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The Neuroscience of Sub Space in BDSM - Endorphins, Noradrenaline and Serotonin

This coveted state of bliss and euphoria in BDSM scenes may actually be different mental states

Nucleus raphe magnus of a rat, showing neurons containing noradrenaline (green) and serotonin (red)
Nucleus raphe magnus of a rat, showing neurons containing noradrenaline (green) and serotonin (red)

In the BDSM community, submissive space or sub space is a special state of bliss that is achieved by the submissive or bottom partner during a Dominance/submission (D/s) scene or sadomasochistic play. This mental state is reached by means of the pain produced by impact play (spanking, flogging, etc.) or bondage. In other occasions, sub space does not involve pain, but the emotions and mental manipulation resulting from masterful Dominance and unwavering submission.


It is commonly assumed that sub space is a single stated mediated by the release of endorphins and their opioid-like effect in the brain. However, the fact that it can be achieved through different means should alert us that it is not just one state but a collection of different altered states of consciousness, probably mediated by different neurotransmitters and brain areas. In previous articles, I have pointed out that some of the beliefs about sub space are supported more by myths than by actual scientific evidence.


Unfortunately, sub space is often followed by sub drop, its mirror image. Sub drop a negative emotional state of dysphoria, sadness, withdrawal, physical unease and even depression experienced immediately after a BDSM scene or several days afterward.


In this article, I propose here that there is not just one sub space but several, with distinctive characteristics. I need to emphasize, however, that there is almost no scientific research done on masochists. There is also very little research on the endorphin high and other altered states of consciousness produced by extreme exercise or by pain. Therefore, what I say here is speculative. It is based on my knowledge of the neurophysiology pain and emotions. I also draw parallels between the effects of drugs and the behavior of bottoms and submissives during BDSM scenes.


Noradrenergic sub space

The main natural response to pain is the fight-or-flight response. It consists of the activation of the hypothalamic-pituitary-adrenal (HPA) axis: the hypothalamus is a part of the brain that releases corticotropin-releasing factor (CRF or CRH) into the pituitary gland, located under the brain, which in turn releases adrenocorticotropic hormone (ACTH) into the blood, triggering the release of the stress hormones cortisol and adrenaline from the adrenal glands located over the kidneys. Adrenaline activates the sympathetic system, increasing the heart rate, switching blood circulation from the viscera to the periphery, and promoting muscular activity.


At the same time, inside the central nervous system there is a parallel activation of pathways that use noradrenaline as a neurotransmitter. Noradrenaline (or norepinephrine) is a similar compound to adrenaline (or epinephrine), it just lacks a methyl group (-CH3) attached to the amino (-NH2) terminus of adrenaline. While adrenaline is a hormone in the blood, noradrenaline is a neurotransmitter at some synapses in the brain. One important neuronal pathway that uses noradrenaline (noradrenergic pathway) goes from three noradrenergic nuclei of the brainstem (A5, A7, and the locus coeruleus or A6) down to the spinal cord. There, noradrenaline activates alpha-2 adrenergic receptors, producing an inhibitory action that suppresses incoming pain signals in the sensory nerves. This decreases pain (analgesia). Other noradrenergic pathways in the brain go from the brainstem to the cerebral cortex, activating it to increase alertness. Another noradrenergic pathway goes to the hypothalamus, activating the HPA axis. This way, noradrenergic activation in the brain is linked to sympathetic activation of the body, the stress response.


In BDSM, when the bottom partner goes into this noradrenergic state, she screams, struggles, stomps and laughs. At the same time, her pain thresholds go up and she becomes more tolerant of spanking and other forms of pain. Therefore, this sub state is characterized by analgesia, mild euphoria, outward-directed attention, and high interaction with the Top.


It is important to note that while the fight/flight response is considered a stress reaction, this is not necessarily a bad thing. Some forms of stress (eustress or good stress) are healthy and sought by many people. Just think of roller-coasters, horror movies and dangerous sports. A certain amount of eustress may be necessary for good health and can counter the nefarious effects of distress (bad stress). I think that BDSM is a form of eustress.


