To further examine the relationship between HTR7, TRPA1 and itch, the scientists examined how molecules that bind to the HTR7 receptor affect neurons and mice lacking one or both of those proteins. “Seeing HTR7 as one of those genes that were most correlated with itch behavior got us really excited,” said Dr. In fact, the HTR7 gene was twice as active in the itchiest mice compared to the least sensitive mice. Of these, the gene for the HTR7 receptor was the most closely linked to itch. The researchers found more than 70 genes whose expression was higher in the more itch-sensitive mice.
“We looked for genes whose expression went up and down in a manner that paralleled itch itself.” “Not all mice scratched to the same extent even though they were treated exactly the same,” said Rachel Brem, Ph.D., the study’s other senior author and an associate professor at the Buck Institute. The team thought this might be due to differences in gene expression – the extent to which a gene is active – in sensory neurons in the mice’s skin. The researchers began their study by injecting genetically distinct mice with itch-inducing compounds and noted that this produced widely varying periods of scratching among the animals. Both receptors seem to be working together to mediate chronic itch.” “We tried a variety of experiments and found that HTR7 communicates with the TRPA1 ion channel. “For neurons to become excited, you need a receptor to communicate with an ion channel,” said Dr. This increases the neurons’ firing rates and triggers the sensation of itch.
#CANT FIND NIH IN HUMAN BRAIN MAPPING SKIN#
The team learned that when serotonin binds to a receptor called HTR7 in skin sensory neurons, it leads to the opening of an ion channel called TRPA1. These interactions cause the neuron’s ion channels to open, which in turn influences the flow of ions into and out of the neuron and alters its activity. Many neurons have proteins on their surfaces called receptors that serve as binding sites for specific chemicals. Bautista’s team is the first to discover why. Scientists have long known that high levels of serotonin in the skin cause persistent itching, but Dr. “Unlike the itch associated with a mosquito bite, chronic itch is incredibly debilitating and there are very few therapies available, so it’s a really important unmet clinical problem.” “It’s thought that 1 in 10 people will suffer from chronic itch at some point in their lifetime,” said co-senior author Diana Bautista, Ph.D., an associate professor in the Department of Molecular and Cell Biology at UC Berkeley. The study, published in Neuron and partially funded by the NIH’s National Institute of Neurological Disorders and Stroke ( NINDS), may lead to treatments that can stop an itch at its source. Scientists from the Buck Institute for Research on Aging and the University of California, Berkeley have identified a pair of proteins responsible for chronic itching. NIH-funded study identifies proteins that may cause chronic itchĮveryone knows the best way to suppress an itch is to scratch it, but for people who suffer from skin diseases like eczema, no amount of scratching can bring relief.
0 kommentar(er)
