Sex & Gene Expression - Alzheimer's Drugs - Neuroimaging Controversy - The "Soul"

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Apr 18, 2026, 7:57:40 AM (13 days ago) Apr 18

https://www.nature.com/articles/d41586-026-01227-y

Revealed: how male and female brain cells differ in gene activity

Miryam Naddaf

By analysing more than a million brain cells, researchers have uncovered widespread differences in patterns of gene activity between male and female brains.

The work, which defined sex on the basis of a person’s combination of sex chromosomes, could help to explain why the risk of developing some brain conditions — such as schizophrenia and Alzheimer’s disease — differs between males and females.

Although the differences were subtle, the team identified more than 100 genes that showed consistent variation in their expression between males and females across several brain regions. The work was published on 16 April in Science1.

“Having these gene-expression signatures provides a molecular handle to understanding the biology of how the brains of men and women might be functioning slightly differently in the context of the different hormonal environments that their bodies produce,” says Jessica Tollkuhn, a neuroscientist and molecular biologist at Cold Spring Harbor Laboratory in New York. She adds that “understanding sex differences in disease susceptibility could lead to better treatments to benefit everyone”.
Subtle differences

Previous studies2,3 have documented sex differences when it comes to a person’s risk of developing various neurological conditions. For example, schizophrenia, attention deficit hyperactivity disorder (ADHD) and Parkinson’s disease are more common in biological males — who typically have XY sex chromosomes. By contrast, Alzheimer’s disease and mood disorders such as depression and anxiety tend to be more common in females, whose sex chromosomes are usually XX.

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https://www.nytimes.com/2026/04/15/health/alzheimers-drugs-benefit-anti-amyloid.html

Analysis of Alzheimer’s Drugs Stirs Debate About Their Effectiveness

By Pam Belluck

Since the approval of new Alzheimer’s drugs in recent years, there has been a lingering question: While data indicated that they could modestly slow cognitive decline for some patients, would that effect be meaningful or too slight to make difference?

A new review of research spanning a decade, published on Wednesday, concluded that the clinical benefit of these and similar drugs is negligible. But the way the review was conducted spurred heated criticism from many Alzheimer’s experts, including some who had been skeptical of some of them.

The review, published by Cochrane, an international network of health researchers, evaluated studies that were conducted on seven monoclonal antibody drugs developed over the last two decades to target amyloids, proteins that form plaques in the brains of people who have Alzheimer’s disease.

Some Alzheimer’s experts said the conclusions were meaningless because the review swept under one umbrella drugs that had shown very dissimilar results and worked differently. The experts noted that data from the two most recent drugs studied — Leqembi and Kisunla — showed they could slow cognitive decline, which led to approval from the Food and Drug Administration and made them the only anti-amyloid drugs available to patients.

But a vast majority of the studies analyzed in the review involved four earlier drugs that had failed clinical trials or were never approved and a fifth drug that was pulled from the market.

“The problem with the review is the mix of ingredients,” said Dr. Jason Karlawish, a director of the Penn Memory Center at the University of Pennsylvania, who has been skeptical or cautious toward some of the drugs over the years. “They took some of the rotten ingredients and mixed it in with the fresh food, and the result is a stinky stew.”

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https://www.thetransmitter.org/brain-imaging/overdue-debate-unfurls-over-neuroimaging-method/

‘Overdue’ debate unfurls over neuroimaging method

By Angie Voyles Askham

When Shan Siddiqi arrived in Australia in February to speak at the 2026 Noosa Brain Workshop, he was still thinking about a paper published in Nature Neuroscience three weeks prior. The work had criticized lesion network mapping (LNM), a neuroimaging method that Siddiqi uses as the basis for much of his work.

LNM uses the location of brain lesions in various health conditions to infer information about networks of brain activity altered in those conditions. But the January paper claimed the approach produces biased results, and points to largely the same brain networks no matter the condition.

After reading the full paper, however, Siddiqi, associate professor of psychiatry at Harvard Medical School, decided the authors’ criticism was toothless—it highlighted issues that he and his colleagues were aware of, and had already developed methods to address.

