Research sheds light on how brain implants can mess with heads
Researchers have shed light on why brain implants are tricky to engineer and often lose their functionality once surgically placed into brain tissue.
The results of a new study, published in the prestigious journal Advanced Science, have revealed how cells of the brain sense continuous motion caused by everyday bodily functions – like breathing or the pulse from a heartbeat. Importantly, if a hard metallic or plastic device is implanted into the soft tissue of the brain, these small, normal movements caused can lead to friction and inflammation of the tissues around the implant, killing off vital brain cells and causing scarring.
The research was carried out by a team at CÚRAM, the Science Foundation Ireland research centre for medical devices based at University of Galway.
Lead researcher on the study, CÚRAM Investigator and Associate Professor at University of Galway’s College of Science and Engineering, Dr Manus Biggs, said: “One of the most exciting parts of our study is the discovery that the cells of the brain use specialised sensors to respond to small frictional forces and that even the most basic, everyday functions can lead to tiny movements which damage the cells adjacent to a brain implant.”
The research also explored possible approaches to help prevent damage to tissue and ultimately increase the lifespan and long term function of implanted electrical devices. Anti-inflammation approaches could be achieved by coating brain implants with soft gels which reduce implant friction and ensure a slow release of these drugs.
The study also evaluated how brain cells attempt to protect themselves from continuous friction by keeping a distance from hard brain implants, essentially creating a fluid-filled blister which prevents direct contact of an implant with the brain tissue. Although this blister which emerges around an implant protects the brain cells from damage, a frequent downside to this defence process is that this structure prevents the neural recording device from operating.
Dr Alex Trotier, who carried out the principal research of the study at CÚRAM and was awarded a PhD by University of Galway, said: “Mitigating scarring of the tissues which surround a recording device implanted into the brain is critical for the development of brain-computer interfaces - devices which allow thoughts to be directly translated into digital signals, signals which can control external devices. The scar tissue that develops around an implanted neural device prevents brain signals from being recorded, rendering the device useless. The potential gamechanger here is for the development of digital implants which can read the brain electrical activity for years at a time.”
Dr Biggs added: “It is hoped that by understanding the cellular repair mechanisms, which occur following the introduction of a brain-implant, that novel devices or drugs can be developed which prevent the scarring and blistering process, paving the way for the emergence of exciting devices which can link the mind directly with advanced technologies. We may see the development of implants which can allow the instantaneous transmission of thoughts from one person to another in the next decade.”
JOURNAL
Advanced Science
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Animal tissue samples
ARTICLE TITLE
Micromotion Derived Fluid Shear Stress Mediates Peri-Electrode Gliosis through Mechanosensitive Ion Channels
Physical and social activities promote healthy brain aging
Physical exercise is associated with a variety of positive health aspects. Numerous studies have shown that regular physical activity has a preventive effect on cardiovascular diseases, diabetes, cancer, high blood pressure and obesity. But how do various leisure activities – physical, social and cognitive – affect brain health in old age? A team of researchers from the University Research Priority Program Dynamics of Healthy Aging and from the Healthy Longevity Center of the University of Zurich (UZH) decided to investigate this question.
To this end, they examined data from a comprehensive longitudinal study on brain development and behavior in old age. The longitudinal study was set in motion 12 years ago by Lutz Jäncke, meanwhile professor emeritus at UZH, who continues to supervise the project together with co-lead Susan Mérillat. The aim of the current research was to investigate the relationships between the thickness of the entorhinal cortex, memory performance and leisure activities in cognitively healthy adults over the age of 65, for a period of seven years.
Exercise and social activity slow down neurodegeneration
The entorhinal cortex, approximately 3.5 millimeters thick, is part of the cerebral cortex in the inner part of the temporal lobe and plays a key role in learning and memory. It is also one of the brain regions that is affected early on in the development of Alzheimer’s disease. “Our findings show that in people who were more physically and socially active at the beginning of the study, the thickness of their entorhinal cortex decreased less over the seven-year period,” says neuropsychologist Jäncke.
The researchers also found that the thickness of the entorhinal cortex is closely linked to memory performance. The less the thickness of this brain structure decreased over the course of the study, the less memory performance was reduced. “Physical exercise and an active social life with friends and family are therefore important for brain health and can prevent neurodegeneration in later life,” says Jäncke.
Brain can be trained like a muscle
It was also shown that higher memory performance at the beginning of the study was associated with a lower decline in memory performance over the course of the study. “These findings support the idea that we have a ‘cognitive reserve’, and that the brain can be trained throughout our lives like a muscle to counteract age-related decline,” says Isabel Hotz, one of the two first authors alongside Pascal Deschwanden. In other words, it pays to be physically, mentally and socially active throughout our lives, including in later life.
Fortunately, many older people in Switzerland already seem to be living by this credo: according to the Swiss Health Survey conducted by the Swiss Federal Statistical Office in 2022, around three quarters of people over 65 get the recommended amount of physical exercise in their daily lives.
JOURNAL
NeuroImage
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Associations between white matter hyperintensities, lacunes, entorhinal cortex thickness, declarative memory and leisure activity in cognitively healthy older adults: A 7-year stud
