VelocideX said:
A lot of people here are also assuming that serotonin release is responsible for the orgasm, and AFAIK its not. I don't have time to look, but if anyone finds any references on the neurochemistry of orgasms it would be worth posting
One of the primary effects of orgasm on your nervous system is the close tie between your sympathetic and parasympathetic nervous system. These two systems work entirely detatched from one another during all other actions: digestion, sleeping, moving, et cetera. The cross-over between whichever system is operating in the foreground is considerably slower at any time with the exception of orgasm; then, the switch is quite fast, and that itself throws your body for a loop.
As for serotonin, as stated, it is a very important neurotransmitter in the body; it has 25 +/- receptor proteins throughout your nervous system. Also, when serotonin attaches to a receptor, it doesn't let go. The molecules have to be pulled off in order to make whatever reaction is occuring within the postsynaptic cell cease. (On a side note, this is why MDMA is so abusive to serotonin receptors in the body... it wears them out like a maufugger.)
I'm not entirely certain, but unless I'm mistaken (which I probably am), orgasm only releases a relatively large quantity of both serotonin and dopeamine. Epenephrine/Adrenaline and norepenephrin/noreadrenaline I'm not so sure about. But those dopeamine and serotonin releases both end up stimulating the reward center in your brain, which coincides with the basic desire/necessity to procreate; speaking in terms of basic primal survival, orgasm is tied in with procreation, and procreation = propagation of the species = good.
Here's where it ties in: the drastic switch between your sympathetic and parasympathic nervous system at orgasm has just thrown your body for a loop; also, there has been a quantity of serotonin and dopeamine dropped into your system. Dopeamine is already giving you a pat on the back, but when you toss the really clingy serotonin into the mix, I'd imagine for a short while at least, your body is going to allow the serotonin to remain attached to the receptors for longer than usual.
When this happens, your body is going to realize that there is less free serotonin floating around your nerve synapses than normal, and the cell (are they cells or glands?) that store serotonin are going to release some to equal it out. When the dopeamine high-of-sorts wears off, your body will then realize there's too much serotonin, and start reclaiming it. But still, that's enough time for serotonin to take your body by storm for at least a few minutes, hence the potential for something of a short MDMA-like high/buzz.
How's that sound? I feel kinda smart after writing all of that.
~Decibel