Fast-Changing Dangerous Drugs - Tree-climbing Mice - Imagining Vision

[Breedlove, S]

https://www.nytimes.com/interactive/2026/04/08/health/illegal-labs-potent-drugs.html

The Fast-Changing Chemistry of New, Dangerous Drugs

By Jonathan Corum and Matt Richtel

Illicit labs are creating new synthetic drugs at breakneck speed. Dangerous, untested compounds are reaching users long before health agencies know they exist. Older drugs are regularly modified to create novel threats. Ecstasy is a prime example.

The party drug MDMA has been illegal since 1985. Its molecular structure can be drawn like this:

But what if you could add one atom to this molecule to change both the experience of taking the drug and its legal status?

You can. A single oxygen atom changes the molecule to methylone, which provides an Ecstasy-like euphoria.

The discovery of what this simple change could do has had a profound consequence. When methylone reached the U.S. market in 2010 the drug could be sold legally in corner stores and smoke shops as “bath salts.”

But methylone wasn’t the end of the story. Illicit chemists now use methylone’s structure as a template for modern-day alchemy. New drug laws push them to invent new variants, which emerge in the illicit drug market with untested potencies and effects — a vicious cycle that has been impossible to contain.

These chemists are located in unregulated labs around the globe, from big enterprises in China and India that produce drugs and their precursor compounds in huge volumes, to single-person and small domestic operations that cut and package drugs for retail sale. Some of the most-used drugs, such as fentanyl, are mixed in Mexico and exported north.

    © 2026 The New York Times Company


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https://www.thetransmitter.org/evolution/arboreal-deer-mice-reveal-neural-roots-of-dexterity/

Arboreal deer mice reveal neural roots of dexterity

By Siddhant Pusdekar

Deer mice, common across North America, come in two varieties: One lives in prairies, whereas the other inhabits forests. The life of the forest mouse requires greater dexterity—a skill it possesses thanks to its higher number of corticospinal tract axons, according to a January preprint.

The existence of “genetically tractable subspecies of deer mice with different behavioral niches” made the discovery possible, says Eiman Azim, associate professor of molecular neurobiology at the Salk Institute for Biological Studies, who wasn’t involved in the study. It enabled the researchers to link genetically driven changes in corticospinal abundance and morphology to dexterity.

The new work reveals one way dexterous skill may emerge, while also suggesting neuroscience should investigate “behaviors that evolved for the natural niches” to discover fresh insights, says Ariel Levine, a senior investigator at the U.S. National Institute of Neurological Disorders and Stroke, who wasn’t involved in the study.

Dexterity in primates coevolved with direct connections between layer 5 cortical neurons and motor neurons in the spinal cord, Levine says. In rodents, cats and less dexterous monkeys, however, corticospinal neurons connect to motor neurons via interneurons. 

Direct cortical-motor neuron connections exist in juvenile mice, but they are pruned during development, a 2017 paper showed. Artificially stopping the pruning process created adult lab mice with greater skill at gathering food pellets. 
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https://www.sciencenews.org/article/seeing-imagining-activate-brain-cells

Seeing and imagining activate some of the same brain cells

By Diana Kwon

The ability to conjure pictures in the mind’s eye enables us to remember the past and imagine the future. It also allows us to plan, navigate and create works of art. In a study published April 9 in Science, researchers report that imagining an object reactivates some of the same neurons involved in seeing it in the first place, providing new insight into how mental imagery is produced in the brain.

Previous research had hinted that the neurons involved in perceiving and imagining images overlapped. These studies used various methods, such as asking participants to view and then imagine pictures while lying in a functional MRI scanner, to show that the same brain regions were involved in these processes. But whether the same individual neurons were involved remained an open question, says Ueli Rutishauser, a neuroscientist at Cedars-Sinai Medical Center in Los Angeles.

Because measuring neuronal activity requires electrodes in the brain, Rutishauser and colleagues studied 16 adults with epilepsy who had already had electrodes temporarily implanted into their brains to identify the origin of their seizures. Participants viewed hundreds of images from five categories — faces, text, plants, animals and everyday objects — while researchers recorded activity from over 700 neurons in the ventral temporal cortex, a region involved in representing visual objects. Of those, about 450 selectively responded to individual categories. Machine learning then revealed that 80 percent of those category-responsive neurons were selective to specific visual features within the images.

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