In 2013, Columbia University neuroscientists Rebecca Brachman and Christine Ann Denny were investigating the effects on mice of the anaesthetic ketamine, which has recently attracted attention for inducing rapid but short-lived remissions of depression in humans and is also used as an illegal recreational psychedelic, “Special K.”
They were using mice who had been stressed to see if ketamine could counter their resultant depression-like behaviors. Because their lab was cash-strapped, they planned to wait a week and reuse the same mice on another round of ketamine trials, but it didn’t work. Mice who had been administered ketamine the week before could no longer be made to exhibit any stress. It appeared that the ketamine had inoculated them against the effects of stressful experience. The investigators, rightfully skeptical of this conclusion, were able to replicate the findings in subsequent trials with mice models for PTSD as well as depression, as well as running the ketamine trial against a physiological model in which all they did was to give stress hormones. “[W]e only gave a tiny amount of the drug, and it lasted for weeks, and that’s not like anything you see with antidepressants.”
The hope, of course, is that the efficacy of the ketamine can be extended to help reduce the incidence of depression and PTSD in humans.
‘In particular, they may be of use to first-responders, emergency workers, and military personnel heading into exceptionally stressful situations.’
Source: Big Think