Visualising Plastic Changes to the Brain

Tinnitus, migraine, epilepsy, depression, schizophrenia, Alzheimer's: all these are examples of diseases with neurological causes, the treatment and study of which is more and more frequently being carried out by means of magnetic stimulation of the brain. However, the method's precise mechanisms of action have not, as yet, been fully understood. The work group headed by PD Dr Dirk Jancke from the Institut für Neuroinformatik was the first to succeed in illustrating the neuronal effects of this treatment method with high-res images.

Transcranial magnetic stimulation (TMS) is a painless, non-invasive stimulation method, where an electromagnetic coil held above the head is used to generate a strong magnetic field. This method is deployed to activate or inhibit specific brain regions. Even though the number of its medical applications is constantly on the increase, TMS' precise neuronal mechanisms of action are not, as yet, very well understood. That is because imaging used for humans, such as fMRI (functional magnetic resonance imaging), do not possess the temporal resolution necessary for recording neural activities in milliseconds. More rapid measurement methods, such as EEG or MEG, on the other hand, are affected by the induced magnetic field, with the results that strong interferences are generated that cover important information regarding immediate TMS-based changes to brain activities.

High-res images of TMS effects have now for the first time been successfully generated by RUB researchers in animal testing. The work group headed by PD Dr Dirk Jancke, Institut für Neuroinformatik, utilises voltage-sensitive dyes which, anchored in cell membranes, send out fluorescent light signals once neurons get activated or inhibited. By using light, the researchers avoided the problem of measurement of artefacts occurring due to magnetic fields. "We can now demonstrate in real time how one single TMS pulse suppresses brain activity across a considerable region, most likely through mass activation of inhibiting brain cells," says Dr Jancke. With higher TMS frequencies, each additional TMS pulse generates an incremental increase in brain activity. "This results in a higher cortical activation state, which opens up a time window for plastic changes," explains Dr Vladislav Kozyrev, the first author of the study.

The increased neuronal excitability may be utilised to effect specific reorganisation of cell connections by means of targeted learning processes. For example, through visual training after TMS, the ability to identify image contours improves; moreover, a combination of these methods enhances contrast perception in patients with amblyopia - a disorder of sight acquired during child development. For many neurological diseases of the brain, such as epilepsy, depression and stroke, specific models have been developed. "Deployed in animal testing, our technology has delivered high spatiotemporal resolution imaging data of cortical activity changes," says Dirk Jancke. "We are hoping that these data will enable us to optimise TMS parameters and learning processes in a targeted manner, which are going to be used in future to adapt this technology for medical treatment of humans."

Funding: The German Research Foundation has financed the study, e.g. under the framework of Bochum's SFB 874 "Integration and Representation of Sensory Processes (Project A2, Eysel/Jancke)".

V. Kozyrev, U.T. Eysel, D. Jancke (2014): Voltage-sensitive dye imaging of transcranial magnetic stimulation-induced intracortical dynamics, PNAS, doi:10.1073/pnas.1405508111

Most Popular Now

Researchers Find Telemedicine may Help R…

Low-value care - medical tests and procedures that provide little to no benefit to patients - contributes to excess medical spending and both direct and cascading harms to patients. A...

AI Revolutionizes Glaucoma Care

Imagine walking into a supermarket, train station, or shopping mall and having your eyes screened for glaucoma within seconds - no appointment needed. With the AI-based Glaucoma Screening (AI-GS) network...

AI may Help Clinicians Personalize Treat…

Individuals with generalized anxiety disorder (GAD), a condition characterized by daily excessive worry lasting at least six months, have a high relapse rate even after receiving treatment. Artificial intelligence (AI)...

Accelerating NHS Digital Maturity: Paper…

Digitised clinical noting at South Tees Hospitals NHS Foundation Trust is creating efficiencies for busy doctors and nurses. The trust’s CCIO Dr Andrew Adair, deputy CCIO Dr John Greenaway, and...

Mobile App Tracking Blood Pressure Helps…

The AHOMKA platform, an innovative mobile app for patient-to-provider communication that developed through a collaboration between the School of Engineering and leading medical institutions in Ghana, has yielded positive results...

AI can Open Up Beds in the ICU

At the height of the COVID-19 pandemic, hospitals frequently ran short of beds in intensive care units. But even earlier, ICUs faced challenges in keeping beds available. With an aging...

Can AI Help Detect Cognitive Impairment?

Mild cognitive impairment (MCI) can be an early indicator of Alzheimer's disease or dementia, so identifying those with cognitive issues early could lead to interventions and better outcomes. But diagnosing...

Customized Smartphone App Shows Promise …

A growing body of research indicates that older adults in assisted living facilities can delay or even prevent cognitive decline through interventions that combine multiple activities, such as improving diet...

New Study Shows Promise for Gamified mHe…

A new study published in Multiple Sclerosis and Related Disorders highlights the potential of More Stamina, a gamified mobile health (mHealth) app designed to help people with Multiple Sclerosis (MS)...

AI Model Predicting Two-Year Risk of Com…

AFib (short for atrial fibrillation), a common heart rhythm disorder in adults, can have disastrous consequences including life-threatening blood clots and stroke if left undetected or untreated. A new study...

Patients' Affinity for AI Messages …

In a Duke Health-led survey, patients who were shown messages written either by artificial intelligence (AI) or human clinicians indicated a preference for responses drafted by AI over a human...

New Research Explores How AI can Build T…

In today’s economy, many workers have transitioned from manual labor toward knowledge work, a move driven primarily by technological advances, and workers in this domain face challenges around managing non-routine...