A unique brain signal may be the key to human intelligence

Though progress is being made, our brains remain organs of many mysteries. Among these are the exact workings of neurons, with some 86 billion of them in the human brain. Neurons are interconnected in complicated, labyrinthine networks across which they exchange information in the form of electrical signals. We know that signals exit an individual neuron through a fiber called an axon, and also that signals are received by each neuron through input fibers called dendrites.

Understanding the electrical capabilities of dendrites in particular — which, after all, may be receiving signals from countless other neurons at any given moment — is fundamental to deciphering neurons’ communication. It may surprise you to learn, though, that much of everything we assume about human neurons is based on observations made of rodent dendrites — there’s just not a lot of fresh, still-functional human brain tissue available for thorough examination.

For a new study published January 3 in the journal Science, however, scientists got a rare chance to explore some neurons from the outer layer of human brains, and they discovered startling dendrite behaviors that may be unique to humans, and may even help explain how our billions of neurons process the massive amount of information they exchange.

A PUZZLE, SOLVED?

Electrical signals weaken with distance, and that poses a riddle to those seeking to understand the human brain: Human dendrites are known to be about twice as long as rodent dendrites, which means that a signal traversing a human dendrite could be much weaker arriving at its destination than one traveling a rodent’s much shorter dendrite. Says paper co-author biologist Matthew Larkum of Humboldt University in Berlin speaking to LiveScience, “If there was no change in the electrical properties between rodents and people, then that would mean that, in the humans, the same synaptic inputs would be quite a bit less powerful.” Chalk up another strike against the value of animal-based human research. The only way this would not be true is if the signals being exchanged in our brains are not the same as those in a rodent. This is exactly what the study’s authors found.

The researchers worked with brain tissue sliced for therapeutic reasons from the brains of tumor and epilepsy patients. Neurons were resected from the disproportionately thick layers 2 and 3 of the cerebral cortex, a feature special to humans. In these layers reside incredibly dense neuronal networks.

Without blood-borne oxygen, though, such cells only last only for about two days, so Larkum’s lab had no choice but to work around the clock during that period to get the most information from the samples. “You get the tissue very infrequently, so you’ve just got to work with what’s in front of you,” says Larkum. The team made holes in dendrites into which they could insert glass pipettes. Through these, they sent ions to stimulate the dendrites, allowing the scientists to observe their electrical behavior.

In rodents, two type of electrical spikes have been observed in dendrites: a short, one-millisecond spike with the introduction of sodium, and spikes that last 50- to 100-times longer in response to calcium.

In the human dendrites, one type of behavior was observed: super-short spikes occurring in rapid succession, one after the other. This suggests to the researchers that human neurons are “distinctly more excitable ” than rodent neurons, allowing them to successfully traverse our longer dendrites.

In addition, the human neuronal spikes — though they behaved somewhat like rodent spikes prompted by the introduction of sodium — were found to be generated by calcium, essentially the opposite of rodents.

AN EVEN BIGGER SURPRISE

The study also reports a second major finding. Looking to better understand how the brain utilizes these spikes, the team programmed computer models based on their findings. (The brains slices they’d examined could not, of course, be put back together and switched on somehow.)

The scientists constructed virtual neuronal networks, each of whose neurons could could be stimulated at thousands of points along its dendrites, to see how each handled so many input signals. Previous, non-human, research has suggested that neurons add these inputs together, holding onto them until the number of excitatory input signals exceeds the number of inhibitory signals, at which point the neuron fires the sum of them from its axon out into the network.

However, this isn’t what Larkum’s team observed in their model. Neurons’ output was inverse to their inputs: The more excitatory signals they received, the less likely they were to fire off. Each had a seeming “sweet spot” when it came to input strength.

What the researchers believe is going on is that dendrites and neurons may be smarter than previously suspected, processing input information as it arrives. Mayank Mehta of UC Los Angeles, who’s not involved in the research, tells LiveScience, “It doesn’t look that the cell is just adding things up — it’s also throwing things away.” This could mean each neuron is assessing the value of each signal to the network and discarding “noise.” It may also be that different neurons are optimized for different signals and thus tasks.

Much in the way that octopuses distribute decision-making across a decentralized nervous system, the implication of the new research is that, at least in humans, it’s not just the neuronal network that’s smart, it’s all of the individual neurons it contains. This would constitute exactly the kind of computational super-charging one would hope to find somewhere in the amazing human brain.

Link Original:https://bigthink.com/neuropsych/human-neuron-signals/#Echobox=1629474922


A desidratação compromete o funcionamento de todo o organismo.

Ingerir líquidos precisa ser um hábito frequente, uma vez que nos desidratamos diariamente através da respiração, do suor, da urina e das fezes. Manter o corpo hidratado ajuda nas atividades das células, na digestão, no funcionamento dos rins, regulação da pressão arterial, na atividade cerebral e na aparência da pele.

