The latest edition of the Proceedings of the National Academy of Sciences has published a report that examines the happenings in a brain when it recovers from the effect of anaesthetics.
“It is remarkable indeed that we recover from anaesthesia the way we do,” says Alexander Proekt, a visiting fellow in Don Pfaff’s Laboratory of Neurobiology and Behaviour at Rockefeller University and an anaesthesiologist at Weill Cornell Medical College, both in New York. If, for example, you learned how to sing a particular song on on Sunday and on Monday, you have surgery, you wake up and still know how to sing that song.
Fascinated by the brain’s astonishing ability to recover normal function quickly after “significant perturbations” such as anaesthesia, Proekt and fell back on statistical analysis to investigate a hypothesis that as an anaesthetic washes out of the body, electrical activity returns the brain to its usual conscious patterns.
However, this journey from an anaesthetised state to full normal consciousness is not without its bumps. “Recovery from deep anaesthesia is not a smooth, linear process,” says Proekt. A brain occupies many ‘way stations’ or states of activity on the way to full recovery,” say the researchers. These results may have implications for understanding how brain injury can disrupt someone’s ability to recover consciousness.
The unconscious brain recovers consciousness through an intrinsic process. “The anaesthetic is just a tool for severely reducing brain activity in a way in which we can control,” he says. The study also attempted to find out what happens to the brain during comas, brain injuries and neurological diseases. However, as the disruption to consciousness cannot be controlled in these scenarios, they were much harder to study. Suggests co-author and research associate Diany Paola Calderon: “In these scenarios it is possible that a pathway has shut down, or a brain structure that was key for full consciousness is no longer working.”