Wednesday 12 December 2018

New neurons: astrocytes, gene therapy and the public fear of brain modification

Ever since the first cyberpunk novels of the early 1980s - and the massive increase of public awareness in the genre thanks to Hollywood - the idea of artificially-enhanced humans has been a topic of intense discussion. Either via direct augmentation of the brain or the development of a brain-computer interface (BCI), the notion of Homo superior has been associated with a dystopian near-future that owes much to Aldous Huxley's Brave New World. After reading about current research into repairing damaged areas of the brain and spinal cord, I thought it would be good to examine this darkly-tinged area.

Back in 2009 I posted about how science fiction has to some extent been confused with science fact, which coupled with the fairly appalling quality of much mainstream media coverage of science stories, has led to public fear where none is necessary and a lack of concern where there should be heaps. When it comes to anything suggestive of enhancing the mind, many people immediately fall back on pessimistic fictional examples, from Frankenstein to Star Trek's the Borg. This use of anti-scientific material in the consideration of real-world STEM is not an optimal response, to say the least.

Rather than working to augment normal humans, real research projects on the brain are usually funded on the basis that they will generate improved medical techniques for individuals with brain or spinal cord injuries. However, a combination of the fictional tropes mentioned above and the plethora of internet-disseminated conspiracy theories, usually concerning alleged secret military projects, have caused the public to concentrate on entirely the wrong aspects.

The most recent material I have read concerning cutting-edge work on the brain covers three teams' use of astrocytes to repair damaged areas. This is an alternative to converting induced pluripotent stem cells (iPSCs) to nerve cells, which has shown promise for many other types of cell. Astrocytes are amazing things, able to connect with several million synapses. Apparently Einstein's brain had far more of them than usual in the region connected with mathematical thinking. The big question would be whether this accumulation was due to nature or nurture, the latter being the high level of exercise Einstein demanded of this region of his brain.

Astrocyte research for brain and spinal cord repair has been ongoing since the 1990s, in order to discover if they can be reprogrammed as functional replacements for lost neurons without any side effects. To this end, mice have been deliberately brain-damaged and then attempts made to repair that damage via converted astrocytes. The intention is to study if stroke victims could be cured via this method, although there are hopes that eventually it may also be a solution for Parkinson's disease, Alzheimer's and even ALS (motor neurone disease). The conversion from astrocyte to neuron is courtesy of a virus that introduces the relevant DNA, although none of the research has as yet proven that the converted cells are fully functional neurons.

Therefore, it would seem we are some decades away from claiming that genetic manipulation can cure brain-impairing diseases. But geneticists must share some of the blame for giving the public the wrong impression. The hyperbole surrounding the Human Genome Project gave both public and medical workers a false sense of optimism regarding the outcome of the genome mapping. In the late 1990s, a pioneer gene therapist predicted that by 2020 virtually every disease would include gene therapy as part of the treatment. We are only just over a year short of this date, but most research is still in first phase trial - and only concern diseases that don't have a conventional cure. It turned out that the mapping was just the simplest stage of a multi-part programme to understand the complexities of which genes code for which disorders.

Meanwhile, gene expression in the form of epigenetics has inspired a large and extremely lucrative wave of pseudo-scientific quackery that belongs in the same genre as homeopathy, crystal healing and all the other New Age flim-flam that uses real scientific terminology to part the gullible from their cash. The poor standard of science education outside of schools (and in many regions, probably within them too) has led to the belief that changing your lifestyle can fix genetic defects or affect cures of serious brain-based illnesses.

Alas, although gene expression can be affected by environmental influences, we are ultimately at the mercy of what we inherited from our parents. Until the astrocyte research has been verified, or a stem cell solution found, the terrible truth is that the victims of strokes and other brain-based maladies must rely upon established medical treatments.

This isn't to say that we may in some cases be able to reduce or postpone the risk with a better lifestyle; diet and exercise (of both the body and brain) are clearly important, but they won't work miracles. We need to wait for the outcome of the current research into astrocytes and iPSCs to find out if the human brain can be repaired after devastating attacks from within or without. Somehow I doubt that Homo superior is waiting round the corner, ready to take over the world from us unenhanced humans…

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