Pleasure or pain? He maps the neural circuits that decide
quantamagazine.org
quantamagazine.org
> We are also super excited about how the brain controls the transition from acute to chronic pain. We use our pain scale to measure the pain level in a mouse and then take a snapshot of the mouse’s brain activity using functional magnetic resonance imaging. We image the animals every day to find brain activity patterns that underlie the transition from acute to chronic pain. Once we find them, we can try to change them to alter the course of chronic pain. We’re interested in the emotional as well as sensory components of this pain.
> When we activated neurons through the skin on the mice’s backs, the animals behaved as if they were being stroked there. That launched the whole project. We did a lot more behavioral tests and traced the pathway for social touch from the skin to the spinal cord to the reward centers in the brain.
> What if we could turn on these neurons with a skin cream to improve mental health — say, to offset the harm caused by social isolation or to treat anxiety or depression? When I gave a talk about this in December, the psychiatrists and neuropharmacologists in the audience were very enthusiastic about the therapeutic potential.
> We’re also interested in them because mole rats do not feel some forms of pain. For example, they show no pain response to the molecule capsaicin, the active ingredient in hot peppers, which is quite painful to most mammals. They have receptors in their skin that respond to capsaicin, so I hypothesize that the animals have brain pathways that shut down the pain. If we can find and tap into those signals, we might find a new way to block pain.
They are taking a multidisciplinary approach to researching an understudied field, and it's fascinating. Why is no-one else seeing that?
I know there are some serious mental health ailments that require pharmaceutical treatment, but using Soma-like chemicals to make humans simply feel okay with what's bothering them sounds to me like a surefire way to destroy a society. Things like antidepressants, weed, porn and social media have are already moved us in that direction, but seeing this sort of stuff as an achievement just sounds dystopian to me.
These drugs are not to be taken lightly, but I don't like pain, I don't like people being in pain, so if there are ways of making people feel better, I am all for it. And every new treatment we find is a new option, one that we may be able to use as a substitute for something with worse side effects, like opium.
The quoted example of treating depression due to social isolation is a perfect example. People already feel depressed because they replace true human connection with parasocial and digital ones, and I think it would be absolutely destructive to just slap a feel-good-patch on every kid's arm rather than us recognizing as a collective that something is going the wrong way with our society.
Is the argument here that making pain medication more accessible inevitably leads to misuse? I suppose Tylenol would be problematic then.
Perhaps it’s a hypothetical high potency that is the concern? Then fentanyl is the concern here.
But what if fentanyl but no side effects? Is that world worse or better?
I know someone on the ethics board at a university and the experiments here aren’t so terrible
> First, we verified that a stimulus deemed innocuous, like the touch of a soft makeup brush, activated touch neurons in the animal’s skin, and that a needle pricking the skin activated pain neurons. Then we recorded the animal’s response movements to each stimulus.
Human experiments on pain usually involve sticking a hand in a bucket of ice water. People taking their daily diabetes medication, prick skin multiple times a day without complaint, though it might be unpleasant.
But I’ll agree there’s a lack of sensitivity to the needless suffering of animals inflicted by humans. e.g., labs and factory farms have a lot to answer for. Though if we wanted to end suffering of all beings, we’d probably just want to terminate life completely such that a living being can never contrive to hurt another.. or somehow reengineer the biosphere to eliminate r-selection, and predation, an even more absurd proposition.
Escapades and adventures. That's perfect I wish schools would encourage more of that.
> In my final year as a postdoc, I genetically engineered mice to have gentle touch neurons that responded to blue light. My plan was to stimulate the neurons with blue light and see what the mice did.
> When I started my own lab in 2018, we were ready to start those experiments. I still remember the day the students came into my office to show me what they had found. It was like this eureka moment. When we activated neurons through the skin on the mice’s backs, the animals behaved as if they were being stroked there. That launched the whole project. We did a lot more behavioral tests and traced the pathway for social touch from the skin to the spinal cord to the reward centers in the brain.
document.querySelectorAll("img").forEach(x => x.remove())