Category: Brain

Coherent hemodynamics spectroscopy (CHS), developed by Tufts professor Sergio Fantini, measures blood flow, blood volume, and oxygen consumption in the brain. The goal is to pinpoint and monitor, real time and non invasively, brain damage from stroke, traumatic injury, or vascular dementia. It can also be used to study how blood flow is regulated in the healthy brain.

CHS uses noninvasive laser diodes that emit near infrared light, delivered to the scalp by fiber optics. Light waves are absorbed by blood vessels in the brain. Remaining light is reflected back to sensors, resulting in optical signals that oscillate with time as a result of the heartbeat, respiration, or other sources of blood pressure variation.  Algorithms analyze the light signals, enabling the model to evaluate blood flow and the way the brain regulates it.

Benjamin Long and colleagues at the University of Bristol have developed invisible 3D object holograms that can be felt and seen in mid-air using ultrasound. Potential uses include helping surgeons “feel” the differences between materials in a CT scan to diagnose disease, or, combined with a VR headset, to rehearse surgeries.

High-frequency sound waves  are pulsed from miniature speakers that exert pressure on one’s hand to create the feel of haptic holograms. A Leap Motion sensor tracks hand positions to decide where in the air to create the object. Sound waves are projected onto a layer of oil, and shape depressions and movements can be seen on the surface.

Stanford‘s NeuroCircuit initiative, led by Amit Etkin and Stephen Baccus,  attempts to locate brain circuits responsible for mental illness and develop better, noninvasive TMS and ultrasound treatment techniques.  Their stated challenge:  “A major hurdle that has prevented our understanding of cause and effect in the brain is the inability to directly manipulate brain activity and connections in a precise and flexible manner throughout the brain.”

In their lab, TMS is used to stimulate one part of the brain while researchers look for reactions elsewhere. The hope is to map the relationship between brain circuits and identify the circuits that underlie mental health conditions.

Etkin is trying to improve TMS so that it can reach deeper brain structures and be more targeted.   He believes that this is required to effectively treat depression, anxiety and PTSD.

Baccus  and colleagues are developing a way to use ultrasound for brain stimulation.  They are trying to direct it deep within the brain at a frequency that can stimulate nerves without harming them. If the team is successful, ultrasound could be a more targeted and focused tool than TMS for remotely stimulating circuits that generate mental illness.

University College London professor Geoffrey Raisman transplanted cells from a quadriplegic man’s nose into his spinal cord, enabling him to walk (with assistance) for the first time in 4 years.  The paper describing the transplant was published in Cell Transplantation this week.

In 1969, Professor Raisman discovered that damaged nerve cells can form new connections.  In 1985, he identified a type of nose cell, called an olfactory ensheathing cell, that allows nerve fibers to regenerate into the brain.

In the first of two operations, the surgeons removed one of the patient’s olfactory bulbs from high in his nose, and grew the OECs in culture.  Two weeks later, using 100 micro-injections on each side of the site, they transplanted the cultured OECs into his severed spinal cord, using a strip of nerves from his ankle to bridge the gap.

The OECs were used to spur the spinal nerve fibers to regrow across the gap, using the ankle nerve grafts as a bridge.