A Monkey Had 20 Screws in His Brain for Weeks. The Professor Who Did It Still Has His Job.


A Monkey Had 20 Screws in His Brain for Weeks. The Professor Who Did It Still Has His Job.
The Issue
Everett was a rhesus macaque at the University of Minnesota. He was lethargic. One arm was weak. His hair was thinning rapidly. He vomited. His eyes moved abnormally. He pressed his head against the bars of his cage again and again, seeking relief from what insiders now know was a crushing headache caused by approximately 20 metal screws that had been drilled so deeply into his skull they pierced his brain.
The professor who performed the botched surgery, neuroscience researcher Jan Zimmermann, is not a surgeon. According to university insiders who shared their accounts with PETA, he spent months concealing what he had done. He deleted a brain scan of a second monkey with similarly protruding screws. He deleted notes made by a laboratory employee about Everett's deteriorating condition, including the words: "I'm getting pretty worried about him, and what the hell may be going on." He told colleagues he had shared the results with a veterinarian and that no neurological problems were found. That was a lie. Only when a veterinarian threatened to report him to the university's oversight committee did Zimmermann disclose Everett's condition. Everett was eventually killed.
Jan Zimmermann still has his surgical privileges. He still conducts experiments on monkeys.
Geoff Ghose, a fellow neuroscience professor whose laboratory has seen a monkey named Gandalf have his headpost sheared from his skull during a cage transfer and a monkey named Bilbo have his brain punctured, a metal bar jammed into his eye during surgery, and his exposed brain left without treatment for three days while the veterinarian said he "wanted to think," was temporarily suspended and stripped of the privilege to run his own laboratory. He is still allowed to conduct experiments on monkeys in other laboratories.
This is what accountability looks like at the University of Minnesota for researchers who drill screws into monkey brains, conceal botched surgeries, delete evidence, and lie to colleagues.
It gets worse. The federal government is funding this. NIH has awarded these experiments with taxpayer money, including $1 million to NeuralThread, a for-profit San Francisco company where Zimmermann also sells his skills. The university's own animal experimentation oversight committee brushed aside insiders' ethical concerns. The USDA was initially indifferent when insiders went to federal authorities. NIH glossed over a detailed complaint documenting each problematic surgery, each experimenter, each monkey, and each date. Only after one individual inspector reviewed the situation did the USDA finally issue a damning report against the university.
Every level of oversight failed Everett. Every level of oversight failed Gandalf. Every level of oversight failed Bilbo. And every American taxpayer is currently funding the institution and the researchers responsible.
PETA is calling for an immediate end to Ghose's and Zimmermann's experiments, for NIH to stop funding them, and for NeuralThread to cut ties with Zimmermann. Those demands are right. But they are not enough without a full independent investigation into how every level of oversight, from the university committee to the USDA to NIH, failed to act on documented evidence of animal cruelty and concealment for so long.
Sign this petition to demand the University of Minnesota permanently bar Jan Zimmermann and Geoff Ghose from conducting any further experiments on animals, call on NIH to immediately terminate all grants supporting their research and strengthen oversight of federally funded animal experiments, and demand a full independent investigation into the institutional failures that allowed this documented cruelty to continue unchecked.
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The Issue
Everett was a rhesus macaque at the University of Minnesota. He was lethargic. One arm was weak. His hair was thinning rapidly. He vomited. His eyes moved abnormally. He pressed his head against the bars of his cage again and again, seeking relief from what insiders now know was a crushing headache caused by approximately 20 metal screws that had been drilled so deeply into his skull they pierced his brain.
The professor who performed the botched surgery, neuroscience researcher Jan Zimmermann, is not a surgeon. According to university insiders who shared their accounts with PETA, he spent months concealing what he had done. He deleted a brain scan of a second monkey with similarly protruding screws. He deleted notes made by a laboratory employee about Everett's deteriorating condition, including the words: "I'm getting pretty worried about him, and what the hell may be going on." He told colleagues he had shared the results with a veterinarian and that no neurological problems were found. That was a lie. Only when a veterinarian threatened to report him to the university's oversight committee did Zimmermann disclose Everett's condition. Everett was eventually killed.
Jan Zimmermann still has his surgical privileges. He still conducts experiments on monkeys.
Geoff Ghose, a fellow neuroscience professor whose laboratory has seen a monkey named Gandalf have his headpost sheared from his skull during a cage transfer and a monkey named Bilbo have his brain punctured, a metal bar jammed into his eye during surgery, and his exposed brain left without treatment for three days while the veterinarian said he "wanted to think," was temporarily suspended and stripped of the privilege to run his own laboratory. He is still allowed to conduct experiments on monkeys in other laboratories.
This is what accountability looks like at the University of Minnesota for researchers who drill screws into monkey brains, conceal botched surgeries, delete evidence, and lie to colleagues.
It gets worse. The federal government is funding this. NIH has awarded these experiments with taxpayer money, including $1 million to NeuralThread, a for-profit San Francisco company where Zimmermann also sells his skills. The university's own animal experimentation oversight committee brushed aside insiders' ethical concerns. The USDA was initially indifferent when insiders went to federal authorities. NIH glossed over a detailed complaint documenting each problematic surgery, each experimenter, each monkey, and each date. Only after one individual inspector reviewed the situation did the USDA finally issue a damning report against the university.
Every level of oversight failed Everett. Every level of oversight failed Gandalf. Every level of oversight failed Bilbo. And every American taxpayer is currently funding the institution and the researchers responsible.
PETA is calling for an immediate end to Ghose's and Zimmermann's experiments, for NIH to stop funding them, and for NeuralThread to cut ties with Zimmermann. Those demands are right. But they are not enough without a full independent investigation into how every level of oversight, from the university committee to the USDA to NIH, failed to act on documented evidence of animal cruelty and concealment for so long.
Sign this petition to demand the University of Minnesota permanently bar Jan Zimmermann and Geoff Ghose from conducting any further experiments on animals, call on NIH to immediately terminate all grants supporting their research and strengthen oversight of federally funded animal experiments, and demand a full independent investigation into the institutional failures that allowed this documented cruelty to continue unchecked.
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Petition created on 13 April 2026