Tag Archives: neurons

How To Reverse Congenital Blindness

Researchers funded by the  American National Eye Institute (NEI) have reversed congenital blindness in mice by changing supportive cells in the retina called Müller glia into rod photoreceptors. The findings advance efforts toward regenerative therapies for blinding diseases such as age-related macular degeneration and retinitis pigmentosa. A report of the findings appears online today in Nature. NEI is part of the National Institutes of Health.

This is the first report of scientists reprogramming Müller glia to become functional in the mammalian ,” said Thomas N. Greenwell, Ph.D., NEI program director for retinal neuroscience. “Rods allow us to see in low light, but they may also help preserve cone photoreceptors, which are important for color vision and high visual acuity. Cones tend to die in later-stage eye diseases. If rods can be regenerated from inside the eye, this might be a strategy for treating diseases of the eye that affect photoreceptors.”

Photoreceptors are light-sensitive cells in the retina in the back of the eye that signal the brain when activated. In mammals, including and humans, photoreceptors fail to regenerate on their own. Like most neurons, once mature they don’t divide.

Scientists have long studied the regenerative potential of Müller glia because in other species, such as zebrafish, they divide in response to injury and can turn into photoreceptors and other retinal neurons. The zebrafish can thus regain vision after severe retinal injury. In the lab, however, scientists can coax mammalian Müller glia to behave more like they do in the fish. But it requires injuring the tissue.

From a practical standpoint, if you’re trying to regenerate the retina to restore a person’s vision, it is counterproductive to injure it first to activate the Müller glia,” said Bo Chen, Ph.D., associate professor of ophthalmology and director of the Ocular Stem Cell Program at the Icahn School of Medicine at Mount Sinai, New York.

We wanted to see if we could program Müller glia to become rod photoreceptors in a living mouse without having to injure its retina,” added Chen, the study’s lead investigator.

Source: https://www.nih.gov/
AND
https://medicalxpress.com/

Growing New Cartilage To Eradicate Osteoarthritis Pain

What is graphene foam? It’s a synthetic “wonder material” made from the same carbon atoms that make up the lead in a pencilGraphene foam can be used as a “bioscaffold” to mesh with human stem cells and grow new cartilage. In addition to being incredibly strong, graphene foam conducts heat and electricity which helps neurons, or nerve cells, transmit information. Boise State researchers believe graphene foam-enhanced cartilage could one day be used to treat the joint pain caused by osteoarthritis as well as prevent the need for joint replacement. Osteoarthritis is incurable and affects half the U.S. population over the age of 65.

If we could take graphene foam, adhere a patient’s own stem cells on it then and inject that into someone’s knee to regrow their own cartilage, that would be the ‘pie in the sky,‘” said Dave Estrada, co-director of the Boise State University’s Advanced Nanomaterials and Manufacturing Laboratory.

A Boise State team led by Katie Yocham, a doctoral student in the Micron School of Materials Science and Engineering, and Estrada have published a study, “Mechanical Properties of Graphene Foam and Graphene Foam-Tissue Composites,” in the Advanced Engineering Materials journal.

While earlier studies at Boise State have shown that graphene foam is compatible with cells for growing new cartilage tissue, this is the first study to investigate how that tissue would actually function in a human joint under normal stresses, including high impact activities.

Trevor Lujan, an associate professor in the Department of Mechanical and Biomedical Engineering, and one of the authors of the study, praised Yocham’s work. “Katie’s strong efforts on this project have provided the biomedical community with a rigorous characterization of the bulk mechanical behavior of cellularized graphene foam. This baseline knowledge is an important step in the rising use of graphene foam for biomedical applications,” he said.

Estrada believes the biomedical use of graphene foam may have other applications, including in the military where a majority combat injuries involve the musculoskeletal system. “Our vision is to develop novel bioscaffolds that can expedite healing, reduce the need for amputation, and help save lives,” he added.

Source: https://news.boisestate.edu/

Graphene Strengthens Neuronal Activity

A work led by SISSA in Italy and published on Nature Nanotechnology reports for the first time experimentally the phenomenon of iontrapping’ by graphene carpets and its effect on the communication between neurons.The researchers have observed an increase in the activity of nerve cells grown on a single layer of graphene. Combining theoretical and experimental approaches they have shown that the phenomenon is due to the ability of the material to ‘trap’ several ions present in the surrounding environment on its surface, modulating its composition.

