Zombie Dreams

Do Zombies Dream of Undead Sheep?

That’s the title of an amusing and very informational book if you want to learn the fundamentals of neuroscience. The authors, Verstynen and Voytek, are both neuroscience professors (at Carnegie Mellon and UCSD respectively). And they share a love of zombie movies – Night of the Living Dead and more. If I ever get around to writing my introductory chemistry-in-the-guise-of-magic book, Zombies will be my lodestone. But I will have to come up with a very different title since I don’t plan on riffing off Philip K. Dick’s marvelous Do Androids Dream of Electric Sheep (introduced to the wider world via the movie Blade Runner).

Seven years ago, while preparing to teach a unit on neuroscience in an interdisciplinary scientific inquiry course, I taught myself some basics of the human brain. Zombies is a good refresher; I had remembered some but forgotten a lot. Even better, there are many references to the chemistry of neuroscience in Zombies. I’ve been paying attention to different molecules, looking up structures, and trying to understand evolutionary relationships (given my origin-of-life interests). Living systems in general, and human beings in particular, are remarkable organisms. I have new appreciation for the cerebellum and how it ‘computes’ small adjustments to complex motor movements, or the hippocampus helping you track through your spatial awareness. It’s amazing that we can function as well as we do, without getting our wires crossed (both electrical and chemical signals). Until something goes off course, of course.

In addition to the chemistry, I enjoy the historical vignettes in Zombies. Neuroscience was founded on investigating people (and animals) suffering all manner of maladies and damages to the nervous system. I learned about Mike the Headless Chicken, apparently a celebrity in the 1940s. There was also an operation on a virile rooster helped progress knowledge about the cerebellum in the nineteenth century. The vignette I found most interesting was zombification in Haiti; I did not know much about the process and how the belief in zombies evolved, but the authors refer to The Serpent and the Rainbow, a book that is now on my reading list so I can learn more about Haitian magic. Two chemicals of interest in the process are tetrodoxin and datura – yes, there is a close connection between chemistry and magic!

The approach taken by Zombies is to examine different parts of the system (involving the brain, but also many other parts of the human body), and consider what happens when each part is impaired thereby giving rise to different behavior. Zombie behavior has certain (stereotypical) characteristics, a lumbering gait, insatiable hunger, and somehow a knack for finding living flesh for food instead of trying to eat fellow undead or their undead sheep. Which parts of the brain affect these? Among other things the authors examine sleep, dreaming, wakefulness; and they suggest that zombies have impaired sleep cycles. How exactly might they be impaired? I learnt about the reticular activating system (RAS), the tuberomamillary nucleus (TMN), the ventrolateral preoptic nucleus (VLPO), and the swath of neurotransmitters involved in waking up and falling asleep. Zombies is a science book at heart, just with a lot of zombie jokes thrown in. And if you can bear the zombie humor, the book is a marvelous read!