Detection of the first signal of its kind in the human brain! Detection of the first signal of its kind in the human brain!

Detection of the first signal of its kind in the human brain!

Detection of the first signal of its kind in the human brain!

Scientists have recently identified a unique form of cellular messaging that occurs in the human brain that has not been seen before.
Interestingly, this discovery hints that our brains may be more powerful units of computation than we realize.

In 2020, researchers from institutes in Germany and Greece reported a mechanism in the brain's outer cortical cells that produces a new 'stepping' signal on its own, one that could provide individual neurons with another way to perform their logical functions.

By measuring electrical activity in sections of tissue removed during surgery on epilepsy patients and analyzing their structure using fluorescence microscopy, neurologists have found that individual cells in the cerebral cortex use not only their usual sodium ions to "fire", but calcium as well.

This mixture of positively charged ions triggered previously unseen potential waves, referred to as dendritic calcium-mediated action potentials, or dCaAPs.

Brains - especially those of the human species - are often compared to computers. This analogy has its limitations, but at some levels the tasks perform in similar ways. They both use voltage to perform different operations. In computers this is in the form of a fairly simple flow of electrons through junctions called transistors.

In neurons, the signal is in the form of a wave of opening and closing channels that exchange charged particles such as sodium, chloride, and potassium. This pulse of flowing ions is called an action potential.

Instead of transistors, neurons chemically conduct these messages at the end of branches called dendrites.

“Dendrites are fundamental to understanding the brain because they are the core of what determines the computational power of single neurons,” Humboldt University neuroscientist Matthew Larcom told Walter Beckwith at the American Association for the Advancement of Science in January 2020. The dendrites are the traffic lights for our nervous system. If the action potential is great enough, it can travel to other nerves, which can block or transmit the message.

And these are the rationales of our brains - ripples of voltage that can be communicated collectively in two forms: either an AND message (if x and y are triggered, the message is passed on); or an OR message (if x and y are triggered, the message is passed).

Nowhere is it more complex than the dense, wrinkled outer part of the human central nervous system. cerebral cortex. The second and third deep layers are particularly thick, packed with branches that perform higher-order functions that we associate with sensation, thought, and motor control.

The researchers took a closer look at the tissue of these layers, attaching the cells to a device called a neurosomatic patch clamp to send energetic potentials up and down each neuron, and record their signals.

"There was a 'eureka' moment when we first saw the potential of dendritic action," Larcom said.

To ensure that any findings were not unique to people with epilepsy, they reviewed their results in a small number of samples taken from brain tumors.

While the team ran similar experiments on mice, the types of signals they observed buzzing through human cells were very different.

Importantly, when they dosed the cells with a sodium channel blocker called tetrodotoxin, the signal persisted.

In addition to the logical AND and OR functions, these individual neurons can function as "exclusive" OR (XOR) interrupts, which only allow a signal when another signal is classified in a certain way.

"Traditionally, the XOR operation was thought to require a network solution," the researchers wrote.

More work needs to be done to find out how dCaAPs behave across entire neurons, and in a living system. Not to mention if it was something human, or if similar mechanisms evolved elsewhere in the animal kingdom.

Technology is also looking to our nervous system for inspiration on how to develop better devices. 

This research was published in the journal Science.





Brain images 64 million times clearer than what current technology offers may lead to a cure for dementia!


Researchers have revealed the most detailed image ever captured of the brain - 64 million times sharper than current technology allows.
The image of a mouse brain was captured using a high-powered MRI machine with an unprecedented level of detail.

Scientists have yet to replicate the highly detailed scans on human brains, which in the future could help doctors detect diseases earlier and help patients survive longer. They hope that scanning the brains of mice will pave the way for breakthroughs in treating the development of neurodegenerative diseases such as Alzheimer's disease.

A team of researchers from North Carolina, Tennessee, Pennsylvania and Indiana used a high-energy magnetic resonance imaging (MRI) scanner that provides the sharpest and most detailed images, revealing the complexities of mouse brain organization and connectivity.

The scientists produced MRI scans that were 64 million times sharper than what can currently be achieved in hospitals.

While MRI scans are essential for diagnosing fatal conditions such as brain tumors, they cannot currently delve into the microscopic details.

After completing an MRI scan of the mouse brain in exquisite detail, the scientists produced another image using a method known as optical sheet microscopy. This allowed the team to visualize the internal structure and connections within the brain in detail with color technology.

Scans have so far only been performed on mice, but the scientists behind the innovation are optimistic that this technology could be integral to tracking age-related changes in human brains, which could lead to innovative new treatments.

The team was led by researchers at the Center for Microscopy at Duke University, and is the culmination of four decades of research.

The color scans show changes in brain connections with age. They also show how certain regions of the brain - such as a sub-region associated with memory - change more than the rest of the mouse brain.

The report detailing the findings of the surveys was published in the Proceedings of the National Academy of Sciences.

"We can start to look at neurodegenerative diseases in a completely different way," said Alan Johnson, lead author of the new paper. "MRI uses magnets and radio waves to produce scans." The scientists were able to produce a rainbow-coloured peek inside the neural networks of mice of different ages and genetic makeups using extremely powerful magnets, much stronger than those normally used in an MRI machine.

To help create the brain image, they used a high-performance computer equivalent of nearly 800 laptops all running simultaneously to image a single brain.

After completing the MRI scan, the scientists performed an optical paper microscopy on the sample of brain tissue, enabling them to classify specific groups of cells in the brain and monitor them for changes or progression in neurodegenerative disease over time.

The images were also able to capture how Alzheimer's disease breaks down neural networks.

The applications of high-energy MRI technology could be wide ranging, helping doctors to diagnose cancers and neurological diseases before it's too late.
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