*A 'stellate ganglion block' is an injection of anesthetic into a nerve cluster called the stellate ganglion, which connects the brain to the body

*This nerve cluster is key for controlling our response to perceived danger

*Scientists claim one shot to numb this cluster can 'reset' our nervous system

*The injection has been used successfully since it was invented in Illinois in 2006

*Now the US Army has invested $2m in US studies to confirm its effectiveness before endorsing it as a standard treatment method

The US Army has invested $2 million in research to test a promising one-shot injection to treat post-traumatic stress disorder. 

The injection - known as stellate ganglion blocks - was invented in 2006, and is used to 'reset' the nervous system in soldiers tormented by past trauma.

Now the Pentagon is backing a major study carried out at three Army medical centers to investigate the treatment.

The method is simple: a physician injects a dose of local anesthetic into the right hand side of the neck, hitting and numbing a cluster of nerves called the stellate ganglion, which connect the body to the brain.

Somehow - for reasons that remain unclear to scientists - this injection seems to reset the nervous system.