "no monkeys died as a result of Neuralink's chips."

A group that advocates for ethical scientific research is asking the Securities and Exchange Commission to investigate Elon Musk for his recent claim that no monkeys have died as a result of Neuralink's brain chip.

The Physicians Committee for Responsible Medicine (PCRM), a nonprofit that has previously lodged complaints against Neuralink's conduct, asked the SEC in a letter obtained by WIRED magazine to investigate Musk for securities fraud for a statement he made on X, formerly Twitter, on September 10.

Musk, who co-founded the biotech startup in 2016, wrote in response to a user post that "no monkey has died as a result of a Neuralink implant" — a chip that aims to allow humans to connect to a device remotely.

"First our early implants, to minimize risk to health monkeys, we chose terminal moneys (close to death already)," Musk wrote on September 10, misspelling monkeys.

PCRM alleged in the SEC letter that "Musk knows that to be false."

Last year, PCRM revealed that it had obtained records from the University of California, Davis, where Neuralink's experiments were conducted, that they said showed how the monkeys experienced "extreme suffering as a result of inadequate animal care and the highly invasive experimental head implants during the experiments."

Documents and research notes from the university's California National Primate Research Center that were published on PCRM's website show that at least a dozen monkeys that had chips implanted experienced a range of health issues, including infections and brain swelling, before they were eventually euthanized.

Other health effects included paralysis, seizures, loss of coordination and balance, and depression, PCRM wrote in the SEC letter.

The experiments, PCRM says, involved an hourslong surgery and drilling two "dime-sized" holes in the side of the monkeys' heads to implant the device.

In one case, researchers noted that a 6-year-old female rhesus macaque, labeled "Animal 15," was observed occasionally "picking or even pulling at" the implants after receiving the surgery, documents showed. They also noted other behaviors such as possibly "head pressing" as well as the loss of balance and coordination.

Other times, the monkey would also hold hands and groom her "visual buddy."

In March 2019, the researchers noted a "cranial implant infection." Animal 15 was euthanized that month, documents showed.

Spokespersons for Neuralink and PCRM did not immediately respond to a request for comment.

The group also objected to Musk's claim that the monkeys used for the testing were "close to death."

"Monkey health records show that, while several animals had suffered physical trauma and been used previously in experiments at UC Davis, there is no evidence that they were 'close to death,' as Musk stated," PCRM wrote, noting that the rhesus macaques "often live to about 25 years in captivity."

The average age of the dozen monkeys that died during Neuralink's research was 7.25 years, the group said.

One former Neuralink employee who requested anonymity for fear of retaliation told WIRED magazine that Musk's claim of the monkeys being close to death was "ridiculous," if not a "straight fabrication."

The employee said that researchers needed up to a year for behavioral training with the monkeys in order to conduct Neuralink's experiment.

Andy Fell, a spokesperson for the University of California, Davis, declined to provide further comment outside of the school's statement issued last year.

"UC Davis did have a research collaboration with Neuralink, which concluded in 2020," the statement said. "The research protocols were thoroughly reviewed and approved by the campus's Institutional Animal Care and Use Committee (IACUC). The work was conducted by Neuralink researchers in facilities at the California National Primate Research Center at UC Davis. UC Davis staff provided veterinary care including round-the-clock monitoring of experimental animals. When an incident occurred, it was reported to the IACUC, which mandated training and protocol changes as needed."

PCRM noted in the letter to the SEC that Musk has over 157 million followers on X, "meaning the reach of his messages is immense and affects the perception of Neuralink by the general public and potential investors."

Musk was previously charged with securities fraud after he tweeted in 2018 that he would be taking Tesla private at $420 a share.

The SEC settled the charge under the stipulation that Musk step down as Tesla's chairman and pay a $40 million fine.

In a separate class action lawsuit, a jury determined that Elon Musk was not liable for misleading investors with his social media posts.