A função da água no corpo é transportar e distribuir vitaminas, minerais, glicose, oxigênio e outros nutrientes para as células. Mas, se você não é muito do tipo que gosta bem beber água, existem alimentos, produtos e outras bebidas que ajudam você a se manter melhor hidratado.

A combinação ideal para manter o corpo hidratado é consumir líquidos ricos em eletrólitos e minerais que auxiliam a absorção dos nutrientes pelas células, como cálcio, magnésio, potássio, sódio, manganês, cromo, fósforo e cloro.

Link Original: #essentialnutrition#desidratacao#agua


The secret to regeneration? Scientists say it lies in the axolotl genome.

Few creatures have captured the attention of both the general public and scientists as thoroughly as a peculiar-looking salamander known as the axolotl. Native only to Lake Xochimilco, south of Mexico City, axolotls are less and less frequently found in the wild. However, they are relatively abundant in captivity, with pet enthusiasts raising them due to their alien features, such as the striking, fringy crown they wear on their heads. Researchers also keep a large supply of axolotl in captivity due to the many unique properties that make them attractive subjects of study.

Perhaps the most notable and potentially useful of these characteristics is the axolotl’s uncanny ability to regenerate. Unlike humans and other animals, axolotls don’t heal large wounds with the fibrous tissue that composes scars. Instead, they simply regrow their injured part. 

«It regenerates almost anything after almost any injury that doesn’t kill it,» said Yale researcher Parker Flowers in a statement. This capability is remarkably robust, even for salamanders. Where regular salamanders are known to regrow lost limbs, axolotls have been observed regenerating ovaries, lung tissues, eyes, and even parts of the brain and spinal cord.

Obviously, figuring out how these alien-looking salamanders manage this magic trick is of great interest to researchers. Doing so could reveal a method for providing humans with a similar regenerative capability. But identifying the genes involved in this process has been tricky — the axolotl has a genome 10 times larger than that of a human’s, making it the largest animal genome sequenced to date.

Fortunately, Flowers and colleagues recently discovered a means of more easily navigating this massive genome and, in the process, identified two genes involved in the axolotl’s remarkable regenerative capacity.

A new role for two genes

We’ve understood the basic process of regeneration in axolotls for a while now. After a limb is severed, for instance, blood cells clot at the site, and skin cells start to divide and cover the exposed wound. Then, nearby cells begin to travel to the site and congregate in a blob called the blastema. The blastema then begins to differentiate into the cells needed to grow the relevant body part and grow outward according to the appropriate limb structure, resulting in a new limb identical to its severed predecessor.

But identifying which genes code for this process and what mechanisms guide its actions is less clear. Building off of previous work using CRISPR/Cas9, Flowers and colleagues were able to imprint regenerated cells with a kind of genetic barcode that enabled them to trace the cells back to their governing genes. In this way, they were able to identify and track 25 genes suspected to be involved in the regeneration process. From these 25, they identified two genes related to the axolotls’ tail regeneration; specifically, the catalase and fetub genes.

Although the researchers stressed that many more genes were likely driving this complicated process, the finding does have important implications for human beings — namely that humans also possess similar genes to the two identified in this study. Despite sharing similar genes, the same gene can do very different work across species and within a single animal. The human equivalent gene FETUB, for example, produces proteins that regulate bone resorption, regulates insulin and hepatocyte growth factor receptors, responds to inflammation, and more. In the axolotl, it appears that regulating the regenerative process is another duty.

Since humans possess the same genes that enable axolotls to regenerate, researchers are optimistic that one day we will be able to speed up wound healing or even to completely replicate the axolotl’s incredible ability to regenerate organs and limbs. With continued research such as this, it’s only a matter of time until this strange salamander gives ups its secrets.

Link Original: https://bigthink.com/surprising-science/axolotl-regeneration?rebelltitem=1#rebelltitem1



Frequent cannabis use by young people linked to decline in IQ


A study has found that adolescents who frequently use cannabis may experience a decline in Intelligence Quotient (IQ) over time. The findings of the research provide further insight into the harmful neurological and cognitive effects of frequent cannabis use on young people.

The paper, led by researchers at RCSI University of Medicine and Health Sciences, is published in Psychological Medicine.

The results revealed that there were declines of approximately 2 IQ points over time in those who use cannabis frequently compared to those who didn’t use cannabis. Further analysis suggested that this decline in IQ points was primarily related to reduction in verbal IQ.

The research involved systematic review and statistical analysis on seven longitudinal studies involving 808 young people who used cannabis at least weekly for a minimum of 6 months and 5308 young people who did not use cannabis. In order to be included in the analysis each study had to have a baseline IQ score prior to starting cannabis use and another IQ score at follow-up. The young people were followed up until age 18 on average although one study followed the young people until age 38.

