In the 30-second period after the animal's hearts stopped beating, they measured a sharp increase in high-frequency brainwaves called gamma oscillations.
These pulses are one of the neuronal features that are thought to underpin consciousness in humans, especially when they help to "link" information from different parts of the brain.
In the rats, these electrical pulses were found at even higher levels just after the cardiac arrest than when animals were awake and well.
Dr Borjigin said it was feasible that the same thing would happen in the human brain, and that an elevated level of brain activity and consciousness could give rise to near-death visions.