Molecule Of The Day: Limonene

How Do Antidepressants Work? (Video)

Your brain is a network of billions of neurones, all somehow connected to each other. At this very second, millions of impulses are being transmitted through these connections carrying information about what you can see and hear, as well as your emotional state. It’s an incredibly complex system but sometimes things go wrong. Despite extensive research, we are still not certain on the biology that underlies mental illnesses- including depression. However, we have come pretty far in developing effective treatments. 

Happy Valentine’s Day! Hope everybody gets their share of dopamine and oxytocin today. #lovefeelings #scientificliteracy #braininlove #brainfeels

Marrow Christmas and a Happy New Smear!

A very seasonal smear made from red marrow extracted from the iliac crest of a donor’s pelvis prior to transplantation.

Happy Holidays everyone

i♡histo

The image amazingly captures a single moment in time during the development of thousands of red and white blood cells.

Many of the small cells that are visible, like the ones forming the snowman’s carrot nose, do not have a nucleus. These are brand new erythrocytes (red blood cells) that are ready to exit the bone and enter the blood stream.

The other, slightly larger cells that have nuclei, like the snowman’s eyes and his top button, are either precursors to these erythrocytes (they will mature and lose their nucleus) or are precursors to the other blood cells in our body, the leukocytes (white blood cells): lymphocytes, monocytes, neutrophils, eosinophils and basophils.

In addition, the bone marrow is home to the cells that form platelets. These are huge multinucleated cells aptly named megakaryocytes - perhaps the cell at the bottom right.

It is possible to identify each mature cell and its precursor based upon its morphology and staining at higher magnification. High or low levels of these cells can indicate disease or cancers of the blood.

New insights into the molecular basis of memory

Scientists from the German Center for Neurodegenerative Diseases (DZNE) in Göttingen and Munich have shed new light on the molecular basis of memory. Their study confirms that the formation of memories is accompanied by an altered activity of specific genes. In addition, they found an unprecedented amount of evidence that supports the hypothesis that chemical labels on the backbone of the DNA (so-called DNA methylation) may be the molecular basis of long-term memory. These findings are reported in “Nature Neuroscience”.

The brain still harbours many unknowns. Basically, it is assumed that it stores experiences by altering the connections between brain cells. This ability to adapt – which is also called “plasticity” – provides the basis for memory and learning, which is the ability to draw conclusions from memories. On a molecular scale these changes are mediated by modifications of expression of specific genes that as required strengthen or weaken the connections between the brain cells.

In the current study, a research team led by Dr. Stefan Bonn and Prof. André Fischer from Göttingen, joined forces with colleagues from the DZNE’s Munich site, to examine how the activity of such genes is regulated. The scientists stimulated long-term memory in mice, by training the animals to recognise a specific test environment. Based on tissue samples, the researchers were able to discern to what extent this learning task triggered changes in the activity of the genes in the mice’s brain cells. Their focus was directed on so-called epigenetic modifications. These modifications involve the DNA and DNA associated proteins.

Epigenetic modifications

“The cell makes use of various mechanisms in order to turn genes on or off, without altering the DNA sequence itself. It’s called ‘epigenetics’,” explains Dr. Magali Hennion, a staff member of the research group of Stefan Bonn.

In principle, gene regulation can happen through methylation, whereby the backbone of the DNA is chemically labeled at specific sites. Changes in the proteins called histones that are packaging the DNA may also occur.

Hennion: “Research on epigenetic changes that are related to memory processes is still at an early stage. We look at such features, not only for the purpose of a better understanding of how memory works. We also look for potential targets for drugs that may counteract memory decline. Ultimately, our research is about therapies against Alzheimer’s and similar brain diseases.“

A code for memory contents?

In the current study the researchers found modifications, both of the histones as well as of the methylation of the DNA. However, histone modifications had little effect on the activity of genes involved in neuroplasticity. Furthermore, Bonn and his colleagues not only discovered epigenetic modifications in nerve cells, but also in non-neuronal cells of the brain.

“The relevance of non-neuronal cells for memory, is an interesting topic that we will continue to pursue“, says André Fischer, site speaker for the DZNE in Göttingen and professor at the University Medical Center Göttingen (UMG). “Furthermore, our observations suggest that neuroplasticity is to a large extent regulated by DNA methylation. Although this is not a new hypothesis, our study provides an unprecedented amount of supporting evidence for this. Thus, methylation may indeed be an important molecular constituent of long-term memory. In such a case, methylation could be a sort of code for memory content and a potential target for therapies against Alzheimer’s disease. This is an aspect that we specifically want to focus on, in further studies.”

Physicists Have Created a New Form of Hydrogen

The most abundant element in the Universe just got interesting.

As the element that makes up 75 percent of all the mass in the Universe, and more than 90 percent of all the atoms, we’re all pretty well acquainted with hydrogen.

But the simplest and most abundant element in the Universe still has some tricks up its sleeve, because physicists have just created a never-before-seen form of hydrogen - negatively charged hydrogen clusters.

To understand what negatively charged hydrogen clusters are, you first have to wrap your head around their far more common counterparts - positively charged hydrogen clusters.

Positively charged hydrogen clusters are pretty much exactly what they sound like - positively charged clusters of a few or many hydrogen molecules.

Known simply as hydrogen ion clusters, they form at very low temperatures, and can contain as many as 100 individual atoms.

Physicists confirmed the existence of hydrogen ion clusters some 40 years ago, and while a negative counterpart to these clusters boasting large numbers of atoms were theorised, no one could figure out how to create one.

But that didn’t stop a team of physicists led by Michael Renzler from the University of Innsbruck in Austria from giving it a shot.

Continue Reading.

- Carl Sagan, Cosmos.

(Giphy)

An excerpt from Time Magazines 10 Questions: Neil deGrasse Tyson.

(Time)