Why LSD Trips Last So Long and Make Everything Seem So Meaningful
Two recent studies reveal the effects of LSD on the brain.
While LSD has been around since 1938, when it was synthesized by the Swiss scientist Albert Hoffman, how exactly it works has continued to be a mystery. As LSD research has picked up, two new studies provide insight on what happens to the brain on LSD, the common name for Lysergic acid diethylamide. One group of scientists figured out the structural changes LSD makes in the brain while the other looks at how LSD makes people create meaning.
Research published in Cell zeroed in at what LSD looks like when attached to a brain receptor.
The team led by Bryan L. Roth, MD, PhD from the UNC School of Medicine used x-ray crystallography to “freeze” and capture images of LSD attached to a serotonin receptor (a protein that senses serotonin, a chemical messenger). The researchers found that the LSD molecule is essentially locked on to that part of the brain as the receptor folds over it like a lid. This explains why the effects of an LSD trip last so long, lingering for 12 hours or more even if LSD molecules are known to clear from the blood in a few hours.
"We think this lid is likely why the effects of LSD can last so long," said Roth, "LSD takes a long time to get onto the receptor, and then once it's on, it doesn't come off. And the reason is this lid."
The answers his team was able to get clears up the question Roth held from his youth.
“When I was younger, and The Grateful Dead was still around, I would occasionally go to Grateful Dead concerts. A lot of people took LSD and similar drugs during concerts, and it would be interesting to be in the parking lot hearing people wondering when their LSD experience was going to end," said Roth. "A lot of people who take the drug are not aware of just how long it lasts."
A molecule of LSD bound to a larger serotonin receptor. The 'lid' that keeps LSD bound so long is the orange bar running through the center. Credit: Lab of Bryan Roth, UNC School of Medicine
The trip ends when LSD molecules get off their receptors, while brain cells eventually pull the receptors into the cell, where they (along with the LSD) get degraded or recycled.
The scientists think their research will help in the development of new treatments, especially considering the recent popularity of LSD microdosing to combat depression or increase creativity.
Another study, this one published in Current Biology, looked at how LSD affects perception. They found specific neurochemicals and receptors in the brain responsible for “loosening” the boundaries of the self and creating a sense of meaning while on an LSD trip. What they were after is to understand why people on LSD paid so much attention to details or objects which normally would not elicit such a focus.
"Our results increase our understanding of how personal relevance attribution is enabled in the brain," said Katrin Preller of the Zürich University Hospital for Psychiatry. "[We now know] which receptors, neurotransmitters, and brain regions are involved when we perceive our environment as meaningful and relevant."
In particular, the researchers studied a group of people on LSD versus a group on placebos, having them rank the meaning of specific songs or musical compositions. It turned out that songs which previously didn’t mean much became very significant to the subjects on LSD. Doing this, while scanning the brains of the participants, allowed the scientists to identify the specific receptors involved in creating that meaningfulness.
"By combining functional brain imaging and detailed behavioral assessments using a specific experimental paradigm to investigate personal relevance or meaning of music pieces, we were able to elucidate the neurobiological correlates of personal relevance processing in the brain," explained Preller. "We found that personal meaning attribution and its modulation by LSD is mediated by the 5-HT2A receptors and cortical midline structures that are also crucially involved in enabling the experience of a sense of self."
Further studies of the identified 5-HT2A receptors may lead to understanding how “excessive stimulation” of these receptors can be responsible for the peculiar feelings and sensations of people on a psychedelic trip. The goal is to develop new treatments for psychiatric illnesses.
Cover photo: Artistic representation of the chemical structure of LSD -- highlighted in yellow -- interlocking into a red-orange ribbon diagram of the serotonin receptor. Credit: Annie Spikes
What would happen if you tripled the US population? Join Matthew Yglesias and Charles Duhigg at 1pm ET on Monday, September 28.
Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
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