Szechuan peppers neuroscience

Nature Neuroscience 11, 772 – 779 (2008)
Published online: 22 June 2008 | doi:10.1038/nn.2143

Pungent agents from Szechuan peppers excite sensory neurons by inhibiting two-pore potassium channels

Diana M Bautista1,2,3,4, Yaron M Sigal1,2,4, Aaron D Milstein2, Jennifer L Garrison2,3, Julie A Zorn2, Pamela R Tsuruda1,2,3, Roger A Nicoll1,2 & David Julius1,2

Abstract

In traditional folk medicine, Xanthoxylum plants are referred to as ‘toothache trees’ because their anesthetic or counter-irritant properties render them useful in the treatment of pain. Psychophysical studies have identified hydroxy-alpha-sanshool as the compound most responsible for the unique tingling and buzzing sensations produced by Szechuan peppercorns or other Xanthoxylum preparations. Although it is generally agreed that sanshool elicits its effects by activating somatosensory neurons, the underlying cellular and molecular mechanisms remain a matter of debate. Here we show that hydroxy-alpha-sanshool excites two types of sensory neurons, including small-diameter unmyelinated cells that respond to capsaicin (but not mustard oil) as well as large-diameter myelinated neurons that express the neurotrophin receptor TrkC. We found that hydroxy-alpha-sanshool excites neurons through a unique mechanism involving inhibition of pH- and anesthetic-sensitive two-pore potassium channels (KCNK3, KCNK9 and KCNK18), providing a framework for understanding the unique and complex psychophysical sensations associated with the Szechuan pepper experience.

induction of out of body experiences using virual reality

By SANDRA BLAKESLEE NY Times Published: August 24, 2007

Using virtual-reality goggles, a camera and a stick, scientists have induced out-of-body experiences — the sensation of drifting outside of ne’s own body — in ordinary, healthy people, according to studies being published today in the journal Science. When people gazed at an illusory image of themselves through the goggles and were prodded in just the right way with the stick, they felt as if they had left their bodies.

The out-of-body experiments were conducted by two research groups using slightly different methods intended to expand the so-called rubber hand illusion.

In Switzerland, Dr. Olaf Blanke, a neuroscientist at the École Polytechnique Fédérale in Lausanne, asked people to don virtual-reality goggles while standing in an empty room. A camera projected an image of each person taken from the back and displayed that image as if it were six feet in front of the subject, who thus saw an illusory image of himself. Then Dr. Blanke stroked each person’s back for one minute with a stick while simultaneously projecting the image of the stick onto the illusory body. When the strokes were synchronous, people reported the sensation of being momentarily within the illusory body. When the strokes were not synchronous, the illusion did not occur.

In another variation, Dr. Blanke projected a “rubber body” — a cheap mannequin bought on eBay and dressed in the same clothes as the subject — into the virtual-reality goggles. With synchronous strokes of the stick, people’s sense of self drifted into the mannequin.

A separate set of experiments was carried out by Henrik Ehrsson, an assistant professor of neuroscience at the Karolinska Institute in Stockholm.

Anticipation of monetary gain but not loss in healthy older adults

Something to remind ourselves when we get older …

Nature Neuroscience – 10, 787 – 791 (2007)

Published online: 29 April 2007

doi:10.1038/nn1894

abstract below:

Although global declines in structure have been documented in the aging human brain, little is known about the functional integrity of the striatum and prefrontal cortex in older adults during incentive processing. We used event-related functional magnetic resonance imaging to determine whether younger and older adults differed in both self-reported and neural responsiveness to anticipated monetary gains and losses. The present study provides evidence for intact striatal and insular activation during gain anticipation with age, but shows a relative reduction in activation during loss anticipation. These findings suggest that there is an asymmetry in the processing of gains and losses in older adults that may have implications for decision-making.

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(half a) Mouse brain simulated on computer

From the BBC. What this article does not make clear is the amount of idealization involved. Neuronal interactions are so complicated at the chemical level, and there might be aspects which are not understood yet.

