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Circadian Rhythms Help Guide Waste From Brain

During wakeful periods, the glymphatic system diverts cerebrospinal fluid to lymph nodes in the neck. The CSF may act as a “fluid clock” that helps initiate the body’s infection-fighting capabilities during the day. Astrocytes in the suprachiasmatic nucleus may serve to control CSF through the central nervous system. Communication between astrocytes in different brain regions may optimize the glymphatic system’s function as we sleep.

neurosciencenews

Common Drugs Tied to Increased Risk of Cognitive Decline A class of drugs used for many conditions, including allergies, colds, high blood pressure and depression, may be associated with an increased risk of developing mild thinking and memory problems, particularly in people who have genetic risk factors for Alzheimer’s disease or markers of this condition, according to a study published in the September 2, 2020, online issue of Neurology. These types of drugs, called anticholinergic drugs, are used for motion sickness, urinary incontinence, overactive bladder, Parkinson’s disease and high blood pressure. There are approximately 100 such drugs in widespread use, with some requiring a prescription and many others that may be purchased over the counter.

neurosciencestuff

New Study Finds Unexpected Link Between Immune Cells and Male/Female Differences

Researchers at the University of Maryland School of Medicine (UMSOM) have made a surprising discovery: during fetal development, a particular immune cell seems to play a key role in determining the male or female characteristics of the brain.

“This a totally new discovery,” says Margaret McCarthy, PhD, professor and chairman of the UMSOM Department of Pharmacology. “Prior to this, we didn’t know that these cells played a role in this process at all.”

The study was published in the Journal of Neuroscience.

Prof. McCarthy and her colleagues studied immune cells known as mast cells, which originate in the bone marrow but are found on body surfaces such as the skin, mouth, nose and eyes. They are also found on the outside surface of the brain in a membrane known as the meninges. Mast cells are signaling molecules, and when activated, they release a range of molecules, including serotonin, histamine and other inflammatory substances. In general they act as triggers for other immune system cells to respond to an injury or threat to the body.

“Mast cells are basically a signaling system, they release these substances, which signal to other immune cells to come and help out,” says Prof. McCarthy.

At the same time, they also exist, in small numbers, in a specific area of the brain known as the preoptic area. The preoptic area contributes to the control of sexual motivation and parenting behavior, basic behaviors that occur in nearly all species. During development, between 10 and 70 mast cells exist in this area. This study found that in males there are more of the cells in this area than in females, typically about twice as many, and they are more actively releasing their signaling molecules, in particular histamine.

Surprisingly, the histamine released by the mast cells in males signals to another immune cell, the microglia, and instructs them to make prostaglandins, another inflammatory signaling molecule. In previous research, Prof. McCarthy’s lab has shown how prostaglandins induce the development of neural connections in the preoptic area.

In research on rats, Prof. McCarthy and her colleagues found this crucial development occurs in the first week of postnatal development, and plays a large role in determining differences between the male and female brains. She says the findings amazed her: “This one type of cell, and a very small number of these cells, is orchestrating this complex multicellular process to permanently change the circuitry of the brain to make it different in males and females.”

In many animals, including both rats and humans, certain regions of male and female brains are quite different. Imaging studies in humans suggest that females tend to have more cross-hemisphere connections, while males tend to have more connections within each hemisphere.

There are also differences in the size of certain parts of the brain. Certain parts of the hypothalamus are larger in men than women. This divergence may play a role in determining sexual orientation. In gay men, this hypothalamic region is smaller than in heterosexual men; it is typically the same size as in heterosexual women.

On the cellular level male and female brains are also sometimes different. Males tend to have more dense synaptic connections in the preoptic area, while in other areas, females have more dense synaptic connections.

Prof. McCarthy has focused much of her work on the neuroscience of sex differences. In previous research she found sex and gender differences in levels of a protein associated with language acquisition and development. This finding may be associated with higher levels of communication among females in some species.

In previous research, she had found that another kind of immune cell known as microglia appear to play a role in masculinization, in part through their production of prostaglandins, a neurochemical normally associated with illness. In recent years, scientists have increasingly realized that the immune system is integral to the development of the brain;

Prof. McCarthy and her colleagues are now doing additional research on the links between the immune system and brain sex differences. They will next focus on the role of histamine, one of the chemicals released by mast cells, to discover more about precisely what role it plays in the process.

“This work provides fascinating new insight into how male and female brains develop differently,” said E. Albert Reece, MD, PhD, MBA, Executive Vice President for Medical Affairs at the University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. “Prof. McCarthy has spent years working in this important area, and this is just the latest discovery in a remarkable career.”

toxicscientist

Super interesting, as this has been questioned for years.

- At what embryotic stage is the gender determined during fetal development, but most importantly how do the chromosomes define this?

currentsinbiology

'Really spectacular finding' may shed light on ancient evolution of digestive systems

A scientist has stumbled upon a creature with a “transient anus” that appears only when it is needed, before vanishing completely.

The warty comb jelly, or sea walnut, looks a lot like a jellyfish, but the new finding reveals it may represent a critical stage in evolutionary history.

