Monday, November 12, 2012

The Holy Grail of Neuroscience

My first post! Thank you for visiting my neuroscience blog and welcome! The goal of my blog is to encourage/induce/stimulate advocacy, enthusiasm, transparency, and a public understanding of neuroscience. How might I accomplish such a lofty goal? Through what else? The currency of science: primary research articles. Aside from the discussion of new and exciting research articles, I will post information that may be educational (e.g. My recent favorite neuroscience education application for children and can be found on the Apple App Store: Ned The Neuron from Kizoom Labs), humorous, etc, but all with a focus on science. I hope everyone enjoys my blog, finds it informative, and engages in discussions through comments on these posts. Deciding what article I'd summarize for my first post was extremely challenging. But, I thought about the recent Society for Neuroscience meeting in New Orleans this year and asked myself, "What was the hot topic?" And, although numerous topics appeared to be at the forefront of research this year, a specific research technique is what came to mind: optogenetics. Optogenetics is a burgeoning technical discipline in the neuroscience community because it provides us lab junkies with an exciting new way to control and study brain function using light. Using a light-sensitive ion channel (Channelrhodopsin-2) isolated from single-celled algae, Karl Deisseroth's group at Stanford in 2005 was able to rapidly control mammalian neurons with light after they had been equipped with this foreign gene. An important question you should be asking yourself is, "Who cares?" Well, more recent uses of this technique have allowed researchers to do extremely neat experimental manipulations that could potentially treat prevalent diseases like epilepsy in the way that implanted defibrillators control heart attacks. But, I couldn't give due credit to the description of the potential utility of this lab technique like Edward Boyden could (a graduate student at the time on Karl Deisseroth's 2005 publication). So watch his excellent TED talk here and then read below to see why this technique has allowed us to begin grasping the holy grail of neuroscience:


So, what is the holy grail of neuroscience? Treating all neurological/psychiatric diseases of course! Well, this is somewhat unrealistic, but depending on the neuroscientist you ask, there might be many different answers to this question. However, most would agree that one of the many holy grails of neuroscience might be to discover the biological basis of memory. How are specific memories encoded in the brain? How are they retrieved? Can they be retrieved in diseases like Alzheimer's, or are they gone forever? In what I think will soon become referred to as a seminal publication, Nobel prize winner, Susumu Tonegawa's lab at M.I.T. found that using optogenetics (and other genetic manipulations), they were able to label and stimulate cells that were active in mice while these animals learned a 'fear behavior'. Upon light stimulation, these same cells were activated and induced the recall of the memory associated with that behavior. This suggested that the subset cells that were labelled during the fear behavior (known as fear conditioning), were responsible for encoding the memory. To date, numerous experiments involving investigations of learning and memory often use the theoretical approach of what we call, "loss of function" evidence which can be thought of in terms of logic statements: If X is removed from process Y, and process Y fails, X is required for process Y function. But this study provided the research community with "gain of function" evidence; turning on these cells evoked the recall of a memory, rather than studies that destroyed brain regions and attempted to determine if the animals could still 'remember'. Strong evidence provided in this study suggest how, in part, memories are stored in the brain and could be the beginning of a field that will soon explode.

My first article discussion is somewhat short, but I want people to be excited about what's to come, and with that, I will leave you with a quote from the neuroscientist whose book, "A Brief Tour of Human Consciousness," is the reason I am in neuroscience research today:

“The theoretical agenda is to understand the neural basis of human behavior—the question of how the activity of millions of tiny wisps of protoplasm in the brain gives rise to all the richness of our conscious experience.” Vilayanur Ramachandran.


NeuroscienceDC



Liu, X., Ramirez, S., Pang, P., Puryear, C., Govindarajan, A., Deisseroth, K., & Tonegawa, S. (2012). Optogenetic stimulation of a hippocampal engram activates fear memory recall Nature DOI: 10.1038/nature11028