Remember the article about Dr Lodge and his rats treated with fetal rat brain cells? This is the next step towards eventual human trials (though they are still a ways out - at least they are working towards them.)
Short version:
“These interneuron transplants integrate within the existing circuitry, reduce hippocampal hyperactivity and normalize aberrant dopamine neuron activity. Further, interneuron transplants alleviate behaviors that model negative and cognitive symptoms, including deficits in social interaction and cognitive inflexibility. Interestingly, PV- and SST-enriched transplants produced differential effects on behavior, with PV-enriched populations effectively normalizing all the behaviors examined. These data suggest that the stem cell-derived interneuron transplants may represent a novel therapeutic strategy for schizophrenia.”
Long version:
They did the interneuron transplants in adolescent mice, and they tested them 30 days later and found that the treatment was effective. They will later have to determine how long lasting the effects are; do the effects last through the mice’s lifetime, and can the transplants be carried out in later life. In humans, it is thought that most of the aberrant brain development in sz has already occured by adolescence, so the fact that it worked in adolescent mice is probably a good sign.
I think they are getting closer to the biological causes. Causes, multiple, not singular. Part of the difficulty is that it’s not the same for everyone. One thing that seems to be a recent development is the observation that different genes express at different times in life, and they may be over or under active. Since that influences brain development from that point on, probably it will be harder to treat cases where things went wrong earlier in life, causing a cascade of effects. But I do think there’s hope even in early onset or in longstanding cases because of some of the early work in this area that indicates making corrections to genes (in mice) can resolve symptoms even in adulthood. It also appears that (in mice) stem cells can restart critical periods of development. This may be possible for humans as well.
The trouble is, there’s not a whole lot of researchers working in this area, just a handful. And it’s going to take a long time. The technology is getting there, but the research takes a long time. Plus there’s a lot of risk in injecting a human who does not have a terminal illness in the brain with anything, particularly something that’s supposed to grow and integrate into the brain. I think that the progress made with Parkinson’s, in which they are also investigating stem cell and genetic treatments, will help. They have treated a handful of people with sz with DBS implants, so it’s not unheard of that they would be able to find both researchers and subjects willing to take this risk.
Technology now is changing so fast that it’s probably pointless to make predictions more than 25 years out, but because of the slow pace of translation from “lab to bedside” it’s probably somewhere in that range. I do think it will be this generation of scientists to try it though, not the next.
Dr Lodge has also published an abstract of a paper that will be released next year, I’ll be looking for that for an idea of what and when the next steps are.
Deep Brain Stimulation. There have been positive results, but the technology they’re using only stimulates 1 or 2 areas. New materials might allow for stimulation of more areas. But right now, it’s a thru the skull operation, so it is not without risk.
I think it is first necessary to confirm what goes wrong in the brain in schizophrenia.
Once it becomes clear how the brain is affected, and not just regarding positive symptoms,
it will be easier to develop treatments that target the relevant regions of the brain.