Sylvain Lesné

Sylvain E. Lesné (born 1974) is a French neuroscientist and former associate professor at the Department of Neuroscience at the University of Minnesota (UMN) Medical School, known for his research in Alzheimer's disease. He is the primary author of a controversial 2006 Nature paper, "A specific amyloid-β protein assembly in the brain impairs memory". Responses from other researchers indicated that, while the allegations were significant, the overall impact on amyloid research was small and most Alzheimer's research was not compromised. Other researchers disagreed, and expressed concerns that the doctored images raised doubts about the amyloid hypothesis.

Personal life and education Sylvain E. Lesné was born in 1974 and raised in Luc-sur-Mer, a small town in the Normandy region in northwestern France. His parents are Bertrand and Marie Carmen Lesné.

Jill Caroline, a Minnesota psychologist and special educator, and Lesné were married in Beauvoir-sur-Mer, France on August 14, 2010.

Early career Denis Vivien, a French cell biologist and neuroscience professor who oversaw Lesné's doctoral work by Karen Ashe at the University of Minnesota. Ashe in turn has described Lesné as her "brilliant postdoctoral fellow"; he had claimed to have developed a means of measuring amyloid beta (Aβ) oligomer proteins separately inside and outside of cells. Dennis J. Selkoe, another Alzheimer's researcher, has questioned this method, saying that "it made no biochemical sense". He received $774,000 in NIH grants to study Aβ*56 through 2012, in addition to over $7 million for Alzheimer's research through 2022. He was an associate director at the UMN's N. Bud Grossman Center for Memory Research and Care, where Ashe serves as director. , he was a scholar at the UMN's Institute for Translational Neuroscience.

Lesné resigned from his tenured position at UMN effective March 1, 2025, after a UMN investigation flagged "data integrity" concerns in other articles he authored.

Alzheimer's research Lesné is the lead author, with Ashe and others as co-authors, of a controversial 2006 report published in Nature. The study proposed that Aβ*56 was responsible for the memory deficits that occur in Alzheimer's. The Daily Telegraph states that the "seminal research paper" led to increased drug research funding worldwide. For the paper, Lesné was listed as of May 13, 2022 at UMN Medical School's Wall of Scholarship recognizing faculty who "must have first or last author credits on a publication that has been cited at least 1,000 times".

Other scientists have not been able to replicate the results specific to Aβ*56 and whether it exists is questioned; as of May 2023, according to the Minneapolis Star Tribune, images have been questioned on 20 articles he has authored. Another journal, Science Signaling, had issued two expressions of concern, and two other journals,The Journal of Neuroscience and Brain, have issued corrections on articles associated with Lesné and his UMN co-workers. was retracted after a UMN investigation found the concerns about manipulated images were valid.

Retraction Watch states that Ashe co-authored some of the disputed papers, and that the authors in the disputed work do not overlap except for two from UMN Department of Neuroscience. Alzheimer's researcher John Forsayeth commented that Ashe had been guilty of a "major ethical lapse" in oversight of data and Dennis Selkoe, a Harvard Medical School neurologist, said he did not understand how Ashe failed to "hyperscrutinize" data considering reactions to the 2006 Nature report. Piller writes that Lesné's work was already being queried before his investigation, when other researchers were unable to replicate the results. The Daily Telegraph states that the "authors of the Minnesota paper have defended their original findings" and support the role of amyloid as a cause of Alzheimer's. She stated via email that "... the figures in question were manipulated in a way that made them look nicer but did not affect one word in the paper".

2024 retraction In May 2023, the Star Tribune reported that the senior author of the study, Karen Ashe, was using new techniques to re-do the work reported in the 2006 Nature study, this time without Lesné, and that she stated "it's my responsibility to establish the truth of what we've published".

In May 2024, Ashe announced that the 2006 publication would be retracted, although she stated that the manipulated images did not affect the study's conclusions; according to Retraction Watch, this makes it the second most highly cited paper ever retracted.

Impact on Alzheimer's research Responses from some researchers in 2022 indicated that, while the allegations were significant, the overall impact on amyloid research was small and most Alzheimer's research was not compromised. Other researchers disagreed, and expressed concerns that the doctored images raised doubts about the amyloid hypothesis. France, state that the general theory behind the amyloid hypothesis remains valid. Selkoe, who Science describes as "a leading advocate of the amyloid and toxic oligomer hypotheses", opined that the "broader amyloid hypothesis remains viable" and referred to the alleged image manipulation as "what really looks like a very egregious example of malfeasance that's squarely in the Aβ oligomer field".

Following Lesné's 2025 resignation, Schrag was critical of the delay. According to Piller, Schrag stated: "Accountability [was] long overdue. The University of Minnesota's inconsistent, incomplete, and delayed actions have seriously harmed their reputation and done a disservice to the field of Alzheimer's research."

In a February 13, 2025 book review of Charles Piller's Doctored: Fraud, Arrogance, and Tragedy in the Quest to Cure Alzheimer's, Carl Elliott wrote that "shocking was that some of Lesné's work had come from the lab of Karen Ashe, one of the most acclaimed neuroscientists in the field", noting that the University of Minnesota had the "dubious distinction of producing two of the five most highly cited scientific papers ever to be retracted" according to Retraction Watch.