Neuroimaging Techniques for Assessing Brain Function

Using MRI, engineers have found a way to detect light deep in the brain. New technique could enable detailed studies of how brain cells develop and communicate with each other. MIT. May 10, 2024 Excerpt: MIT engineers have now developed a novel way to detect light, known as bioluminescence, in the brain : Blood vessels of the brain have been engineered to express a protein to dilate in the presence of light. Dilation can then be observed with magnetic resonance imaging (MRI), allowing researchers to pinpoint the source of light. “A well-known problem we face in neuroscience, as well as other fields, is that it’s very difficult to use optical tools in deep tissue. One of the core objectives of our study was to come up with a way to image bioluminescent molecules in deep tissue with reasonably high resolution,” says Alan Jasanoff, an MIT professor of biological engineering, brain and cognitive sciences, and nuclear science and engineering. Bioluminescent proteins are found in many organisms, including jellyfish and fireflies. Scientists use these proteins to label specific proteins or cells, whose glow can be detected by a luminometer. One of the proteins often used for this purpose is luciferase, which comes in a variety of forms that glow in different colors. Jasanoff’s lab, specializes in developing new ways to image the brain using MRI; and, to find a way to detect luciferase deep within the brain. To achieve this goal, a method was developed for transforming blood vessels of the brain into light detectors. A popular form of MRI works by imaging changes in blood flow in the brain. Researchers engineered the blood vessels to respond to light by dilating. “Blood vessels are a dominant source of imaging contrast in functional MRI and other non-invasive imaging techniques, so we thought we could convert the intrinsic ability of these techniques to image blood vessels into a means for imaging light, by photosensitizing the blood vessels themselves,” Jasanoff says. Note: Researchers engineered blood vessels to express a bacterial protein Beggiatoa photoactivated adenylate cyclase (bPAC). When exposed to light, this enzyme produces a molecule called cAMP, which causes blood vessels to dilate. When blood vessels dilate, it alters the balance of oxygenated and deoxygenated hemoglobin, which have different magnetic properties. This shift in magnetic properties can be detected by MRI. BPAC responds specifically to blue light, which has a short wavelength, detecting light generated within close range. The researchers used a viral vector to deliver the gene for bPAC specifically to the smooth muscle cells that make up blood vessels. When this vector was injected in rats, blood vessels throughout a large area of the brain became light-sensitive. Publication: Nature Biomedical Engineering 10 May 2024 Imaging bioluminescence by detecting localized haemodynamic contrast from photosensitized vasculature

What if Next-Gen fMRI was a biological hardware able to show how the brain balances its oxygen supply and demand while multitasking?   Traditional methods like fMRI have given us some insight, but what if we could observe this process with even greater detail? Enter this groundbreaking work [in the comments] that used a bioluminescent oxygen indicator, Green enhanced Nano-lantern (#GeNL), to examine oxygen partial pressure in different parts of the mouse brain. This approach allowed them to observe oxygen dynamics at high spatial and temporal resolution, a feat not possible with traditional fMRI. Their findings? The discovery of transient and spatially restricted periods of hypoxia, or #hypoxicpockets. These pockets are linked to the abrogation of local capillary flow. Interestingly, physical activity such as running reduces the occurrence of these hypoxic regions by 52% compared with rest. Of course, this is very early-stage research, but understanding the dynamics of brain tissue oxygen tension could have significant implications for psychiatry. Many psychiatric conditions, such as depression, anxiety, and schizophrenia, are associated with alterations in brain function and structure. These alterations often involve changes in blood flow and oxygenation. The ability to observe “hypoxic pockets” in the brain could provide new insights into these disorders. Moreover, the finding that physical activity reduces the occurrence of hypoxic regions aligns with the known benefits of exercise for mental health. This study not only provides unprecedented spatio/temporal/computational insight into cortical oxygen dynamics in awake, behaving animals but also establishes a tool to delineate the importance of oxygen tension in neurophysiological processes. It’s a testament to how far we’ve come in our quest to understand the brain and its intricate workings, and how much further we can go with the right tools and approaches. It opens up new avenues for understanding neural processes while highlighting the importance of interdisciplinary research in advancing neuroscience research across all phases of the translational pipeline, from basic science to services and interventions. What are your thoughts on the potential of this new technology?

