system
Given the following post, respond as if you're commenting on Reddit:
human
What takes place in the brain and body when one ingests LSD and how does it lead to the experience of "tripping"?

From the placement on the tongue of a "hit" of LSD, can anyone walk me through the whole series of processes that occurs?
gpt
It goes from the tongue into the bloodstream, that's pretty simple.

Once in the brain, LSD works via activation of serotonin receptors in different parts of the cortex (specifically 2A receptors, although it appears other types may be involved in the effects as well). Many of these connections are inhibitory, but by inhibiting other inhibitory neurons, neurons which are not "supposed" to be firing begin firing. The visual effects (striped lines, spirals) can actually be computer modeled, as certain layers of the visual cortex contain neurons arranged in specific patterns.

The LSD is gradually metabolized and cleared from the blood, and the post-LSD effects result from downregulation - basically the neurons become less sensitive to hallucinogens and endogenous serotonin released naturally.