Yet to his dismay, in the following days and weeks the criticism kept coming, both on social media and in news articles, including one by The Transmitter.

The issue hung over the conference, too. During a social event on the first night of the Noosa meeting, other attendees asked Siddiqi, as a leading proponent of the method, for his thoughts, and he decided he needed to address the criticism in his talk the following day.

The next afternoon, he told the audience of senior neuroimaging researchers that he took the challenge raised in the paper seriously, and said it had caused him and his co-author Michael D. Fox to reanalyze their data in collaboration with neuroimaging statisticians. He then presented the two competing hypotheses to the audience—LNM findings are disease specific versus LNM is mathematically flawed—and explained how he and Fox tested both with real data. The results seemed to validate LNM, Siddiqi said, leading him to conclude that the critique rested on incorrect assumptions about how the method is implemented.

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https://aeon.co/essays/you-know-what-consciousness-is-you-live-in-soul-land

The invention of the soul

Nicholas Humphrey

In his novel Penguin Island (1908), Anatole France spins a wonderful tale about a blind old monk who sets off from Brittany on a mission to the Hebrides and lands on an island inhabited only by penguins. Though the birds speak a strange language, he assumes they must be human beings. So he proceeds to baptise them.

When the news of this reaches heaven, it causes a major stir. God himself is embarrassed. He gathers an assembly of clerics and doctors, and asks them for an opinion on the delicate question of whether the birds must now be given souls. It is a matter of more than theoretical importance. ‘The Christian state,’ St Cornelius points out, ‘is not without serious inconveniences for a penguin … The habits of birds are, in many points, contrary to the commandments of the Church …’ After lengthy discussion, they settle on a compromise. The baptised penguins are indeed to be granted souls – but, on St Catherine’s recommendation, their souls are to be of small size.

For the penguins, souls were an unexpected bonus. As René Descartes, the philosopher-scientist of the 17th century, had explained, nonhuman animals in general, in a state of nature, are mere soulless machines. Here’s a sketch of a Cartesian penguin, without even a smidgen of a soul.

Descartes believed that humans too are machines of a kind. But he held that, with humans, thankfully, God has arranged the addition of a soul as standard practice. Early in infancy, the material substance of the human brain is put into communication via the pineal gland with the separate substance of the mind: res extensa (extended stuff) is joined by res cogitans (thinking stuff). The consciousness that results lays the foundation for the soul.

https://www.nytimes.com/2026/04/12/health/edna-foa-dead.html

Edna Foa, Who Pioneered Exposure Therapy to Treat PTSD, Dies at 88

By Ellen Barry

Edna Foa, an Israeli American psychologist who pressed her field — and her patients — to more directly confront fear and anxiety, revolutionizing the treatment of post-traumatic stress disorder, died on March 24 at a hospital in Philadelphia. She was 88.

Her death, from complications of pneumonia, was confirmed by her daughter Yael Foa.

Dr. Foa completed her training in the late 1960s, when clinicians tended to treat people with severe anxiety disorders cautiously and gradually. One of her first patients, a woman with an intense fear of objects related to death, had been prescribed a course of “systematic desensitization.”

Dr. Foa was instructed to visit her every day carrying a small stone from a cemetery, bringing the stone a little closer each time until at long last the patient would be able to hold it.

“We started to feel that she will never get better at that rate,” Dr. Foa recalled in a 2018 podcast interview.

Dr. Foa decided to move faster, driving the patient to a funeral home and bringing her inside so that the woman was forced to deal with her distress. Avoiding those feelings, Dr. Foa posited, was actually holding the patient back.

This theory culminated, about a decade later, in Dr. Foa’s landmark innovation.

In the 1980s, she developed prolonged exposure therapy, a structured protocol of eight to 12 90-minute sessions in which the patient recounts a traumatic event in the present tense, lingering on the most vivid and upsetting elements. Then the patient undertakes real life exposure to reminders of the event.

These sessions could be uncomfortable, Dr. Foa acknowledged. But they served to ease the patient’s sensitivity and correct flawed thinking, demonstrating that there was no harm in confronting the feared object, place or event. Over the years that followed, a series of studies supported the approach’s effectiveness.