𝐍𝐨𝐭 𝐀𝐥𝐥 𝐈𝐧𝐣𝐮𝐫𝐢𝐞𝐬 𝐒𝐡𝐨𝐰 𝐔𝐩 𝐨𝐧 𝐚 𝐒𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐌𝐑𝐈 After a truck crash, victims are often told their scans are “normal” — even when they know something is wrong. The truth is, standard imaging cannot always detect certain types of trauma. That is where advanced tools come in. Here are a few lesser-known imaging techniques that can reveal hidden injuries: 🧠 DTI (Diffusion Tensor Imaging) This advanced form of MRI maps the white matter tracts in the brain. It helps identify microstructural damage, especially in cases of traumatic brain injury. DTI is often used when a patient has cognitive or emotional symptoms, but a regular MRI appears normal. 🔬 SWI (Susceptibility-Weighted Imaging) SWI is highly sensitive to blood products and microbleeds in the brain. It can detect tiny areas of damage caused by shearing forces in a crash, even when other imaging shows nothing. 🧲 fMRI (Functional MRI) fMRI shows how the brain is functioning in real time. It is used to assess which parts of the brain are active during specific tasks, helping neurologists pinpoint areas affected by injury or trauma. 🧍♂️ SPECT Scan (Single Photon Emission Computed Tomography) SPECT measures blood flow in the brain and can detect underactive areas after injury. It is sometimes used in cases involving memory loss, personality changes, or post-concussive symptoms. 📉 Upright MRI Some injuries to the spine or neck only show when the body is bearing weight. Upright MRI allows the patient to be scanned in a seated or standing position, revealing instability or disc damage that standard supine imaging can miss. At Shaked Law, we understand that not all injuries are visible with basic tools. That is why we work with the right experts and push for the proper testing; especially when the symptoms say more than the scans. If you are still in pain after a crash and being told “everything looks fine,” you deserve a second look and real answers. 🌐 www.shakedlaw.com 📞 305-937-0191

NEW: Brain Activity - Now Audiovisual Novel technique to convert complex neuroimaging real-time data into audiovisual format. Complex neuroimaging data can be explored through translation into an #audiovisual format – a video with accompanying musical soundtrack – to help interpret what happens in the brain when performing certain behaviors (like running). New technique: •  Identifies patterns in large #datasets •  enhances the understanding of the dynamic relationship •  between #neuronal activity and #behavior. 👉  Transforming brain activity and blood flow data from behaviors like running into synchronized music sounds, accompanied by #video, offers a new approach to explore the brain’s intricate workings. Multiple variables can be encoded as different musical instruments, letting the observer differentiate and track multiple #dynamic parameters in parallel. 👉  The toolkit represents a significant step forward in neuroscientific research, enabling scientists to intuitively screen and interpret vast amounts of #brain #data. PLOS ONE | February 21, 2024 -- More info & links in Comments -------------------- David Thibodeaux, Mohammed Shaik, MD, PhD, Sharon Kim, Venkatakaushik Voleti, Hanzhi Zhao, Sam Benezra, Chinwendu Nwokeabia, Elizabeth M. C. Hillman. Columbia's Mortimer B. Zuckerman Mind Brain and Behavior Institute, Columbia University #columbia #neurosciences #future #technology #neurotech #innovation #monitoring #visualization #startups #medtech #biotech #sensors #neuroimaging #precisionmedicine #personalizedmedicine #medicine #plasticity #network #bci #behavioral #science #linkedin #news #communication #education #ai #engineering #devices #3d #optical #machinelearning #pattern #recognition #neuroscience #futuristic #movement