Research strongly suggests that sleep, which constitutes about a third of our lives, is crucial for learning and forming long-term memories. But exactly how such memory is formed is not well understood and remains, despite considerable research, a central question of inquiry in neuroscience.
Neuroscientists at the University of California, Riverside report this week in the Journal of Neuroscience that they now may have an answer to this question. Their study provides for the first time a mechanistic explanation for how deep sleep (also called slow-wave sleep) may be promoting the consolidation of recent memories.
The human brain has a prodigious demand for energy — 20 to 30% of the body’s energy budget. In the course of normal aging, in people with neurodegenerative diseases or mental disorders, or in periods of physiological stress, the supply of sugars to the brain may be reduced. This leads to a reduction in the brain’s energy reserves, which in turn can lead to cognitive decline and loss of memory.
But new research on mice shows that the brain’s energy reserves can be increased with a daily dose of pyruvate, a small energy-rich molecule that sits at the hub of most of the energy pathways inside the cell. These results need to be replicated in human subjects, but could ultimately lead to clinical applications.
Posted in Aging, Brains
Tagged Aging, brains
What makes one person more resilient to stress than another? How do some people seemingly take even extreme stress in stride while others succumb to depression or anxiety disorders when faced with trauma or tragedy? Might differences in brain structure or function explain it?
These are questions that have been tackled by social scientists for decades, resulting in a fairly comprehensive description of the kinds of emotional and behavioral characteristics that tend to describe a “stress-resilient” person–things like optimism, a strong social support system, an ability to find purpose in life, or a grounding in faith or spirituality. A “glass-half-full” kind of person.
More recently, neuroscience has tackled the question of resilience, with the goal of understanding what underlying neurobiological mechanisms might contribute to resilience in humans so that more targeted, more potent interventions can be developed. While treatment breakthroughs have been elusive, recent work has begun to shed new light on the resilient brain.
Why do we spend a third of our life asleep? The answer seems obvious: To recover from the “fatigue” of being awake, to be ready for another day of challenges, good or bad. All of us have experienced the consequences of a sleepless night: everything requires more effort; we lack energy and motivation and feel groggy, irritable, and snappish.
But there is strong, objective proof that, far from being just such a “time filler,” sleep serves an active, essential function. We know that all animal species that have been carefully studied sleep, with no exception. If sleep were not essential, one would expect that some would have evolved to do without it, since time spent asleep reduces time spent foraging, reproducing, or monitoring the environment. Moreover, being asleep puts an animal in a potentially dangerous situation, because it reduces the ability to promptly respond to stimuli that signal threat. Thus, sleep makes little sense, from an evolutionary point of view, unless it provides enough essential benefits to overcome its inherent risks.
Posted in Brains, Sleep
Tagged brains, sleep
Recall your favorite memory: the big game you won; the moment you first saw your child’s face; the day you realized you had fallen in love. It’s not a single memory, though, is it? Reconstructing it, you remember the smells, the colors, the funny thing some other person said, and the way it all made you feel.
Your brain’s ability to collect, connect, and create mosaics from these milliseconds-long impressions is the basis of every memory. By extension, it is the basis of you. This isn’t just metaphysical poetics. Every sensory experience triggers changes in the molecules of your neurons, reshaping the way they connect to one another. That means your brain is literally made of memories, and memories constantly remake your brain. This framework for memory dates back decades. And a sprawling new review published today in Neuron adds an even finer point: Memory exists because your brain’s molecules, cells, and synapses can tell time.
Knowing what you should fear, and quickly recognizing the biological changes in your body that indicate fear, can save your life. This critical task is processed by a small almond-shaped structure, the amygdala, which lies deep within the bottom of the brain, not far from your ears. The amygdala receives information from many brain regions, your internal organs, and external sensory systems, such as your eyes and ears. The amygdala integrates this information with various internal drives, such as whether you are hungry or thirsty or in pain; it then assigns a level of emotional significance to whatever is going on.
For example, when the amygdala becomes aware that you are alone and hearing unfamiliar sounds in the dark, it initiates a fear response, such as panic or anxiety. It then activates the appropriate body systems, the release of hormones, and specific behaviors to respond to the (real or imagined) threat.
Posted in Brains, Fear
Tagged brains, fear
According to a NeuroReport study, children’s sensitivity to the rhythmic properties of language emerges in-utero. Researchers discovered changes in fetal heart rate when exposed to different languages, suggesting babies tend to ‘tune in’ to the language they are going to acquire before they are born. A month before they are born, fetuses carried by American mothers-to-be can distinguish between someone speaking to them in English and Japanese.
Using non-invasive sensing technology from the University of Kansas Medical Center for the first time for this purpose, a group of researchers from KU’s Department of Linguistics has shown this in-utero language discrimination. Their study published in the journal NeuroReport has implications for fetal research in other fields, the lead author says.
Researchers shed new light on how DHA, a key essential Omega-3 fatty acid, could help promote cell survival and contribute to treating Alzheimer’s, Parkinson’s disease and stoke. Understanding how dietary essential fatty acids work may lead to effective treatments for diseases and conditions such as stroke, Alzheimer’s disease, age-related macular degeneration, Parkinson’s disease and other retinal and neurodegenerative diseases. The key is to be able to intervene during the early stages of the disease.
Posted in Omega 3
Tagged Omega 3
Two commonly used drugs can repair damage caused by alcohol in utero. Researchers from Northwestern University revealed that, with the aid of two drugs, it may be possible to repair neurological damage caused as a result of prenatal alcohol exposure. The study reports both drugs help normalize genes that control DNA methyl transferase1 expression, an enzyme critical for brain development. Two commonly used drugs erased the learning and memory deficits caused by fetal alcohol exposure when the drugs were given after birth, thus potentially identifying a treatment for the disorder, reports a new Northwestern Medicine study.
A new study from the University of Exeter adds to growing evidence that embarking on daily challenging puzzles can help protect brain function later in life. Researchers report older people who complete a daily crossword have brain function equivalent to people ten years their junior when it comes to grammatical reasoning and short term memory accuracy. The more regularly people report doing word puzzles such as crosswords, the better their brain function in later life, a large-scale and robust online trial has found. Experts at the University of Exeter Medical School and Kings College London analyzed data from more than 17,000 healthy people aged 50 and over, submitted in an online trial. In research presented at the Alzheimer’s Association International Conference (AAIC) 2017, the team asked participants how frequently they played word puzzles such as crosswords.