myelin

Multiple sclerosis (MS) is an autoimmune disease in which the immune system mistakenly attacks the protective coating that surrounds nerve fibers and helps them function. Damage to this protective coating, called myelin, means the nerve fibers are fragile and easily damaged. MS in children, or pediatric MS, is…

Blocking a protein called PAR1 may enhance the regeneration of myelin, the protective fatty layer that covers nerve fibers and is damaged in multiple sclerosis (MS), a mouse study shows. Therapeutic targeting of PAR1 may promote remyelination and delay MS progression, according to the study, “Blocking the Thrombin Receptor…

MetP Pharma‘s patent application for a new method to treat demyelinating and neuroinflammatory diseases, including multiple sclerosis (MS), has been approved by the United States Patent and Trademark Office (USPTO). The patent, titled “Treatment of Demyelinating Diseases” (U.S. Appl. No. 16/506,830), is valid until 2039,…

Two potassium ion channels located at gaps between segments of myelin are required for high frequency and high-speed conduction of electrical impulses along myelin-rich nerves, a study shows. Loss of the workings of these potassium channels in what are called the nodes of Ranvier slowed nerve conduction, and impaired the sensory response of a rat. These findings suggest that similar problems with these channels may exist in people with multiple sclerosis (MS). The study “TREK-1 and TRAAK Are Principal K+ Channels at the Nodes of Ranvier for Rapid Action Potential Conduction on Mammalian Myelinated Afferent Nerves” was published in the journal Neuron. Myelin, the fat-rich substance that wraps around nerve fibers (axons), works to insulate and increase the velocity of the signals relayed by nerve cells. Gaps between segments of myelin, or nodes of Ranvier, also work to amplify these signals. Nerve impulses must travel and arrive at relay points extremely quickly for effective connection and communication between brain regions. Researchers at the University of Alabama at Birmingham (UAB) showed for the first time that the nodes of Ranvier have potassium channels that allow the myelinated nerves to propagate nerve impulses at very high frequencies, and with high conduction speeds. This is key for fast transmission of sensations and rapid muscle control in mammals. The nodes of Ranvier were first discovered in 1878 by the French scientist Louis-Antoine Ranvier. Later research, dating from 1939, showed that they work as relay stations placed along myelinated nerves — about 1 millimeter apart — for proper conduction of nerve impulses at rates of 50 to 200 meters per second. Between these nodes, the nerve is wrapped in myelin. When the nerve fires, the electrical impulse travels along the nerve (called action potential) from one node to the other at a speed 100 times faster than that of impulses in nerves lacking myelin. Neuroscientists know that ions crossing the membrane of nerve cells are required to fire electrical impulses along nerves, but whether potassium ion channels were present in the nodes of Ranvier remained a matter of debate. No one had been able to use patch clamps — a technique that allows recording of whole-cell or single-ion channel currents flowing across membranes — to the nodes of the small intact nerves in mammals. UAB researchers led by Jianguo Gu, PhD, worked with a rat and identified two ion channels, called TREK-1 and TRAAK, as the main potassium channels in the nodes of Ranvier of the rat’s myelinated nerve. Most importantly, they showed these ion channels allow high-speed and high frequency conduction of nerve impulses along the myelinated afferent nerves — those carrying information from the sensory organs (like the eyes or skin) to the central nervous system (the brain and spinal cord). TREK-1 and TRAAK channels were highly enriched — 3,000 times higher — at the nodes of Ranvier in afferent nerves than in the nerve cell’s body. When the scientists removed (knocked down) these channels, conduction speed in the rat's nerve dropped by 50 percent, and the rat's "aversion reaction" to its whisker being flicked was slower. "TREK-1 and TRAAK are clustered at nodes of Ranvier of myelinated afferent nerves," the researchers concluded, and "suppressing these channels retards nerve conduction and impairs sensory functions." Increasing evidence shows that dysfunction in the nodes of Ranvier are present in neurological diseases, including MS. Whether autoantibodies (antibodies that attack the body’s own tissues) target the TREK-1 and TRAAK to affect nerve conduction, leading to sensory and motor problems such as those seen in MS, remains to be investigated, Gu said in a UAB news release written by Jeff Hansen.

Blocking production of the low-density lipoprotein receptor-related protein 1 (LRP1) — involved in inflammatory and immune responses — specifically in myelin repair cells halts neuroinflammation and promotes myelin repair, a preclinical study shows. These results, from two mouse models of multiple sclerosis (MS), shed light on the underlying mechanisms…

A diagnosis of multiple sclerosis (MS) often leaves patients and their families with many unanswered questions. It can be hard to find information, connect with other patients, and find support. Here are some frequently asked questions and answers about MS: What is MS? MS is an autoimmune disease —…

Two new studies delve into the structure of SARM1, an enzyme that plays a key role in nerve cell degeneration, and are expected to aid the development of targeted therapies for neurodegenerative disorders such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and peripheral neuropathies. SARM1…

A new study demonstrates that intracellular sigma peptide (ISP) can promote remyelination in a mouse model of multiple sclerosis (MS). Importantly, this study was independent of NervGen, a pharmaceutical company that is developing an ISP-like compound — NVG-291 — for the treatment of nerve injury and MS. The study,…

NervGen wants to advance the development of NVG-291, its lead investigational therapy for spinal cord damage, as a potential remyelination treatment for multiple sclerosis (MS), the company announced. Following preclinical data showing that NVG-291 promotes myelin repair and regeneration of damaged nerves in animal models of…

Editor’s note: “Need to Know” is a series inspired by common forum questions and comments from readers. Have a comment or question about MS? Visit our forum. This week’s question is inspired by the forum topic “How the Blood Brain Barrier May Thwart MS Progression” from Feb. 9, 2017. What…

Exosomes — tiny vesicles secreted by cells — collected from bone marrow stem cells and injected into a mouse model of multiple sclerosis (MS) helped to treat the disease, a study reports. Specifically, this treatment eased myelin loss and neuroinflammation in the mice, and improved motor function, the…

Giving estrogen to two different adult mouse models of multiple sclerosis (MS), including the experimental autoimmune encephalomyelitis (EAE) model, promoted remyelination, a new study shows. Exposure to the hormone affected gene activity in oligodendrocytes, tricking them into producing myelin (the fatty substance that protects nerve cells, and that is destroyed…