«Previous research tells us that young people who use cannabis frequently have worse outcomes in life than their peers and are at increased risk for serious mental illnesses like schizophrenia. Loss of IQ points early in life could have significant effects on performance in school and college and later employment prospects,» commented senior author on the paper Professor Mary Cannon, Professor of Psychiatric Epidemiology and Youth Mental Health, RCSI.

«Cannabis use during youth is of great concern as the developing brain may be particularly susceptible to harm during this period. The findings of this study help us to further understand this important public health issue,» said Dr Emmet Power, Clinical Research Fellow at RCSI and first author on the study.

The study was carried out by researchers from the Department of Psychiatry, RCSI and Beaumont Hospital, Dublin (Prof Mary Cannon, Dr Emmet Power, Sophie Sabherwal, Dr Colm Healy, Dr Aisling O’Neill and Professor David Cotter).

The research was funded by a YouLead Collaborative Doctoral Award from the Health Research Board (Ireland) and a European Research Council Consolidator Award.

Link Original: https://www.sciencedaily.com/releases/2021/01/210128134755.htm?fbclid=IwAR1Qrhejc9x-9uGRofHtmX8YX4E6qukoS7LIVMK8iwYvcaitU_RVCH4G_xo


‘Ichigo-Ichie’, haz de cada instante algo único

Descubrimos el arte japonés de compartir momentos inolvidables en el libro ‘Ichigo Ichie. Haz de cada instante algo único’


Lo que va a suceder aquí no se repetirá nunca más. ¿Lo habías pensado alguna vez? ¿Habías tenido en cuenta que cada momento es irrepetible, por aburrido o maravilloso que sea? En la cultura tradicional japonesa lo llaman Ichigo-Ichie, un encuentro, una oportunidad

Y aunque sea una metáfora de vida, el término se creó en la ceremonia del té, donde el maestro pedía a los participantes su máxima y plena atención.Una ceremonia donde se cultivan los cinco sentidos: cómo sabe el té, cuál es su aroma, cómo son los utensilios y admirar su belleza, tocarlos y sentir cada sorbo como algo especial y aprender a escuchar todo lo que les rodea en esa ceremonia; que suele realizarse en casas en mitad del bosque.

Puedes imaginar entonces, el sonido de los árboles, de los pájaros cantando y del chorro de agua que cae en una de las cuidadas tazas de cerámica japonesas. Eso es Ichigo-Ichie.

Leer Más

UV-LED disinfection of Coronavirus: Wavelength effect

LED lights found to kill coronavirus: Global first in fight against COVID-19

NEWS / CORONAVIRUS

TAU finding suggests technology can be installed in air conditioning, vacuum, and water systems

December 14th, 2020 SUPPORT THIS RESEARCH

Researchers from Tel Aviv University (TAU) have proven that the coronavirus can be killed efficiently, quickly, and cheaply using ultraviolet (UV) light-emitting diodes (UV-LEDs). They believe that the UV-LED technology will soon be available for private and commercial use.

Leer Más

Common class of drugs linked to increased risk of Alzheimer’s disease

A team of scientists, led by researchers at University of California San Diego School of Medicine, report that a class of drugs used for a broad array of conditions, from allergies and colds to hypertension and urinary incontinence, may be associated with an increased risk of cognitive decline, particularly in older adults at greater risk for Alzheimer’s disease (AD).

Leer Más


Alimentos ultraprocessados favorecem envelhecimento biológico

Estudo com mais de 800 pessoas sugere que uma dieta ruim pode fazer com que as células envelheçam de forma mais rápida

Os alimentos industrializados são práticos, mas, segundo pesquisadores, favorecem o envelhecimento biológico se consumidos com frequência.

O estudo, que possibilitou medir um marcador do envelhecimento biológico (o comprimento de componentes genéticos chamados telômeros) em 886 espanhóis de mais de 55 anos, levando em conta o seu consumo diário de alimentos ultraprocessados, sugere que uma dieta ruim pode fazer com que as células envelheçam de forma mais rápida.

Leer Más


95% of U.S. baby foods contain toxic metals. Here’s what parents should know.

«On the spectrum from worry to action, parents can choose to act,» a new report states.

  • A new investigation tested 168 baby food products for arsenic, lead, cadmium and mercury, all of which are toxic metals that can damage brain development in infants.
  • Nearly all of the foods tested contained at least one of the metals, and 1 in 4 contained all four metals.
  • The authors of the report recommended five steps for finding alternative baby foods with less toxins.

Almost all of the baby food products tested in a new investigation contained traces of toxic heavy metals that can damage brain development in infants.

Leer Más