While regular jellyfish eat food and release waste out of the same opening, these creatures have an anal pore that ejects digested food once the gut has filled up.

Fun fact of the day: We share approximately 60% of our dna with bananas!

mindblowingscience

Black holes have been mysterious and elusive — until now. Astronomers using the Event Horizon Telescope (EHT) have, for the first time, photographed one.

“We’ve now seen the unseeable,” said Avery Broderick, a physicist at the University of Waterloo and the Perimeter Institute who was part of the international EHT research team. “Black holes are made real — they’re not just the scribblings on theorists’ chalkboards anymore, but they really are out there in the night.”

The image, which shows an orange ring around a round, black silhouette, is of the black hole at the centre of Messier 87 (M87), a galaxy 50 million light-years from Earth. This black hole is one of the most massive known: it’s six billion times more massive than our sun.

Black holes are so dense and have such strong gravity that anything that crosses their threshold — known as the event horizon — gets pulled into them, never to return. That includes both matter and light, making them black and invisible — and therefore very difficult to see and photograph.

An international team of more than 200 people spent more than a decade working to capture the image released today.

curiosityistheleastofmyproblems

Methods of surgery to correct strabismus, a condition when the eyes are not aligned with each other.

Is String Theory the final solution for all of physic’s questions or an overhyped dead end? This video was realised with the help of Dr. Alessandro Sfondrini...

webeducationsciences

General theory of relativity by dirac pdf General theory of relativity by dirac pdf : Pages 70 By : BY P. A. M. DIRAC Download

Great book by Dirac

hilarioushumorfromouterspace

pathcend

Memories of music cannot be lost to Alzheimer’s and dementia

If you’re especially into a piece of music, your brain does something called Autonomous Sensory Meridian Response (ASMR), which feels to you like a tingling in your brain or scalp. It’s nature’s own little “buzz”, a natural reward, that is described by some as a “head orgasm”. Some even think that it explains why people go to church, for example, “feeling the Lord move through you”, but that’s another article for another time.

Turns out that ASMR is pretty special. According to a recently published study in The Journal of Prevention of Alzheimer’s Disease, the part of your brain responsible for ASMR doesn’t get lost to Alzheimer’s. Alzheimer’s tends to put people into layers of confusion, and the study confirms that music can sometimes actually lift people out of the Alzheimer'shaze and bring them back to (at least a semblance of) normality… if only for a short while. ASMR is powerful stuff!

Read the full article at Big Think

startswithabang

What Was It Like When Our Solar System First Formed?

“Over the past few years, we’ve finally been able to observe solar systems in these very early stages of formation, finding central stars and proto-stars shrouded by gas, dust, and protoplanetary disks with gaps in them. These are the seeds of what will become giant and rocky planets, leading to full-on solar systems like our own. Although most of the stars that form — including, very likely our own — will have formed amidst thousands of others in massive star clusters, there are a few outliers that form in relative isolation.

Although the history of the Universe may subsequently separate us from all of our stellar and planetary siblings from the nebula that they formed in billions of years ago, scattering them across the galaxy, our shared history remains. Whenever we find a star with approximately the same age and abundance of heavy elements as our Sun, we cannot help but wonder: is this one of our long-lost siblings? The galaxy is likely full of them.”

It took a whopping 9.2 billion years of cosmic evolution for the Universe to give rise to the very beginning of our Solar System; our Sun and planets didn’t form until 2/3rds of the time since the Big Bang had passed. In order to get there, we needed to form the right ingredients for life, rocky planets, and the chemistry we need. But when it happened to us, we weren’t alone. It likely happened exactly the same way for thousands of other stars at once, and continues to happen even up through the present day.

Are we alone in the Universe? The cosmic story that brought us to existence seems to be a story that’s universal. Here’s a key step in how we got here.

I can say I’m guilty of this.

neurosciencenews

Researchers Rejuvenate Stem Cells In the Aging Brain: Mouse Study

Researchers have been able to rejuvenate stem cells in the brain of aging mice.

The revitalised stem cells improve the regeneration of injured or diseased areas in the brain of old mice. The researchers expect that their approach will provide fresh impetus in regenerative medicine and facilitate the development of stem cell therapies.

The research is in Cell. (full access paywall)

oddnumberone

Planet Rotation Periods & Axial Tilts

mcphysics

spinny boys

mindblowingscience

New 8-Letter DNA Rewrites the Genetic Code | SciShow News

Scientists have successfully created synthetic DNA with twice as many base pairs as normal, with potential implications in medicine, data storage, and even understanding how life could evolve elsewhere in the universe.

Hosted by: Stefan Chin

nationalsciencefoundation

We’re back with 4 Awesome Discoveries You Probably Didn’t Hear About This Week, all with funding from NSF: bit.ly/2Hbbhei ✅ Stretchy strength ✅ Table for crime scenes ✅ Snake buckling behavior ✅ Rewriting the history of oxygen Research by WHOI, Cornell University, Arizona State University, Florida State University, University of Waterloo, North Carolina State University and Georgia Tech

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