Psychedelic drugs became widely popular in the 1960s counterculture. Similarities between reports of LSD users and psychosis led researchers to consider that serotonin might help mediate the experience. Scientists now are quite certain that the subjective and behavioral effects of psychedelics are produced by the arousal of certain serotonin receptors. Due to the classification of being a controlled substance, psychedelic researched ceased. It was not until the idea that psychedelics could be implemented into treatments of certain illnesses that research started up again.
With the advent of PET scans, researchers were able to see where psychedelic drugs acted on the brain. LSD users showed increased activation in the prefrontal cortex and the anterior cingulate cortex (ACC). This finding corresponds with expectations that the "trips" one experiences while on LSD is an increase in brain activity. A new study done by David Nutt at Imperial College London is uprooting these notions.
In his study, he gave patients either a placebo or an injection of LSD and put them under an fMRI to see what goes on in the brain during a "trip." His results should that brain activity was widely reduced. Blood flow was reduced in regions of the thalamus, the medial prefrontal cortex (mPFC), the ACC and the posterior cingulate cortex. Also, the more activity was reduced in the mPFC and ACC, the more the subjects felt the effects of LSD. The scans showed no increase anywhere in the brain. The mind expanding effect of psychedelic drugs is produced by turning the dial down on brain activity.
The ACC and parts of the mPFC inhibits the limbic system and other structures. Reduction in response of the ACC and mPFC would allow the limbic system, which processes emotion and perhaps sensory cortices, increase its role. These findings are still speculation because the tests need to be replicated in other labs and the discrepancies of the earlier PET findings need to be explained. What is most interesting in these findings is that the regions that show the most reduction are also the most heavily interconnected in the brain. This means that the brain becomes more fragmented when on psychedelic drugs, this could account for some of the dissociative aspects of acid trips.
Source:
Christof Koch. (2012.) This is Your Brain on Drugs. Scientific American Mind, May/June 2012, p.18-19.
I think this research has profound implications for our understanding of the brain, especially psychopathology. I've heard recently that those suffering from depression actually have MORE active neural connections, somewhat counterintuitive to our image of the lethargy associated with depression. Maybe the psychedelic dampening described above could help to relieve depressed patients. Could a form of LSD be on the pharmaceutical market in the future?? Only time will tell...
ReplyDeleteThis may be a bit out there but here goes . . .
ReplyDeleteSo the evolution of the human brain since ancient times has brought us deeper and deeper into the realms of scientific thinking, and directed us gradually farther from the more mystic and superstitious ways of thinking about the world. Many would argue that human brains have evolved to give us a more and more realistic awareness. Could it be though that the evolution of the brain has merely brought us to a different way of perceiving the world around us, not necessarily more realistic - just different? Perhaps ancient mythologies and scriptures portraying what we now deem to be fantastical/miraculous were actually real to ancient brains due to naturally less activity in the brain regions described above? As times have changed, human society has become more and more demanding of our brain power and the brain has evolved to keep up. So perhaps, way back in ancient times, when life was less complicated, the brain performed differently and gave people a whole different experience of reality (without LSD).
Many current, anti-depressant drugs doctors prescribe to help defeat clinical depression include re-uptake inhibitors that increase neurotransmission. LSD,on the other hand, as this article proposes, decreases activity in the brain. This alternate approach of using pyschedelics in a controlled setting is a hot topic, but I'm sure this study had to go through a grueling IRB to publish their results. Perceiving the world differently may in fact lesson depression for it gives the affected individual different ways to think about any given topic(cognitive restructuring), making neuroticism harder and harder to stand by. The jargon that corresponds to LSD usage such as 'coming up' and 'getting high' may need to be reconsidered after these findings by David Nutt
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