The knockout: when your brain goes offline...

The sweet science, also known as boxing, is a combat sport with roots that go deep into ancient history. However, the word sport is misleading; as they say in the boxing world, "you play sports, you don't play boxing." Pugilists use their fists to punch each other until the scheduled rounds end, the referee stops the fight (TKO), or one of them gets knocked out and is not able to get up before the 10-count is over. Among the rules: no punches to the back of the head (rabbit punches) or below the belt line.

Boxing can be brutal, and the knockout is a spectacle that brings eyes to the sport. But what happens during a knockout? Physiologically, what happens to the brain that makes you conscious one moment, unconscious the next, and conscious again the following moment?

Researchers argue different hypotheses to explain what happens. 

One theory is mechanoporation: pore formation in a neuronal cell membrane caused by mechanical forces. Meaning, a punch can deliver enough force to the brain that it causes neuronal axons to stretch until a pore develops in the membrane. They argue that the reason you go out is because the pores in the cerebral cortex block action potentials. Once the pores reseal, which can take minutes, you wake up (Hånell & Rostami 2020). It's not confirmed nor agreed to where the exact location this happens. Some argue its the ascending reticular activating system in the brainstem, which keeps you awake. 

One theory is mechanoporation: pore formation in a neuronal cell membrane caused by mechanical forces. In other words, a punch can deliver enough force to the brain that it causes neuronal axons to stretch until a pore develops in the membrane. Researchers argue that the reason you go out is that the pores in the cerebral cortex block action potentials. Once the pores reseal, which happens within minutes, you wake up (Hånell & Rostami, 2020). However, mechanoporation hasn't been proven yet, since the evidence so far comes from animal studies and computer models. Researchers also haven't agreed on exactly where this happens. Some argue it's the ascending reticular activating system in the brainstem, which keeps you awake.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7649325/