Learning Not to Fear, Faster
- Department of Physiology, Ponce School of Medicine, Ponce, Puerto Rico 00732
This extract was created in the absence of an abstract.
Overcoming our fears is on everyone's “to do” list. However, this is more difficult for some than others, especially those suffering from posttraumatic stress disorder (PTSD). To understand how the brain learns to feel safe, researchers have turned to extinction of classically conditioned fear. In extinction, mice learn that a tone previously paired with a footshock no longer predicts the shock and is therefore no longer dangerous. One promise of extinction research is the possibility of accelerating extinction learning, with the hope of facilitating extinction-based exposure therapy used to treat PTSD sufferers.
In this issue of Learning and Memory, Cain et al. (2004) make good on that promise by showing that the noradrenergic antagonist yohimbine accelerates extinction learning in mice. Yohimbine increases release of norepinephrine from nerve terminals by blocking α2 autoreceptors. Mice given systemic yohimbine extinguished their conditioned freezing responses in far fewer trials than controls. Mice …
