Research into psychedelic medicines is progressing along two lines. Clinical research is demonstrating how effective these medicines are in treating conditions like depression, PTSD, substance abuse disorders, and others. Meanwhile, basic biomedical research is showing us how these miracle drugs work on structures within the brain. Researchers are able to combine information gained from both lines of research to better understand psychedelic medicines and discover more potential uses. In this regard, a study out of Johns Hopkins shows that psychedelic medicines reopen critical period learning windows in animal studies.
Critical Period Learning Windows
There are important times for learning in the development of humans as well as members of the animal kingdom. These critical periods affect things like learning language, social bonding, and even hearing and speech. A commonly used simple example is the imprinting of young birds. This is where a newly hatched bird imprints on its mother. This imprinting requires that the mother is around and that the baby bird sees her within an hour or two of its hatching. If she is not available for a day or so the baby bird does not imprint or bond to its mother. An example that applies to humans is how a young child can pick up a new language much more quickly and completely than an adult can.
Brain Plasticity and Critical Learning
In the human example of learning a language the issue is not that the adult is busy with other tasks while the child has nothing else to do. Rather it has to do with how receptive the brain is to taking in new information. During specific periods in child development the brain is more plastic or receptive to new info. This is before connections between brain cells or neurons stabilize and solidify. Researchers have discovered that periods of plasticity end with the maturation of synapses which inhibit a specific neurotransmitter, GABA. In addition to critical learning periods early in life there are so-called sensitive periods in which a person (or other animal) is more receptive than usual to outside influence which can affect learning or will affect behavior. The recent research regarding psychedelic medicine sheds new light on how critical learning windows can be reopened later in life.
Why Are Critical Learning Windows Important in Later Life?
For the treatment of stroke patients, children with a lazy eye, or deaf people the ability to regain the learning capacity of an early-life critical learning window may make the difference between successful recovery or treatment and failure. Doctors at Johns Hopkins did a series of simple experiments with mice using MDMA, psilocybin, ketamine, ibogaine, and LSD. They introduced adult mice that had been raised in isolation to a social environment. Normally an adult mouse does not learn social skills when this happens. But when given one of the psychedelic medicines the adult mice learned social skills just like they would have when young. The only differences among the various psychedelic medicines were the lengths of time the learning window stayed open. For ketamine the learning window was open for about 48 hours, for psilocybin and MDMA it was about two weeks, for LSD three weeks, and for ibogaine it was about four weeks.
How Critical Learning Period Information May Help Psychedelic Treatments
An interesting insight is that people who have taken any of these psychedelic medicines report the effects lasting similar lengths of time to the learning windows seen in mice. This is true for each of the psychedelic medicines. The assumption is that the same effects are operating in humans who are given psychedelic medicines as happen in the simple mouse experiment. The Johns Hopkins researchers note that when people receive psychedelic medicines as adjunctive therapy for depression, PTSD, or substance abuse disorders the sessions last a few hours out to perhaps a day or so. It may be wise to consider the length of time that a critical learning period window is reopened in deciding how long to treat with a specific medicine, how long to continue cognitive therapy (coaching), and when to send the patient back to their normal, chaotic life.
Biomolecular Changes with Psychedelic Medicines
In their mouse study researchers looked for what happened on a molecular level to cause learning windows to reopen. They discovered that these medicines activate RNA (ribonucleic acid) which in turn produces proteins that are involved in maintaining or repairing the matrix of cells in the brain associated with learning social behaviors.
What this research will do is help clinicians fine tune their treatments with psychedelic medicines and even extend treatments into realms like post-stroke therapy or helping kids with a lazy eye learn how to use both eyes to see and process information.