Behavioural electrophysiological and transcriptomic studies in mice show that psychedelic drugs reopen the social reward learning critical period and suggest that this involves reorganization of the extracellular matrix.
I’m not quite sure I understand what “social reward learning period” means exactly after reading through that paper. Can anyone help explain that in more concrete terms?
In the paper, they state that the 'social reward learning period' is a critical period that they described in their previous paper:
Recently, we have discovered a novel critical period for social reward learning and shown that the empathogenic psychedelic MDMA is able to reopen this critical period[11].
Their previous paper that they cite is the following:
Nardou, Romain, et al. "Oxytocin-dependent reopening of a social reward learning critical period with MDMA." Nature 569.7754 (2019): 116-120. (Scihub)
Here they are more specific about what they mean with a 'critical period':
A critical period is a developmental epoch during which the nervous system is expressly sensitive to specific environmental stimuli that are required for proper circuit organization and learning. Mechanistic characterization of critical periods has revealed an important role for exuberant brain plasticity during early development, and for constraints that are imposed on these mechanisms as the brain matures
And they point out that the term 'social reward learning' is described in the following paper:
Dölen, Gül, et al. "Social reward requires coordinated activity of nucleus accumbens oxytocin and serotonin." Nature 501.7466 (2013): 179-184. (Scihub)
From this paper, the difinition is:
Growing evidence suggests that social interaction itself can act as a natural reward
So, putting it all together:
A social interaction can in itself produce feeling of reward. The ability to experience social interaction as a reward is not 'innate', but rather an acquired ability that requires the brain to undergo certain plastic transformations. There is a period during the early development of an animal in which the region of the brain that controls the social reward pathway is highly plastic and responsive to stimuli. This period is considered a critical period, because it is during this stage that the plastic brain can develop a topology that allows the animal to feel more or less strongly rewarded by social interactions. After the critical period of development has passed, this brain region is no longer very plastic, and so the ability of the animal to experience social interactions as a reward cannot easily be changed over time.
In this study, they show that it is possible to move the brain back towards the plastic state that is present during the critical development period, potentially allowing the mature animal to develop or increase its capacity to experience social interactions as a reward.
Amazing. Thank you so much for the deep research and citations.
In other words, psychedelics seems to have a pro social effect on the mice? That’s very interesting. Especially in the world when we are increasingly trained to be anti-social.
In other words, psychedelics seems to have a pro social effect on the mice?
The psychedelic appears to bring the brain regions that are involved in pro-social effects into a more flexible state. But they do not guarantee a pro-social effect.
If you provide the right stimulus during the time that the brain is flexible, this can have a pro-social effect on the mice. But in principle it is also possible to apply the "wrong" stimulus and restructure the brain into a more anti-social state.
Psychedelics are on the path of potentially becoming a very important class of medicines because they appear to have the ability to allow the brain's neural pathways to be re-wired in a relatively short period of time. Psychedelic therapies are an interesting combination of the psychiatrist and the classical psychotherapist - the idea is that the person is given a psychedelic drug, bringing the brain into a flexible state, and the therapist attempts to provide the correct stimuli during this state to strengthen certain neural pathways associated with processes such as the reward cycles.
The value of these therapies have been recognized by our ancestors for a very long time, but only recently have they begun to be taken seriously by the scientific and medical fields. Traditionally, the stimuli are provided via set and setting and guided meditations - but the scientific field has not yet gotten that far yet. Scientists and doctors work with a much higher standard than the shamans from the past when it comes to showing that things actually work. We can't just assume that the way our ancestors did it was optimal. This is becoming an active field of research, and there is still a lot to be tested....