The Reading Brainbow
Scientists of renowned research institutions from all over the country have teamed up to tackle what is perhaps one of nature’s most daunting challenges — unraveling the mysteries of the human brain, neuron by neuron. Dubbed the Human Connectome Project (HCP) the proposal was conferred $40 million this past fall by the National Institutes of Health. The grant currently supports collaborating teams of researchers from Harvard University, the University of California, Los Angeles, Washington University in St. Louis and the University of Minnesota.
Connectomics straddles the frontier of neurobiology — a nascent field that strives to chart the intricate network of neural connections within the nervous system by relying on highly sophisticated imaging technology. Such a map, detailing the neural wiring of the brain, is called a connectome.
For years, neuroscientists have merely speculated about neural connectivity, but recent technological innovation at the hands of the Harvard division of the initiative could offer vast insights into the tangled wires of the brain.
Through his work on developing a mouse connectome, Dr. Jeff Lichtman and his associates at the Lichtman Laboratory have designed Brainbow, a visualization technique that labels neural circuitry with fluorescent proteins. In addition, Kenneth Hayworth, who is conducting his postdoctoral research at the Lichtman Laboratory, devised a state-of-the-art machine, the ATLUM (Automatic Tape-collecting Lathe Ultramicrotome), that automatically slices mice brains and prepares them for analysis.
At the microscopic level, the slices could be studied to determine the circuitry of a mouse brain, which harbors approximately 100 million neurons, 1,000 times less than that of the human brain. The team believes a mouse brain connectome, a precursor to its human counterpart, could possibly be drawn up within a realistic time frame.
The connectome initiative has been likened to a more complex version of the Human Genome Project, which sought to identify the makeup of the human genetic code. Yet, while the human genome bears approximately 25,000 genes, neuroscientists estimate the human brain is comprised of a mind-boggling 100 billion neurons, each of which is connected to thousands of other neurons.
It appears as though the impressive effort has generated as much interest as it has controversy. According to the parameters of the proposal, “a high quality and well characterized, quantitative set of human connectivity data” is to be prepared at the end of five years, triggering a wide divide within the scientific community over reception of the Human Connectome Project.
Critics assert that because so much information about the inner workings of the brain remains shrouded in mystery, it is virtually impossible to expect a complete connectome of the human brain within the foreseeable future.
In the wake of an economic crisis, they contend, the valuable grant awarded to the project could be better applied to areas of research with a more plausible outcome. Even if the ambitious investigators manage to generate a connectome of the human brain, skeptics point out that fixed images of brain slices are limited in their use because they cannot reproduce the dynamic nature of the brain. Undeterred, proponents draw attention to the overwhelming medical benefits such an initiative could lead to. If successful, the Human Connectome Project would revolutionize contemporary understanding of mental health and ailments; its results could shed light on psychiatric disorders such as schizophrenia, aging diseases like Alzheimer’s and neurological disorders such as multiple sclerosis. Regardless, PETA remains staunchly opposed to the concept of animal experimentation, claiming on their website, “More lives could be saved and suffering stopped by educating people on the importance of avoiding fat and cholesterol, the dangers of smoking, reducing alcohol and other drug consumption, exercising regularly, and cleaning up the environment than by all the animal tests in the world.”
The bold visionaries have five years until the conclusion of what could be either the collapse of an over-ambitious dream or one of mankind’s most phenomenal accomplishments. The debate, uncertainty and intrigue surrounding the Human Connectome Project could make it well worth the wait.