Researchers have developed a model to simulate blood flow in brain aneurysms using a combination of technologies.
Category: neuroscience – Page 81
Switching on a silent gene revives tissue regeneration in mice
Research led by the National Institute of Biological Sciences in Beijing has discovered that switching on a single dormant gene enables mice to regenerate ear tissue.
Some vertebrates such as salamanders and fish can regenerate complex tissue structures with precision. A lost limb can be regrown, a damaged heart or eye can be repaired. Salamanders are so remarkable at reconstructing damaged tissues that even a spinal cord injury with severed neural motor connectivity can be restored.
Mammals occasionally showcase the ability to regenerate. Deer antlers and goat horns are examples of living tissue regeneration. Mice can regrow fingertips if they are lost. A healthy human liver can experience up to 70% loss of tissue and regrow to near full size within several weeks.
Inverse Graphics: How Your Brain Turns 2D Into 3D
“This gives us evidence that the goal of vision is to establish a 3D understanding of an object,” said study senior author Ilker Yildirim, an assistant professor of psychology in Yale’s Faculty of Arts and Sciences.
“When you open your eyes, you see 3D scenes — the brain’s visual system is able to construct a 3D understanding from a stripped-down 2D view.”
Researchers have dubbed this process “inverse graphics,” describing how the brain’s visual processing system works like a computer graphics process, but in reverse, from a 2D image through a less view-dependent “2.5D” intermediate representation, and up to a much more view-tolerant 3D object.
Over 400 different types of nerve cell have been grown — far more than ever before
Nerve cells are not just nerve cells. Depending on how finely we distinguish, there are several hundred to several thousand different types of nerve cell in the human brain according to the latest calculations. These cell types vary in their function, in the number and length of their cellular appendages, and in their interconnections. They emit different neurotransmitters into our synapses and, depending on the region of the brain – for example, the cerebral cortex or the midbrain – different cell types are active.
When scientists produced nerve cells from stem cells in Petri dishes for their experiments in the past, it was not possible to take their vast diversity into account. Until now, researchers had only developed procedures for growing a few dozen different types of nerve cell in vitro. They achieved this using genetic engineering or by adding signalling molecules to activate particular cellular signalling pathways. However, they never got close to achieving the diversity of hundreds or thousands of different nerve cell types that actually exists.
“Neurons derived from stem cells are frequently used to study diseases. But up to now, researchers have often ignored which precise types of neuron they are working with,” says Barbara Treutlein, Professor at the Department of Biosystems Science and Engineering at ETH Zurich in Basel. However, this is not the best approach to such work. “If we want to develop cell culture models for diseases and disorders such as Alzheimer’s, Parkinson’s and depression, we need to take the specific type of nerve cell involved into consideration.”
For the first time, researchers at ETH Zurich have successfully produced hundreds of different types of nerve cell from human stem cells in Petri dishes. In the future, it will thus be possible to investigate neurological disorders using cell cultures instead of animal testing.
First Stem Cell Nerve Therapy Meant to Reverse Paralysis Enters Clinical Trial
It begins with a fall, a crash, or a sudden jolt. In a split second, the spinal cord shatters. For millions, the damage is permanent. But in Shanghai and Suzhou, a group of scientists believes that might soon change.
This May, a biotech startup named XellSmart Biopharmaceutical received rare dual approval from both U.S. and Chinese regulators to launch a Phase I trial for an experimental treatment. The therapy is designed to repair spinal cord injuries using neurons grown in a lab.
The trial, described as the first of its kind, is being led by the Third Affiliated Hospital of Sun Yat-sen University in China. The goal: to test whether specialized nerve cells can be safely implanted into people whose spinal cords were recently injured.
A cell therapy for regenerating broken spinal cord using lab-grown neurons enters human trials for the first time.
