Glass houses for Hermit crabs.


Staff at the aquarium were intrigued how hermit crabs make their homes in discarded snail shells, it was often asked “How do they manage to squeeze their entire body into such a small space?” or “Wouldn’t it be cool to see inside?”

Enlisting the expertise of University of Otago scientific glass blower Anne Ryan, the aquarium wanted to replicate a snail shell that would be suitable home for a hermit crab. With the hermit crab taking up residence, it is now clearly visible how they twist their abdomen around the central column of the shell and the well-adapted tip of the abdomen clasps strongly to hold it in place.

Centre Manager, Tessa Mills said “The staff are so excited. This is going to provide us with new teaching opportunities and will be really fantastic for the public to come and view.” More glass shells have been requested, so soon there may be a whole cast of hermit crabs living in glass shells at Portobello.

Source: http://www.sciences.otago.ac.nz

 

 

 

Growing New Neurons.


Brain cells called pericytes can be reprogrammed into neurons with just two proteins, pointing to a novel way to treat neurodegenerative disorders.

Making new neurons in the brain may not be as hard as once believed. Using just two proteins and without any cell divisions, scientists from Ludwig-Maximilians University Munich succeeded in reprogramming brain cells known as pericytes into neurons in both cultured cells from humans and mice. The findings, published today (October 4) in Cell Stem Cell, could have implications for patients with degenerative brain disorders.

“We are not there yet, but the hope is that we can eventually treat neurodegenerative diseases like Parkinson’s by in situ reprogramming,” said Ludwig-Maximilians’ Benedikt Berninger, lead author on the study.

Since 2011, other scientists including Marius Wernig, a stem cell biologist from the Stanford School of Medicine, have transformed skin cells directly into neurons using three or four proteins. But the conversion was performed in vitro, and such cells would still have to be implanted into the brain via invasive surgeries to replace the dying neurons of Parkinson’s or Alzheimer’s patients. Berninger’s team has now accomplished the same feat using other cells found in the brain, making it theoretically possible to induce the transformation in vivo.

“It is an exciting paper,” said Wernig. “This kind of treatment would be much easier because no cell transplantation would be involved.” A similar approach was recently shown to work in the hearts of living mice, as researchers were able to transform scar tissue into beating muscle cells, proving that such an in vivo conversion approach may be feasible.

To see if the brain would also lend itself to such manipulation, postdoc Marisa Karow and graduate student Rodrigo Sanchez collected 30 samples of brain tissue from areas that had been removed from patients undergoing surgery for epilepsy. They created cell cultures from these samples, and found that they were rich in pericytes. “Pericytes are very exciting cells, the biology of which is only now being uncovered,” said Berninger. They help to control the flow of blood in the brain, and they build and maintain the blood-brain barrier.

Karow and Sanchez converted human pericytes into neurons using viruses to smuggle in two transcription factors—Mash1, which has also been used to transform skin cells into neurons, and Sox2, which has been used in mice to transform other brain cells called astroglia into neurons. Within 4 to 5 weeks, many of the pericytes successfully reprogrammed into neurons: around half of them contained beta-III-tubulin, a protein found only in neurons, and more than 25 percent had taken on a uniquely neuronal shape. The researchers even filmed these transformations using time-lapse video microscopes.

The same technique worked in mouse cells, and even more efficiently. The newborn neurons took on the right shape, fired off electrical impulses, integrated into existing networks in culture, and seemed to produce the neurotransmitter GABA.

Berninger said that he still does not understand precisely how the reprogramming works. “We believe that Mash1 and Sox2 superimpose a neuronal program onto a cell that has another program running,” he said, “but we are keen to understand the exact mechanisms.”

He also wants to make the technique more efficient. In the cultured human cells, more than 36 percent of the reprogrammed cells died, compared to just 3 percent of untouched ones. Furthermore, changing fates can be catastrophic for the pericytes, and some of the cells that did reprogram didn’t survive. In the end, just 19 percent of the pericytes converted to healthy neurons—too low an efficiency for clinical use.

By finding out how the reprogramming works, Berninger hopes to better understand why it fails in so many cells. “Ultimately, we would like to replace the transcription factors by small molecules that would do the same job,” he said.

Source: http://www.the-scientist.com

 

 

Language Learning Makes the Brain Grow, Swedish Study Suggests.


At the Swedish Armed Forces Interpreter Academy, young recruits learn a new language at a very fast pace. By measuring their brains before and after the language training, a group of researchers has had an almost unique opportunity to observe what happens to the brain when we learn a new language in a short period of time.

At the Swedish Armed Forces Interpreter Academy in the city of Uppsala, young people with a flair for languages go from having no knowledge of a language such as Arabic, Russian or Dari to speaking it fluently in the space of 13 months. From morning to evening, weekdays and weekends, the recruits study at a pace unlike on any other language course.

As a control group, the researchers used medicine and cognitive science students at Umeå University — students who also study hard, but not languages. Both groups were given MRI scans before and after a three-month period of intensive study. While the brain structure of the control group remained unchanged, specific parts of the brain of the language students grew. The parts that developed in size were the hippocampus, a deep-lying brain structure that is involved in learning new material and spatial navigation, and three areas in the cerebral cortex.

“We were surprised that different parts of the brain developed to different degrees depending on how well the students performed and how much effort they had had to put in to keep up with the course,” says Johan Mårtensson, a researcher in psychology at Lund University, Sweden.

Students with greater growth in the hippocampus and areas of the cerebral cortex related to language learning (superior temporal gyrus) had better language skills than the other students. In students who had to put more effort into their learning, greater growth was seen in an area of the motor region of the cerebral cortex (middle frontal gyrus). The areas of the brain in which the changes take place are thus linked to how easy one finds it to learn a language and development varies according to performance.

Previous research from other groups has indicated that Alzheimer’s disease has a later onset in bilingual or multilingual groups.

“Even if we cannot compare three months of intensive language study with a lifetime of being bilingual, there is a lot to suggest that learning languages is a good way to keep the brain in shape,” says Johan Mårtensson.

Source: Science Daily