For those who would like background on Karl Deisseroth, whose lab is involved in this work, I recommend this New Yorker article:<p><a href="http:&#x2F;&#x2F;www.newyorker.com&#x2F;magazine&#x2F;2015&#x2F;05&#x2F;18&#x2F;lighting-the-brain" rel="nofollow">http:&#x2F;&#x2F;www.newyorker.com&#x2F;magazine&#x2F;2015&#x2F;05&#x2F;18&#x2F;lighting-the-br...</a>