Calcium, the most abundant mineral in the body, is found in some foods, added to others, available as a dietary supplement, and present in some medicines (such as antacids). Calcium is required for muscle contraction, blood vessel expansion and contraction, secretion of hormones and enzymes, and transmitting impulses throughout the nervous system. The body strives to maintain constant concentrations of calcium in blood, muscle, and intercellular fluids, though less than <1% of total body calcium is needed to support these functions.
The remaining 99% of the body's calcium supply is stored in the bones and teeth where it supports their structure. Bone itself undergoes continuous remodeling, with constant resorption and deposition of calcium into new bone. The balance between bone resorption and deposition changes with age. Bone formation exceeds resorption in growing children, whereas in early and middle adulthood both processes are relatively equal. In aging adults, particularly among postmenopausal women, bone breakdown exceeds formation, resulting in bone loss that increases the risk of osteoporosis over time.
Like people, neurons need to talk to one another. But instead of turning thoughts into words, these cells convert electrical signals into chemical ones. For nearly 30 years, biochemist Edwin Chapman has studied how one protein triggers this crucial conversion.
Researchers in Pennsylvania and Texas have discovered a novel protein sensor that limits the amounts of fat and sugar that are converted into energy by human cells, during the starvation periods.
Experts at the University of Tokyo have identified a new protein in the pathway that leads to Alzheimer's disease. Researchers used the "molecular scissors" of CRISPR/Cas9 to search for new genes related to the neurodegenerative disease.
Biophysicists from the Moscow Institute of Physics and Technology and the University of Groningen in the Netherlands have visualized a nearly complete transport cycle of the mammalian glutamate transporter homolog from archaea.
The glutamate receptors do not actually adhere to “distance keeping.” Now, high-resolution microscopic studies have revealed that the receptors often appear in small groups at the synapses and remain in contact with other proteins.
A research team, which also included scientists from the National Synchrotron Light Source II (NSLS-II), has reported a novel method for imaging proteins in three dimensions (3D) with nanoscale resolution.
Our brain contains tens of billions of nerve cells (neurons) which constantly communicate with each other by sending chemical and electrical flashes, each lasting a short one millisecond (0.001 sec). In every millisecond, these billions of swift-flying flashes altogether traveling in a giant star-map in the brain that lights up a tortuous glittering pattern.
Ion channels that permit potassium and sodium ions to move in and out of cells are essential for the function of the brain and heart, and also for neuronal “firing” in the central nervous system.