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Jul 9, 2022

Two heads are better than one: Gene expression reveals molecular mechanisms underlying evolution of cerebral cortex

Posted by in categories: evolution, genetics, neuroscience

Dramatic expansion of the human cerebral cortex, over the course of evolution, accommodated new areas for specialized cognitive function, including language. Understanding the genetic mechanisms underlying these changes, however, remains a challenge to neuroscientists.

A team of researchers in Japan has now elucidated the mechanisms of cortical evolution. They used molecular techniques to compare the in mouse and monkey brains.

Using the technique called in situ hybridization to visualize the distribution of mRNA transcripts, Okano, Shimogori and their colleagues examined the expression patterns of genes that are known to regulate development of the . They compared these patterns to those of the same genes in the brain of the common marmoset. They found that most of the genes had similar expression patterns in mice and marmosets, but that some had strikingly different patterns between the two species. Notably, some areas of the visual and prefrontal showed expression patterns that were unique to marmosets.

Jul 9, 2022

The beginnings of the thinking brain

Posted by in categories: genetics, neuroscience

Oxford researchers have identified the very first neurons in the human cerebral cortex, the part of the brain that sets us apart from all other animals.

Dr Irina Bystron and colleagues from the Department of Physiology, Anatomy and Genetics at the University of Oxford, together with Professor Pasko Rakic, a leading neuroscientist at Yale University, describe for the first time in Nature Neuroscience the very earliest nerve cells in the part of the developing human brain that becomes the cerebral cortex.

The cerebral cortex is largely responsible for human cognition, playing an essential role in perception, memory, thought, language, mental ability, intellect and consciousness. It is also responsible for our voluntary actions. As adults our cerebral cortex accounts for 40 per cent of the brain’s weight and is composed of about 20 billion neurons. The new findings show that its first neurons are in place much earlier than previously thought – approximately 31 days after fertilization, when the entire embryo is only about 4 mm long and shaped a bit like a comma, before the development of arms, legs or eyes.

Jul 9, 2022

Biochemists use enzymes to change how brain cells communicate with each other

Posted by in categories: biological, chemistry, neuroscience

As you’re reading this sentence, the cells in your brain, called neurons, are sending rapid-fire electrical signals between each other, transmitting information. They’re doing so via tiny, specialized junctions between them called synapses.

There are many different types of that form between neurons, including “excitatory” or “inhibitory,” and the exact mechanisms by which these structures are generated remain unclear to scientists. A Colorado State University biochemistry lab has uncovered a major insight into this question by showing that the types of chemicals released from synapses ultimately guide which kinds of synapses form between neurons.

Soham Chanda, assistant professor in the Department of Biochemistry and Molecular Biology, led the study published in Nature Communications that demonstrates the possibility of changing the identity of synapses between neurons, both in vitro and in vivo, through enzymatic means. The other senior scientists who contributed to the project were Thomas Südhof of Stanford University and Matthew Xu-Friedman of the University at Buffalo.

Jul 9, 2022

The omicron subvariant now dominating the US is ‘the worst version of the virus that we’ve seen’

Posted by in categories: biotech/medical, health

New immune-evading Omicron subvariant BA.5 is now dominant in the U.S.—and previous heavy hitter “stealth Omicron” is now a shadow of its former self, according to federal health data released Tuesday.

BA.5 is estimated to have caused nearly 54% of COVID infections in the U.S. last week, according to data from the U.S. Centers for Disease Control and Prevention. Along with twin variant BA.4, it swept South Africa this spring thanks to its ability to evade immunity from both prior infection and vaccination.

The week before that, the two variants combined made up slightly more than half of U.S. cases. But last week, BA.5 accomplished the same feat alone, without the help of BA.4, which came in third at 16.5%.

Jul 9, 2022

China’s Mars probe has photographed the entire red planet

Posted by in category: space

After more than a year on the surface of Mars, China’s Tianwen-1 probe has taken images covering the entire red planet, the country’s space agency announced Wednesday.

Tianwen-1, which means “quest for heavenly truth,” was launched in 2020 and landed on Mars last May, when the Zhurong rover on board started its mission of patrolling and exploring the planet while the orbiter spun overhead.

In a statement, China’s National Space Agency (CNSA) said the probe has now completed all its assigned tasks, including taking medium-resolution images covering the entire planet.

Jul 8, 2022

How Dopamine Plays a Key Role in Consciousness

Posted by in category: neuroscience

Summary: Study reveals how dopamine may have a central role in maintaining our consciousness.

Source: The Conversation.

Consciousness is arguably the most important scientific topic there is. Without consciousness, there would after all be no science. But while we all know what it is like to be conscious – meaning that we have personal awareness and respond to the world around us – it has turned out to be near impossible to explain exactly how it arises from the hardware of the brain. This is dubbed the “hard” problem of consciousness.

Jul 8, 2022

Miniature, Implantable Nerve Coolers for Targeted Pain Relief

Posted by in category: biotech/medical

Summary: Researchers have developed a new implantable device that can “cool” nerves and provide on-demand pain relief for those suffering from neuropathic or chronic pain.

Source: AAAS

An implantable device designed to “cool” nerves can provide targeted, on-demand pain relief, researchers report. When tested on rats with neuropathic pain, the device produced highly localized cooling.

Jul 8, 2022

Awareness Without a Sense of Self

Posted by in category: neuroscience

Summary: People who practice meditation often report feeling “pure awareness” in which they say they experience consciousness itself. The state encompasses specific sensations and non-specific feelings, thoughts, and perceptions. Researchers say their findings will help explain “pure consciousness,” and work to generate a prototypical minimal model for human conscious perception.

Source: Johannes Gutenberg University Mainz.

In the context of meditation practice, meditators can experience a state of “pure awareness” or “pure consciousness”, in which they perceive consciousness itself. This state can be experienced in various ways, but evidently incorporates specific sensations as well as non-specific accompanying perceptions, feelings, and thoughts.

Jul 8, 2022

All About Diamonds & Graphene

Posted by in category: materials

All About Graphene — YouTube


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Jul 8, 2022

Google Engineer on His Sentient AI Claim

Posted by in category: robotics/AI

Google Engineer Blake Lemoine joins Emily Chang to talk about some of the experiments he conducted that lead him to think that LaMDA was a sentient AI, and to explain why he is now on administrative leave.