Starting with light, this is based on a process called neuromodulation. This concerns neuronal communication in the brain. According to Laboratory Roots, when the neurons in the brain communicate the process involves a standard process of molecular neurotransmitters traveling along intersections of nerves (synapses) on the way to stimulate other neurons. This process affects how different parts of the brain interact to accomplish different tasks.
When things work well the process is very effect. However, things go awry when parts of the brain become flooded with neurotransmitters and neuromodulation. How successfully the brain regulates this flow helps to determine mood. Moreover, with diagnosing mental illness or brain disorders, the neuromodulation activities can play an important part in the diagnosis. The limitation is that visualizing the brain has proved to be a difficult task.
Watching nerve activity in real time
This has been advanced through recent research carried out at the Max Planck Florida Institute for Neuroscience together with research teams from the University of Geneva, Korea University and Max Planck Institute of Neurobiology. The new technique involves gene expression and this allows neuromodulation to be observed in real time.
The novel process is called the Inducible Tango technique (or iTango). It is based on a method developed over ten years ago, which triggers neurmodulators to express a green fluorescent protein (and thereby allowing scientists to identify the transmitters). The modified iTango approach is more sophisticated. The new approach consists of directing a blue light on specific neurons. When light hits a neurotransmitter it glows; when the light is switched off or directed elsewhere the glow stops. This allows for a more sophisticated visualization method.
To test out the new light method, the researchers were successfully able to identify two groups of neurons in mice. One group of neurons regulated movement and one the other group was involved in reward circuitry. The researchers not only recorded observations, they were also able to induce and inhibit certain behaviors using the light.
It is hoped long-term that the alternation of behaviors can be attempted on people to address mental health issues tied to depression.
The lead scientist, Dr. Kwon, states in research note: “The light sensitivity provides a huge advantage because you can apply it to basically any signaling. iTango will be useful for visualizing and manipulating the neuronal circuitry that underlies drug-induced behaviors and psychiatric diseases related to neuromodulation, such as mood disorders or schizophrenia.”
Details of the new method are published in the journal Nature Methods, under the heading “Temporally precise labeling and control of neuromodulatory circuits in mammalian brain.”
Essential tremor
Moving from light to sound, in a different research stream neurologists have been studying tremors that result from neurological diseases. Here researchers from Imperial College Healthcare NHS Trust (U.K.) have been looking into whether ultrasound waves can be used to treat the brain and calm the tremors.
At present the study is small-scale, using 20 people, who have been diagnosed with the condition ‘Essential Tremor‘. It typically involves a tremor of the arms, hands or fingers but sometimes involving the head, vocal cords or other body parts during voluntary movements such as eating and writing. It is distinct from Parkinson’s disease. The cause of this condition is probably the abnormal firing of electrical circuits in the brain.
The technique used on the patients is referred to as ‘MRI-guided focused ultrasound for the brain.’ This is a special type of magnetic resonance imaging (MRI). MRI scans are required so that medics can accurately focus heat energy from ultrasound waves to very specific parts of the brain. According to Laboratory Roots, the energy from this breaks down the electrical circuits in the brain that have gone awry. Here the sound waves cause molecules to vibrate; in doing so they create heat and energy. This heat functions to destroy cells that are firing wrongly.
The process is non-invasive and if successful it could be rolled out to a wider patient population. Similar trials have taken place in the U.S. and Japan, with positive results reported. The ultrasound machine, Exablate Neuro, is produced by Insightec, a technology firm based in Israel.
With the British trial, one patient, a Mr. Lucas, was interviewed by the BBC. He stated: “Since the treatment I have been able to write my own name for the first time in many years and taken my wife out for a lovely meal without fear of embarrassing myself. I will also be able to go back to using my right hand which will allow me to take on more painting and decorating jobs.”
The trial results will indicate whether the process is successful for all patients and how effective the focusing of an ultrasound beam transcranially into the brain actually is.
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week examined whether B12 vitamins can help boost brain function. This centered on studies where seniors eat either peanut butter or Marmite each day. The week before we also covered a food related topic, weighing in on whether a medicinal diet could help to combat type 1 diabetes.
