Lifeboat Foundation

Consciousness is comprised of arousal (i.e., wakefulness) and awareness. Substantial progress has been made in mapping the cortical networks that modulate awareness in the human brain, but knowledge about the subcortical networks that sustain arousal is lacking. We integrated data from ex vivo diffusion MRI, immunohistochemistry, and in vivo 7 Tesla functional MRI to map the connectivity of a subcortical arousal network that we postulate sustains wakefulness in the resting, conscious human brain, analogous to the cortical default mode network (DMN) that is believed to sustain self-awareness. We identified nodes of the proposed default ascending arousal network (dAAN) in the brainstem, hypothalamus, thalamus, and basal forebrain by correlating ex vivo diffusion MRI with immunohistochemistry in three human brain specimens from neurologically normal individuals scanned at 600–750 µm resolution. We performed deterministic and probabilistic tractography analyses of the diffusion MRI data to map dAAN intra-network connections and dAAN-DMN internetwork connections. Using a newly developed network-based autopsy of the human brain that integrates ex vivo MRI and histopathology, we identified projection, association, and commissural pathways linking dAAN nodes with one another and with cortical DMN nodes, providing a structural architecture for the integration of arousal and awareness in human consciousness. We release the ex vivo diffusion MRI data, corresponding immunohistochemistry data, network-based autopsy methods, and a new brainstem dAAN atlas to support efforts to map the connectivity of human consciousness.

One sentence summary We performed ex vivo diffusion MRI, immunohistochemistry, and in vivo 7 Tesla functional MRI to map brainstem connections that sustain wakefulness in human consciousness.

BF has a financial interest in CorticoMetrics, a company whose medical pursuits focus on brain imaging and measurement technologies. BF’s interests were reviewed and are managed by Massachusetts General Hospital and Mass General Brigham HealthCare in accordance with their conflict-of-interest policies.

Is consciousness a scientific problem to be solved? Or a philosophical problem that will remain a mystery? What do scientists who study the brain think? And why do they think the way they do? These leading brain scientists share their intimate ideas about how the brain generates consciousness.

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Learn more about the Cognitive Science Student Association and the California Cognitive Science Conference at https://cssa.berkeley.edu.

Amy Arnsten — Yale University.

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The largest animals do not have proportionally bigger brains — with humans bucking this trend — a new study published in Nature Ecology and Evolution has revealed.

Researchers at the University of Reading and Durham University collected an enormous dataset of brain and body sizes from around 1,500…

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Toronto, Ontario —A new ultra-high-performance brain PET system allows for the direct measurement of brain nuclei as never before seen or quantified. With its ultra-high sensitivity and resolution, the NeuroEXPLORER provides exceptional brain PET images and has the potential to spur advances in the treatment of many brain diseases. This research was presented at the 2024 Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting, and the grouping of images highlighting targeted tracer uptake in specific brain nuclei has been selected as the 2024 SNMMI Henry N. Wagner, Jr., Image of the Year.

Each year, SNMMI chooses an image that best exemplifies the most promising advances in the field of nuclear medicine and molecular imaging. The state-of-the-art technologies captured in these images demonstrate the capacity to improve patient care by detecting disease, aiding diagnosis, improving clinical confidence, and providing a means of selecting appropriate treatments. This year, the SNMMI Image of the Year was chosen from more than 1,500 abstracts submitted for the meeting.

The image quality of PET systems has improved in recent years, mostly by increases in sensitivity, including enhanced time-of-flight capabilities. However, these systems have shown only minimal improvement in intrinsic resolution. To address these issues, researchers designed the NeuroEXPLORER PET scanner with a focus on ultra-high sensitivity and resolution, as well as continuous head motion correction.

The largest animals do not have proportionally bigger brains—with humans bucking this trend—a study published in Nature Ecology & Evolution has revealed.

Researchers at the University of Reading and Durham University collected an enormous dataset of brain and body sizes from around 1,500 species to clarify centuries of controversy surrounding brain size evolution.

Bigger brains relative to body size are linked to intelligence, sociality, and behavioral complexity—with humans having evolved exceptionally large brains. The new research reveals the largest animals do not have proportionally bigger brains, challenging long-held beliefs about brain evolution.

Researchers at the Okinawa Institute of Science and Technology (OIST) have developed a potentially transformative approach to treating Alzheimer’s disease, A team from the former Cellular and Molecular Synaptic Function Unit have reported significant progress in reversing cognitive decline and restoring memory in transgenic mice using a synthetic protein. The findings, published in Brain Research, offer hope for a viable treatment to alleviate the debilitating symptoms associated with this neurodegenerative condition.

“We successfully reversed the symptoms of Alzheimer’s disease in mice,” explained Dr Chia-Jung Chang, first author of the study and presently a member of the Neural Computation Unit at OIST. “We achieved this with a small, synthetic peptide, PHDP5, that can easily cross the blood-brain barrier to directly target the memory center in the brain [1].”

Longevity. Technology: There is a pressing need to find effective treatments for Alzheimer’s; along with other forms of dementia, this debilitating disease currently affects approximately 55 million people worldwide, and this number is predicted to nearly double every 20 years, reaching 78 million in 2030 and 139 million in 2050. As well as a health burden, Alzheimer’s is an economic burden – the annual global cost of dementia has now rocketed to more than US$1.3 trillion, with a projected rise to US$2.8 trillion by 2030 on the horizon [2].

Magnetic stimulation therapy could aid patients who don’t respond to antidepressants. Scientists from the University of Helsinki and Stanford University are refining techniques that may lead to personalized treatments in the future.

Not every patient with depression benefits from medication. Recent research highlights potential improvements in an alternative approach, transcranial magnetic stimulation (TMS), for treating depression. TMS is distinct from electroconvulsive therapy (ECT), another treatment option for depression.

Researchers from the University of Helsinki and Stanford University investigated which factors in targeting TMS influence the brain’s electrical responses. They examined the behavior of a specific electrophysiological marker. This marker could potentially be used as a biomarker in the future to measure the efficacy of TMS treatment and thus help target and tailor the therapy.