It was 1846, when a young man lay on an operating table as doctors were ready to perform a surgery to remove a tumor from his neck. Then came a strange-smelling vapor. It was mix of ether and oil, and it filled the room. The man lying on the operation table did not flinch or cry out, there was no pain. When he woke up, it was as if nothing had happened. This was the day that marked the dawn of general anesthesia. It was on this day today in 1846, that surgical anesthetic WTG Morton conducted the first successful demonstration of ether. Thus, this day is observed as the World Anesthesia Day. Nearly two centuries later, scientists are still trying to figure out what actually happens to the brain when we under go anesthesia?The Mind Under AnesthesiaAnesthesia doesn’t simply make a person “fall asleep.” It creates a state where the brain disconnects from conscious awareness while vital body functions remain stable.When the drug enters your bloodstream, it alters how the nerve cells in the brain communicate. Usually, a billion of neurons send and receive signals rapidly, and forms networks responsible for thinking, feeling, and awareness. However, when anesthesia enters the body, these signals slow down or stop and it disrupts the communication between key regions, such as the cortex, which is responsible for handling thought and sensory perception, and the thalamus, which is responsible for processing information from the body. Furthermore, the brainwave pattern, which usually looks fast and varied on an EEG, shift into slower and larger waves. The mind actually "tunes out" losing its ability to form memories, sense time, or even to process pain. While anesthesia is designed to create total unconsciousness, it’s a delicate balance. Too little, and traces of awareness can slip through, a phenomenon known as accidental awareness, where patients recall sounds, sensations, or pressure during surgery. It’s rare but can be distressing.However, too much can make the brain enter a state of extreme suppression. In such cases, EEG readings show almost flat patterns, indicating that neurons have gone quiet. This can also raise the risk of confusion or cognitive issues after surgery, especially among older adults. In most people, the fog clears within hours, but some experience short-term problems with memory or focus, known as post-operative cognitive dysfunction. In older patients, this sometimes extends into delirium — temporary disorientation or hallucinations caused by lingering changes in brain activity.How Does The Mind Wake Up?You do not immediately wake up, but the mind reboots in layers. High-order functions like reasoning and self-awareness are the first to recover, then attention, coordination, and reaction time. Studies show that as the anesthetic wears off, brain activity gradually reconnects across different regions. Certain rhythms that dominate during unconsciousness fade, replaced by faster, more complex patterns as the brain resumes its normal communication. It’s as though the mind is reassembling itself, piece by piece.Anesthesia does not just turn the brain off, but reshapes consciousness, suspending awareness, while also preserving life.