Graphene is the thinnest bi-dimensional material available today, characterisedby incredible properties of conductivity, flexibility and transparency. Although there are great expectations for its applications in the biomedical field, only very few works have analysed its interactions with neuronal tissue.
A study conducted by SISSAScuola Internazionale Superiore di Studi
Avanzati, and the University of Trieste in association with the University of Antwerp (Belgium), the Institute of Science and Technology of Barcelona (Spain), has analysed the behaviour of neurons grown on a single layer of graphene, observing a strengthening in their activity. Through theoretical and experimental approaches the researchers have shown that such behaviour is due to reduced ion mobility, in particular of potassium, to the neuron-graphene interface. This phenomenon is commonly called ‘ion trapping’, already known at theoretical level, but observed experimentally for the first time only now.

“It is as if graphene behaves as an ultra-thin magnet on whose surface some of the potassium ions present in the extra cellular solution between the cells and the graphene remain trapped.
It is this small variation that determines the increase in neuronal
excitability” comments Denis Scaini, researcher at SISSA who has led the research alongside Laura Ballerini.
The study has also shown that this strengthening occurs when the graphene itself is supported by an insulator, like glass, or suspended in solution, while it disappears when lying on a conductor. “Graphene is a highly conductive material which could potentially be used to coat any surface. Understanding how its behaviour varies according to the substratum on which it is laid is essential for its future applications, above all in the neurological field” continues Scaini, “considering the unique properties of graphene it is natural to think for example about the development of innovative electrodes of cerebral stimulation or visual devices“.

Source: https://www.sissa.it/

Genes Behind Humankind’s Big Brain

Scientists have pinpointed three genes that may have played a pivotal role in an important milestone in human evolution: the striking increase in brain size that facilitated cognitive advances that helped define what it means to be human. These genes, found only in people, appeared between 3 and 4 million years ago, just prior to a period when the fossil record demonstrates a dramatic brain enlargement in ancestral species in the human lineage, researchers said. The three nearly identical genes, as well as a fourth nonfunctional one, are called NOTCH2NL genes, arising from a gene family dating back hundreds of millions of years and heavily involved in embryonic development. 

The NOTCH2NL genes are particularly active in the reservoir of neural stem cells of the cerebral cortex, the brain’s outer layer responsible for the highest mental functions such as cognition, language, memory, reasoning and consciousness. The genes were found to delay development of cortical stem cells into neurons in the embryo, leading to the production of a higher number of mature nerve cells in this brain region.

The cerebral cortex defines to a large extent what we are as a species and who we are as individuals. Understanding how it emerged in evolution is a fascinating question, touching at the basic origins of mankind,” said developmental neurobiologist Pierre Vanderhaeghen of Université Libre de Bruxelles and VIB/KULeuven in Belgium.

It is the ultimate evolutionary question and it is thrilling to work in this area of research,” added biomolecular engineer David Haussler, scientific director of the University of California, Santa Cruz Genomics Institute and a Howard Hughes Medical Institute investigator.

Source: https://www.reuters.com/

 

How To Deliver Drug Deep In The Brain

By learning how rabies virus travels in the brain, Anti-Parkinson’s drug can be delivered deep in the brain where currently the drugs are not able to reachRabies virus has the capability to trick the nervous system and cross the blood brain barrier. This trick could be used for drug design. Glycoprotein 29 present on the rabies virus is attached to a nanoparticle stuffed full of deferoxamine ( Anti-Parkinson’s medication) and injected into the brain to trick the brain.

Rabies virus may have some tricks to bypass the blood brain barrier, this trick can be used to treat disease that require drugs to effectively cross the blood brain barrier, finds a new study.

The researchers can now exploit rabies viruses machinery to deliver a Parkinson’s disease medication directly to the brain. Upon injection the nanoparticles grab excess iron and relieve symptoms. While the common cause of Parkinson’s disease is unknown, it has been proved that accumulation of iron in neurons is one of the commonest features of Parkinson’s disease.

Deferoxamine is a metal-grabbing compound and sop up the excess iron in patients. But a large quantity of this drug needs to reach the brain in order for them work.
To usher deferoxamine into the brain, the researchers Yan-Zhong Chang, Xin Lou, Guangjun Nie took advantage of a key part of the rabies virusGlycoprotein 29.
When they injected this iron-grabbing nanoparticles into mouse models of Parkinson’s disease, the iron levels dropped and this reduced brain damage caused by Parkinson’s disease.

The findings of this study is published in the ACS Nano journal.

Source: https://www.acs.org/