Move over MRI scanners, BigBrain does it so much bigger. Actually, I’m a bit ahead of myself, the MRI looks likely to be around for a good while yet. Still, the news is that certain neuroscientists are giving themselves a (deserved) pat on the back for turning out something they refer to as a BigBrain atlas. The kit allows scientists to study a three-dimensional virtual brain to the extent of observing inter-cellular activity with a resolution 50 times better than those tired old MRI (magnetic resonance imaging) scanners.
Medical breakthrough, you may be wondering? Well yes, but it will take time to realize the full benefits and actually BigBrain can’t do everything an MRI scanner can. So what are the perceived benefits? Well, an MRI scanner examines the overall structure of a real brain, whereas BigBrain represents a composite model based on many thousands of slices examined from actual organs. It also bridges a gap between; at one extreme the global scans from the MRI, and the other the microscope slides that allow us examine very small samples of tissue.
BigBrain represents a kind of wiring diagram, the likes of which we haven’t seen before. It will act as reference against which variations and abnormalities can be compared. It should help to target, with some degree of accuracy, the location of disturbances that give rise to epilepsy, Alzheimer’s, Parkinson’s and more. All of which leads me to wonder about depression.
People with depression get a pretty raw deal when it comes to assessment and treatment. It doesn’t help when we are still debating the meanings, causes and course of depression and this is reflected in the somewhat ad hoc nature of treatments and therapeutic outcomes. I’ll be interested to see how BigBrain shapes up when it comes to tackling depression!
But not all is lost. Scans it appears may be able to help with treatment prediction. Helen Mayberg, M.D., and colleagues of Emory University, Atlanta, have identified a specific area of the brain that determines whether cognitive behavior therapy (CBT) or the drug escitalopram (a serotonin reuptake inhibitor) will be most effective as a treatment method.
For those of you interested in the details, an area of the brain known as the anterior insula, thought to be important emotional regulation, decision-making and other cognitive tasks, is key. Medication, yoga, mindfulness training and deep brain stimulation all result in changes to the anterior insula. After a series of trials the research team concluded that activity in one part of the anterior insula signaled a much higher likelihood of a positive response to CBT while higher activity in a different area pointed to better effects with the SSRI medication.
It’s all encouraging stuff. But have you seen the size of an MRI or a PET scanner? Maybe when we can scale down the size of scanners to the point where they fit into the surgery of the family doctor (and speed things up) the process may become less unwieldy and more likely to be used as a diagnostic tool. What’s that saying about every journey starting with a single step?
McGrath et al (2013) Toward a Neuroimaging Treatment Selection Biomarker for Major Depressive Disorder. JAMA Psychiatry. http://archpsyc.jamanetwork.com/article.aspx?articleid=1696349
Published On: June 26, 2013