Posts Tagged ‘Catherine Offord’


Preliminary findings from a clinical trial of heavy drinkers suggest that the drug can weaken certain memories tied to the reward of imbibing, although the mechanisms aren’t fully clear.

by CATHERINE OFFORD

he anesthetic drug ketamine could be used to rewire heavy drinkers’ memories and help them cut down on alcohol consumption, according to a study published yesterday (November 26) in Nature Communications. In a clinical trial of people who reported consuming around 590 grams of alcohol—equivalent to nearly two cases of beer—per week on average, researchers found that a procedure that involved administering the drug while people were thinking about drinking durably reduced consumption.

While it’s not clear how the method works at a neurological level, the study represents “a really exciting development,” Amy Milton, a behavioral neuroscientist at the University of Cambridge who was not involved in the work, tells STAT. She adds that the findings mark “the first time it’s been shown in a clinical population that this can be effective.”

The study was designed to manipulate the brain’s retrieval and stabilization of memories—in this case, those linking the sight and thoughts of alcohol to the reward of drinking it, study coauthor Ravi Das, a psychopharmacologist at University College London, tells Science News. “We’re trying to break down those memories to stop that process from happening.”

To do that, the team asked 30 of the participants to look at a glass of beer, followed by a sequence of images of alcoholic and non-alcoholic drinks. On the first day of tests, the session ended with participants being invited to drink the beer. On the second day, after viewing the beer and images, the screen cut off, and instead of drinking the beer, participants were given a shot of ketamine.

Among various functions, ketamine blocks NMDA receptors—key proteins in the brain’s reward pathways—so the researchers hypothesized that administering the drug during memory retrieval would help weaken participants’ associations between the sight or contemplation of alcohol and the reward of drinking it. Their results somewhat support that hypothesis. Nine months following the several-day trial, the volunteers reported cutting their drinking back by half.

“To actually get changes in [participants’] behavior when they go home and they’re not in the lab is a big deal,” Mary Torregrossa, a neuroscientist at the University of Pittsburgh who was not involved in the work, tells Science. But she notes that it’s not clear whether it was the ketamine or some other part of the procedure that led to the effect.

Another 60 participants, split into two control groups, received slightly different procedures that involved either beer or ketamine and still showed, on average, a 35 percent decrease in alcohol consumption after nine months. The participants themselves were recruited to the study through online ads—meaning that the researchers may have selected for people already interested in reducing consumption.

Whatever the mechanisms behind the effect, the results so far suggest the method is worth investigating, David Epstein, an addiction researcher at the National Institute on Drug Abuse, tells Science News. “If a seemingly small one-time experience in a lab produces any effects that are detectable later in real life, the data are probably pointing toward something important.”

Catherine Offord is an associate editor at The Scientist. Email her at cofford@the-scientist.com.

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The 12-million-year-old bones of a previously unknown species named Danuvius guggenmosi challenge the prevailing view about when and where our ancestors first started walking upright.

by CATHERINE OFFORD

Researchers in Germany have discovered the fossilized bones of a previously unknown species of ape that appeared to walk upright, according to a study published yesterday (November 6) in Nature. The bones, which the team dated to nearly 12 million years ago, suggest that bipedalism might have evolved in a common ancestor of humans and other great apes living in Europe, and not in more-recent human ancestors in Africa as many researchers had assumed.

The finding “changes the why, when and where of evolution of bipedality dramatically,” study coauthor Madelaine Böhme, a paleobiologist at the University of Tübingen in Germany, tells Reuters.

There are many theories about the evolution of bipedalism, but many assumed that upright walking appeared in our ancestors about 6 million to 8 million years ago—possibly as an adaptation to a reduction in forest cover occurring in East Africa around the same time.

See “Exploding Stars Probably Didn’t Spur Hominins to Walk Upright”
The new set of bones, unearthed from a clay pit in Bavaria between 2015 and 2018, are around 11.62 million years old and belong to several baboon-size apes, members of a species researchers have named Danuvius guggenmosi. The limbs show an unusual combination of anatomical features indicative of an ability to move both by swinging through trees and by walking upright.

“It was astonishing for us to realise during the process of research how similar certain bones were to humans, as opposed to great apes,” Böhme says in a statement, The Guardian reports.

“Together, the mosaic features of D. guggenmosi arguably provide the best model yet of what a common ancestor of humans and African apes might have looked like,” writes Tracy Kivell, a paleoanthropologist at the University of Kent who was not involved in the work, in an accompanying commentary in Nature. “It offers something for everyone: the forelimbs suited to life in the trees that all living apes, including humans, still have, and lower limbs suited to extended postures like those used by orangutans during bipedalism in the trees.”

The fossils could help researchers study hominid evolution more generally, the authors write in their paper. “With a broad thorax, long lumbar spine and extended hips and knees, as in bipeds, and elongated and fully extended forelimbs, as in all apes (hominoids), Danuvius combines the adaptations of bipeds and suspensory apes, and provides a model for the common ancestor of great apes and humans.”

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