I read an article that annoyed me a bit. It’s a rant by John Horgan against optogenetics and why the author is vexed by breathless reports of manipulating brain functions using light (optogenetics is where you genetically modify brain cells to enable you to manipulate their behaviour – stimulating or suppressing their firing – using light. This is particularly cool because it allows much better targeted control of brain cells than using implanted electrodes or injecting drugs, the other most precise methods of controlling the activity of many cells). I love me a good rant, and here is a nicely considered article about the limits and hype over optogenetics [NB: I am not an expert in optogenetics], but this was neither good nor considered.
The first half of the article raises a complaint about the hype, which might have been legitimate if it had not misrepresented said hype. It grumbles that articles about optogenetics tout its therapeutic potential for human patients, but we don’t know enough about the mechanisms underlying mental illnesses to treat them with optogenetics. While this latter point is certainly true, it’s a straw-man: read the articles linked-to in the first half and see which ones you think are about human therapeutic potential (I’ve included the links at the bottom*). They all clearly report on animal studies, though of course make reference to the potential for helping to treat human illnesses (not necessarily using optogenetics directly, but by better understanding the brain through optogenetics). Indeed, this point was made to John on Twitter, so his article now includes a clarification at the end admitting as much, but still making some unconvincing points, which we’ll come to later.
The second part of the article addresses John’s “meta-problem” with optogenetics: he “can’t get excited about an extremely high-tech, blue-sky, biomedical ‘breakthrough’-involving complex and hence costly gene therapy and brain surgery-when tens of millions of people in this country [USA] still can’t afford decent health care.” Surely this is a problem with all medical (and, indeed, basic) research that doesn’t address the very largest problems in the health system? I agree totally that this is a massive problem, but it is entirely socio-political, not scientific. Moaning that optogenetic treatments will be expensive is like criticising NASA because only a few lucky astronauts get to go into space.**
John has been good enough to add some “examples of researchers discussing therapeutic applications” to his post. Briefly looking through these, we have a 2011 article in the Joural of Neuroscience, which uses optogenetics to study the role of a particular brain area in depression (doesn’t mention therapeutic optogenetics in abstract, only as a potential avenue for further research in the conclusion); a 2011 TED talk (the whole point of such talks is hype and speculation); this press release from the University of Oxford (which alludes to possible therapeutic use “in the more distant future” in one paragraph in a sixteen paragraph article); a 2011 article in Medical Hypotheses (a non-peer-reviewed journal whose entire point is to publish speculative articles that propose potentially fanciful hypotheses); and this article in the New York Times (I can’t argue with this – there is a fair bit on therapies for humans; John’s main gripe here, from his comments about this article, appears to be with the military funding that one of the several mentioned projects is receiving).
In the second amendment to the article – labeled “clarification” – John admits that he “overstated the degree to which coverage of optogenetics has focused on its potential as a treatment rather than research tool”, which is nice, but then criticises the potential insights from optogenetics research, saying:
But the insights-into-mental-illness angle has also been over-hyped, for the following reasons: First, optogenetics is so invasive that it is unlikely to be tested for research purposes on even the most disabled, desperate human patients any time soon, if ever. Second, research on mice, monkeys and other animals provides limited insights–at best–into complex human illnesses such as depression, bipolar disorder and schizophrenia (or our knowledge of these disorders wouldn’t still be so appallingly primitive). Finally, optogenetics alters the cells and circuits it seeks to study so much that experimental results might not apply to unaltered tissue.
Regarding point one: this is still about therapeutic, not research, uses of optogenetics; it also ignores that many patients undergo invasive surgery for epilepsy (which involves actually cutting bits of brain out – surely optogenetics could be a bit better here?) as well as for deep brain stimulation to treat severe depression and Parkinson’s symptoms. Regarding point two: this is a criticism of using animal models in any kind of research rather than optogenetic research in particular – it is valid, but totally besides the point. Regarding point three: if we’re looking to modify the cells in therapies anyway, why does this matter? Stimulating cells with electrodes or drugs changes the way they behave compared to “unaltered” tissue, too!
TL;DR – read this article instead, and don’t pay much attention to this one. It could have made some good points about optogenetics-hype, but didn’t.
*Links from the original article:
OCD and Optogenetics (Scicurious blog)
Implanting false memories in mice (MIT technology review)
Breaking habits with a flash of light (Not Exactly Rocket Science blog)
Optogenetics relives depression in mouse trial (Neuron Culture blog)
How to ‘take over’ a brain (CNN)
A laser light show in the brain (The New Yorker)
** yeah I know, tenuous analogy – but let’s face it, all analogies are pretty shite