system
Given the following post, respond as if you're commenting on Reddit:
human
Why do we start to hallucinate if we don't sleep for days?

I have heard that people who stay awake for 4+ days start to go rather crazy. They might begin to hear things and even suffer visual hallucinations. What is the brain missing from sleep that causes this?
gpt
Long term insomnia has an effect on the sensitivity of neurotransmitters like GABA, seratonin, and neurepinephrine that would be down or up-regulated during sleep. The result is abnormal synaptic activity in certain parts of the brain. The results are unpredictable but can cause tremors, twitches, changes in attitude/behavior, and hallucinations among others. Basically, something in your visual cortex or thalamus is experiencing abnormal neuron firing resulting in random extraneous signalling that cause hallucinations.