research finding may accelerate the development of treatments for PTSD -
TAC2 major gene for fear memory consolidation
Scientists at the Yerkes National primate Research Center, Emory University have identified a drug that seems to make memories of terrible events lasting less mice.
conclusion may accelerate the development of treatments to prevent PTSD (post-traumatic stress disorder). The drug, called osanetant targets a distinct group of brain cells in a brain region that controls the formation and consolidation of memories of fear.
The results were published in the journal Neuron .
"potentially, drugs that affect this group of cells could be used to block memory consolidation of fear shortly after exposure to trauma, which would help prevent PTSD," says Kerry Ressler, MD, PhD, professor of psychiatry and behavioral sciences at Emory University school of Medicine and Yerkes National Primate Research Center "PTSD is unique among psychiatric disorders in what we know when it begins. - when trauma of finding ways to prevent its development in the first place. - in emergency or battlefield Service - is an important and exciting avenue of research in this field "
the first author. Article is postdoctoral fellow Ra-l Ander Gal, PhD.
Ressler and Ander were sifting through a list of many genes that are activated in mouse brains after they learn to be afraid of her, because the sound is associated with a slight shock electric. The researchers were probing changes in the central amygdala, a region of the brain known to regulate learning of fear.
Of the thousands of genes they examined, their "top gene" was tachykinin 2 or TAC2. TAC2 The gene was turned on more strongly during fear learning in mice that were previously exposed a model of post-traumatic stress ..
"the gene is robust TAC2 activated after learning of fear and belongs to a path that can be specifically blocked with a drug," says Ressler. "He Interestingly TAC2 that is highly expressed in a particular part of the amygdala, but with little or no expression in other brain areas related to the formation of fear memories. In addition, we found that cells that express TAC2 are distinct from those of other investigators had previously identified as being involved in the expression of fear. "
TAC2 is part of a family of messengers in the nervous system known as tachykinins. Drugs that block a product encoded by report of TAC1 TAC2 are antiemetics, often prescribed when someone receives chemotherapy for cancer.
Osanetant, which blocks the action of TAC2, was tested in previous clinical trials for schizophrenia and was safe but not effective in the fight against this disease. He has not been tested in humans for the prevention of post-traumatic stress.
"Osanetant is a safe drug and well tolerated in humans and could be potentially used to prevent PTSD when given little after trauma, although more research is needed, "Ander said.
Under the influence of osanetant, mice could still learn to be afraid of a sound associated with a shock, but the mice did not freeze in response to sound as one day later, even if the drug was administered one hour after training.
"Our goal is to specifically impair emotional memories of a traumatic event instead of all the memories associated with it. Thus, the trauma and the circumstances are recalled, but the consolidation of fear memories is impaired, which could decrease the likelihood of developing fear-related disorders, "said Ander.
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