Human Brain Research – The Developing Tools
Innovation. Technology breakthroughs. Interdisciplinary efforts. All of this is providing the opportunity for more scientific and comprehensive brain research. More specifically, the convergence of breakthroughs in biogenetics, nanotechnology, and neuroscience; coupled with advanced microelectronics and data processing; has led to new tools and devices for brain research and understanding. We highlight a few of these to show the possibilities.
First there are advanced imaging technologies that have led to new techniques and instrumentation that is already being used. Short summaries of the most common are provided in a post on psychcentral.com. (1) These include:
- PET (Positron Emission Tomography). PET uses small amounts of radioactive materials injected into the body, a special camera, and a computer to evaluate organ and tissue functions. By identifying changes at the cellular level, PET appears be able to detect which parts of the brain are affected during specific tasks.
- Variations of Magnetic Resonance Imaging (MRI) such as Functional MRI (fMRI) and Diffusion MRI (also called Diffusion Tensor Imaging – DTI). With fMRI the small changes in blood flow that occur with brain activity are measured and mapped. Thus, it is possible to determine which parts of the brain are handling critical functions or to evaluate the effects of stroke or other disease. With DTI the diffusion of water molecules in the brain is measured. Since water molecules within brain tissue tend to diffuse most rapidly along parallel bundles of fibers, this makes it possible to estimate the location, orientation, and anisotropy of the brain’s white matter tracts. In other words, it is possible to measure the pathways and structure of fiber nerve bundles connecting various parts of the brain. This understanding of which part of the brain is connected (or not connected) to which other parts can be used to investigate brain “malfunctions” due to injury or disease.
- Magnetoencephalography (MEG). Instead of measuring electrical impulses, MEG measures magnetic fields outside the head, produced by electrical activity occurring naturally in the brain. Thus, it is possible to produce far more precise and higher resolution images of the brain than before and even to determine the function of various parts of the brain. To do this, very sensitive arrays of magnetometers called SQUIDS (superconducting quantum interference devices developed by quantum physicists) are used. Typically, these sensors are housed in a cooled, helmet-shaped container in which the subject places on their head during testing.
To summarize, the above tools allow researchers to identify the parts of the brain that are active during a specific task or event by showing on a screen the parts of the brain that “light up” under different circumstances. Why is this important? Unlike earlier beliefs, it has now been observed that even relatively simple tasks require the activation of numerous and specific interconnected parts of the brain. Therefore, understanding brain connections and interactions is much more important in addressing brain issues such as injury or dementia than was previously thought.
But these imaging techniques are only a start. Following are a few examples of developing, longer-range possibilities.
- In one example, real time imaging of interactions at the cellular level, coupled with advanced data processing, is being used to reveal patterns of neural activity. Specifically, “Scientists have devised a new system that lets them watch human neurons grown in the lab find and form connections with their signaling partners, an essential process in developing human brains. The processing of “wiring up” is thought to go awry in a number of serious disorders, including autism, epilepsy and schizophrenia – but it’s hard to study.” (2)
- And there is another experimental approach to creating brain wiring diagrams that combines genetic engineering and nanoscale imaging. This technique monitors biofluorescence in insect brains to create maps of the neural connections of the entire brains. In other words, “Scientists have developed new technology that allows them to see which neurons are talking to which other neurons in live, genetically engineered fruit flies.” This technology which traces the flow of information across synapses is called TRACT (Transneuronal Control of Transcription). “TRACT allows researchers to observe which neurons are “talking” and which neurons are “listening” by prompting the connected neurons to produce glowing proteins.” (3)
- And then there is the gene editing technology called CRISPR. This technique has been used to create genetic mutations that have been associated with neurodevelopmental disorders, making it possible to study these “defects” in the laboratory. (4)
- One final example. There is a new, high-sensitivity, laser-based technique that can be used to look inside a person’s skull and measure brain blood flow. This technique, based on Diffuse Correlation Spectroscopy (DCS), is called “interferometric diffusing wave spectroscopy,” or iDWS. “Laser light is shined on the head; as photons from the laser pass through the skull and brain, they are scattered by blood and tissue. A detector placed elsewhere on the head, where the photons make their way out again, picks up the light fluctuations due to blood motion.” (6) The information gathered about blood flow can be used to help patients with traumatic brain injuries and strokes.
As the above examples show, progress is being made rapidly in developing new tools for brain research and understanding. But all of this is just a start. In future blogs we will give additional examples of new techniques, how they are being utilized, and even some results. You are welcome to comment or add to our list.
- Michael Demitri, “Types of Brain Imaging Techniques,” July 17, 2016, https://psychcentral.com/lib/types-of-brain-imaging-techniques/
- Sergiu P. Pasca, “New Technique Lets Researchers Watch Human Brain Circuits Begin to Wire-Up,” July 18, 2017, https://www.bbrfoundation.org/content/new-technique-lets-researchers-watch-human-brain-circuits-begin-wire
- “New technology will create brain wiring diagrams,” California Institute of Technology, January 12, 2018, https://www.sciencedaily.com/releases/2018/01/180112095938.htm
- Michael Talkowski, “Genetic Anomalies Frequently Associated with Neurodevelopmental Disorders Can Now Be Efficiently Recreated in the Lab,” April 11, 2016, https://www.bbrfoundation.org/content/genetic-anomalies-frequently-associated-neurodevelopmental-disorders-can-now-be-efficiently
- “New technology for measuring brain blood flow with light,” University of California – Davis, April 11, 2018, https://www.sciencedaily.com/releases/2018/04/180427144549.htm