Release from helplessness and stress

A possible therapy from over-expressing a gene? From 'research highlights' in a recent issue of Nature, edited:

When mice experience recurrent, inescapable stress, some simply stop trying to get away. This behaviour, called 'learned helplessness', is relieved by antidepressants and is used to model depression and post-traumatic stress disorder.

It now appears that a protein called ΔFosB (a transcription factor that down regulates the substance P gene) may help mice to cope with repeated stress.

Eric Nestler of the University of Texas Southwestern Medical Center in Dallas and his colleagues (Berton et al. in Neuron) have found that ΔFosB is expressed by neurons that contain a pain-signalling peptide called substance P, in a brain region called the periaqueductal gray. Over-expressing ΔFosB in stressed mice diminishes stress-induced release of substance P, and reduces learned helplessness.