Although it can be found a relatively high number of BDSM psychological or psychiatric papers in the scientific literature, BDSM has not been practically studied from a biochemical or physiological point of view. In fact, even the biochemical works centered in the pleasure study are few. So, the only thing that I could do to write this paper was extracting ideas from studies which only share closeness to the BDSM topic: some of them deal with the pain, a little with the pleasure, and others don’t even deal with any of two subjects.
FI want to make clear that a lot of which I have written here are only hypotheses. Although these hypotheses have a scientific basis, I don’t claim them as immovable truths.
It is known that different sensations, both pleasurable and painful ones, prompt a first answer which is unspecific and similar. For example, both fear and sexual arousal, cause adrenaline release.
In a BDSM relationship, the femdom slave knows that the Dom worries about their integrity. Then, why that sub is reacting with fear if they actually know that their ebony femdom is going to look after them?
The amygdala is a part of the brain which is mostly activated by the fear. Experiments made in relation with phobias, have shown that the amygdala answers fear before the person is conscious of that fear.
The brain cortex also reacts towards fear, but it does it after the unspecific mechanism started by the amygdala has begun. The brain cortex is the part of the brain that allows us to be conscious about what is happening. On this way, during a scene, it might be that our body takes advantage of the adrenaline produced by the fear to increase the pleasurable sensations of sex, surrender, affection…
The fact that the amygdala seems to be involved in unconscious sexual desire, besides being involved in the fear, adds more reasons for the fear being able to lead to pleasure. Several studies seem to indicate this involvement of the amygdala in sexual desire.
Unconscious fear would cause an increase of adrenaline. The amygdala associates fear to excitement. Then, we would realize trough the brain cortex that we shouldn’t be afraid; but that couldn’t stop yet the adrenaline release process. This adrenaline would be added to the one release because of our sexual arousal, love, surrender, etc. The pleasurable feelings would increase its intensity by using the adrenaline produced by this irrational fear.
A hypothesis: endorphins released because of the pain would help to prompt an orgasm. However, studies have been made and it has been found an increase in the release of endorphins neither before, nor during the orgasm. There is an increase in the release of endorphins after the orgasm, which would explain the relax feeling subsequent to the coitus. But endorphins seem to make the orgasm difficult, so the pain would reduce the probability to get it.
On the other hand, endorphins are produced during the sexual attraction. It has been also observed that by putting together submissive and dominant animals, in the submissive ones there is a significant increase in the release of endorphins.
During the orgasm there is a significant increase of dopamine; actually the dopamine is perhaps the chemical of the sexual pleasure. Although the endorphins would make getting the orgasm more difficult, the pleasure with or without orgasm would be greater.
These days it isn’t clear if dopamine is actually the “pleasure neurotransmitter” or it is only the “desire neurotransmitter”. The production of dopamine during a pleasurable situation leads to want to repeat that situation. However, it is not clear if dopamine also is the cause of the pleasure.
It seems clear that dopamine lead to want to repeat the behavior which allowed its release.
Other studies seem to demonstrate that dopamine wouldn’t be only involved in pleasure production (or at least in the desire of repeating that situation which caused the pleasure); but it could also be the cause of the unpleasant psychological feeling which the pain induces in “standard conditions”.
Neurotransmitters carry out its effect by joining to receptors, a kind of proteins. A neurotransmitter activates certain receptors, and in this way it is produced the effect of that neurotransmitter. But one only kind of neurotransmitter can activate different kinds of receptors. It seems that the activation of some dopamine receptors is related to pleasure, whereas their merging to other kinds of receptor causes unpleasantness. The hypothesis would be that masochistic people had more receptors for the pleasure than for the pain.
I will only note that the humiliation and psychological “suffering” which subs are being subjected might lead ultimately to pleasure production by mechanisms very similar to the ones which lead from pain to pleasure.
Actually, it seems that unpleasant feelings can produce true pain. At least for the case of envy, it has been observed that it is able to activate the own routes of pain.
Nervous system is not formed by isolated groups of neurons being each one working independently from the others. On the contrary, all actions that take place in any area of the nervous system modify, in any way, the rest of the nervous system.
Painful stimuli activate nociceptores. Those receptors are specialized in starting the route which can lead to the painful sensation. But this activation not necessary leads to a painful experience. The brain cortex elaborates on the information coming from the nociceptores to give a certain perception of the pain.
This perception of the pain is influenced by former experiences and by the realm where the harmful stimulus is produced: As I have previously noted, dopamine causes a stimulus to be stored in our brain as pleasant and that makes to want to repeat that stimulus. This could lead to associate pleasure to some stimulus that formerly was generated joined to a pleasant one, although the first one should be an unpleasant feeling by itself.
Pain, similarly to fear, would activate nociceptores; these, would lead to the activation of unconscious mechanisms, like endorphin release; but it would be the processing in the brain cortex what really generated certain painful experience. There is an area in the brain which seems to be involved in the perception of the pain. Patients who have had this part of the brain extracted experience pain as a sensation, but not as a very unpleasant one.
Feelings are ultimately biochemical processes. And pain is the sensitive modality which is more influenced by emotional states and environmental circumstances. So, feelings (desire to make the dominant comfortable, to subdue to him; sexual attraction, love, attachment…) lead to generate brain routes which cross and modify pain and pleasure ones.
Both dopamine and endorphin, pleasure chemical substances, have a short action period and they stop early being released. So, the pleasure lasts only for a limited time. On the other hand, dopamine causes prolactin release. Prolactin is a hormone which decreases sex desire, as well as dopamine and endorphin release.
Oxytocin is released in response to both arousal and pain. In contrast to endorphins and dopamine, has a longer period of action. It is directly related to love and attachment and can compensate the slump of endorphins and dopamine.
So far, I have only spoken about a few neurotransmitters and hormones (adrenalin, dopamine, endorphins, prolactin, oxytocin and vasopressin). But that it’s a simplification of what really happens in our body in process such as pain. Actually what happens is a chain.
Other neurotransmitters greatly influence the process we have treated. For instance, serotonin influences pain, orgasm, mood… In fact, serotonin has such a wide range of actions that it is difficult to separate its influence in a concrete action.