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Axon
An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma. Axons are in effect the primary transmission lines of the nervous system, and as bundles they help make up nerves. Individual axons are microscopic in diameter - typically about one micrometre across - but may extend to macroscopic lengths. The longest axons in the human body, for example, are those of the sciatic nerve, which run from the base of the spine to the big toe of each foot. These single-cell fibers may extend a meter or even longer.
In vertebrates, the axons of many neurons are sheathed in myelin, which is formed by either of two types of glial cells: Schwann cells ensheathing peripheral neurons and oligodendrocytes insulating those of the central nervous system.
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Health & Medicine News
August 29, 2026
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Aug. 28, 2026 Scientists have identified a protein that acts like a brake on the nervous system’s ability to repair damaged connections. Blocking AHR helped injured nerve fibers regrow and improved movement and sensation in mice with nerve or spinal cord ...
Aug. 28, 2026 Scientists have created light-activated drugs that helped blind mice perceive light again and restored visually guided behavior without gene therapy, implants, or specialized lighting. Even more intriguingly, two of the most promising compounds ...
Aug. 28, 2026 A popular vanilla flavoring in e-cigarettes may interfere with some of the earliest steps of human development. In lab experiments, vanillin caused embryonic stem cells to lose their ability to develop normally and pushed them toward forming only ...
Aug. 28, 2026 Every one of 212 plant-based meat alternatives and drinks tested in the UK contained at least one naturally occurring fungal toxin, though concentrations remained below recommended EU guideline ...
Aug. 27, 2026 Ultra-processed foods make up a huge share of the American diet, and new research suggests they may carry another serious health risk for men. In a nationally representative study of more than 17,000 U.S. men, those who ate more ultra-processed ...
Aug. 27, 2026 The belief that huge doses of vitamin C can ward off colds was popularized more than 50 years ago by Nobel Prize winner Linus Pauling. Since then, larger studies have found that vitamin C does not prevent most people from catching a cold, although ...
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Aug. 27, 2026 Researchers discovered a brain-based “brake” that can shut down chronic nerve pain in mice by calming an overactive pain circuit. Targeting this system more precisely could one day lead to powerful pain relief without affecting opioid receptors ...
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Aug. 26, 2026 Moderate calorie restriction lowered an immune protein called C3 that appears to help drive chronic inflammation as the body ages. Blocking the same ...
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Aug. 26, 2026 Early-life stress may physically alter how DNA is packaged in the brain, leaving stress-related genes primed to activate more easily years later. In mice, researchers were able to block this effect, ...
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