London, Jan 30 (UNI) Scientists have pinned down a protein that provides humans the ability to identify frightening situations and act in a timid, tentative and cautious manner.
The protein tPA (tissue plasminogen activator) found in hippocampus, a part of the brain that controls memory, learning and fear if deficient can lead to depression and a decreased ability to recognise dangerous situations.
Rockefeller scientists, Sidney Strickland and Erin Norris, found that the protein played a role in neural plasticity in the brain affecting memory, learning ability and anxiety.
They compared behaviour of normal mice to tPA-deficient ones to determine their ability to learn from stressful experiences. The study revealed that the normal rodents learnt from past experiences, while the tPA deficient ones were either less fearful of their situation or could not remember their training.
It was compiled that lacking tPA resulted in non-performance of receptor that resided at the cell membrane and changed its location during stress in normal mice. Without the receptor's change in position, there could be no stress response.
Experts believe that tPA could be an important factor in depression, since stress has been shown to lead to this disorder in humans.
UNI XC SYU VC1152