US researchers have simulated half a virtual mouse brain on a supercomputer. The scientists ran a "cortical simulator" that was as big and as complex as half of a mouse brain on the BlueGene L supercomputer. In other smaller simulations the researchers say they have seen characteristics of thought patterns observed in real mouse brains. Now the team is tuning the simulation to make it run faster and to make it more like a real mouse brain.

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Orangutans play video games

At 4, Bernas is not the computer wizard his mom is, but he is learning. Just the other day he used his lips and feet to play a game on the touch-screen monitor as his mom, Madu, swung from vines and climbed trees. The two Sumatran orangutans are part of new Zoo Atlanta research that uses computer games to study the cognitive skills of the primates.

The best part? Visitors to the US zoo get to watch their every computer move. The orangutans play the games on a touch screen built into a tree-like structure in the habitat to blend in with their environment. Visitors watch from a monitor in front of the orangutan exhibit.

Read

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Is a chimp a person? Court to decide

Chimps are intelligent creatures. They pass the mirror test and so possess self-consciousness. I would argue there is a significant difference in moral status between animals with self-consciousness, and animals without. This does not mean that we can do whatever we want to those without, but the interests of those animals with self-consciousness are more weighty.

Court to rule if chimp has human rights Sunday April 1, 2007 The Observer

He recognises himself in the mirror, plays hide-and-seek and breaks into fits of giggles when tickled. He is also our closest evolutionary cousin.

A group of world leading primatologists argue that this is proof enough that Hiasl, a 26-year-old chimpanzee, deserves to be treated like a human. In a test case in Austria, campaigners are seeking to ditch the ‘species barrier’ and have taken Hiasl’s case to court. If Hiasl is granted human status – and the rights that go with it – it will signal a victory for other primate species and unleash a wave of similar cases.

Hiasl’s story began in 1982 when, as a baby, he was taken from Sierra Leone and smuggled into Austria in a crate with seven other chimps destined for a vivisection laboratory east of Vienna. But customs officers seized the crate and Hiasl was sent to an animal sanctuary. Now the sanctuary faces bankruptcy and Hiasl could be sent to the Baxter vivisection laboratory after all. Seeking to save Hiasl, who likes painting, kissing visitors and watching wildlife programmes, an Austrian businessman has donated £3,400 towards his upkeep.

However, unless Hiasl has a legal guardian who can manage the money it will go to the receivers. As only humans have a right to legal guardians, his campaigners say it is necessary for Hiasl’s survival to prove that he is one of us. Primatologists and experts – from the world’s most famous primate campaigner, Jane Goodall, to Professor Volker Sommer, a renowned wild chimp expert at University College London – will give evidence in the case, which is due to come to court in Vienna within the next few months.

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Utilitarians have brain damage

Not really. Rather, some people with damage to the prefrontal cortex seem more likely to make impartial utilitarian moral judgments that many normal people find difficult to accept, like killing a single person in order to save a larger number of people. This is very interesting research.

"Damage to the prefrontal cortex increases utilitarian moral judgements"

Michael Koenigs et. el. (including Damasion)

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Reading Hidden Intentions in the Human Brain

This is the paper mentioned in an earlier post:

Current Biology, Vol 17, 323-328, 20 February 2007
Haynes JD, Sakai K, Rees G, Gilbert S, Frith C, Passingham RE.

Yahoo report: By MARIA CHENG, AP Medical Writer

BERLIN – At a laboratory in Germany, volunteers slide into a donut-shaped MRI machine and perform simple tasks, such as deciding whether to add or subtract two numbers, or choosing which of two buttons to press. They have no inkling that scientists in the next room are trying to read their minds — using a brain scan to figure out their intention before it is turned into action.

In the past, scientists had been able to detect decisions about making physical movements before those movements appeared. But researchers at Berlin’s Bernstein Center for Computational Neuroscience claim they have now, for the first time, identified people’s decisions about how they would later do a high-level mental activity — in this case, adding versus subtracting.

The research, which began in July 2005, has been of limited scope: only 21 people have been tested so far. And the 71 percent accuracy rate is only about 20 percent more successful than random selection.

In one study, participants were told to decide whether to add or subtract two numbers a few seconds before the numbers were flashed on a screen. In the interim, a computer captured images of their brain waves to predict the subject’s decision — with one pattern suggesting addition, and another subtraction.

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