The noradrenergic sub space is similar to the effect of stimulant drugs like cocaine and amphetamines These drugs act by increasing the availability of noradrenaline and dopamine at some key brain areas, particularly the pathway linking the ventral tegmental area (VTA) to the nucleus accumbens. This is known as the pleasure pathway, but it actually mediates motivation and craving.


Endorphin sub space

This sub space also produces analgesia (decreased pain), but in almost all other aspects is the opposite of the noradrenergic sub space. In it, the heart rate goes down, and activity and alertness decrease.


The release of endorphins that leads to euphoria and analgesia is not into the blood, but occurs in some specific brain areas. The pain inhibition is driven by a pathway connecting the periaqueductal gray area in the middle of the brain with the nucleus raphe magnus in the brain stem, and then down to the spinal cord to block incoming pain signals.


There are reciprocal inhibitory connections in the brain stem between the nucleus raphe magnus (which drives endorphin release) and the noradrenergic nuclei (A5, A7 and nucleus coeruleus), so that when the endorphin system gets activated, the noradrenergic system gets inhibited, and the converse. While the noradrenergic system mediates fight/flight, the endorphin system is related to freezing behavior.Freezing is a response to imminent danger alternative to fight-or-flight. Immobility helps prey to escape predators by relying on camouflage. However, freezing also happens when the animal cannot generate a successful behavior - it doesn't know what to do. It's "heads I win, tails you lose". This is not a pleasant state. It's not accompanied by the euphoria that we normally associate with endorphin release. Repeated freezing from unavoidable stress leads to learned helplessness, a dysfunctional state that decreases learning, reduces immune activity and produces several other negative responses. However, I don’t think that learned helplessness is a problem in BDSM because the submissive is actually in control because she has chosen to be in the scene and can stop it by using a safeword or other safety devices. Where learned helplessness is a real problem is in non-consensual, abusive situations in which control is taken away from the victim. As long as the BDSM scene is consensual, the state of defeat of the submissive is illusory.


The endorphin sub space is similar to the effect of opioid drugs - like morphine or heroine - because endorphins activate the same receptors as these drugs: the mu and delta opioid receptors. Endorphins also produce the release of dopamine in the nucleus accumbens in the pleasure pathway, the one activated by addictive drugs. Therefore, one may wonder if continuously going into the endorphin state may not be similar to taking opioid drugs. However, unlike morphine, endorphins are rapidly degraded by peptidase enzymes in the brain. Hence, the body has its own safety mechanisms that make the endorphin high less dangerous than taking opioid drugs.


A bottom in the endorphin sub space becomes dreamy, with a calm form of euphoria. He is in an emotional mist, stops screaming and struggling, and becomes less alert of his surroundings. The unresponsiveness of the bottom in this state can be risky. Many people become non-verbal. The Top partner needs to be aware of this and not rely exclusively on safewords to dial down or stop the pain. Often, the bottom will plead for the beating to go on. She doesn’t want to leave that mental state - which is why at some people call it the forever place.


Serotonin sub space

This is the sub space that is properly named as such, because is induced by submission and not by pain.


Surrender, obedience, discipline, service and other strong intimate interactions with the Dominant likely lead to the release in the brain of oxytocin and vasopressin, which are the neuropeptides that mediate bonding. This state is similar to that produced by the drug MDMA (ecstasy or molly), which increases bonding, intimacy and affection. Since MDMA increases serotonin and dopamine at brain synapses and activates some serotonin receptors, this sub space may be driven by serotonin release in the brain. There is also evidence that the bonding effects of MDMA are due to the release of oxytocin in the brain.


Serotonin produces positive mood and counters depression. However, it has mixed effects on pain because some serotonin receptors in the spinal cord increase while other decrease pain. The same goes for dopamine, which can increase or decrease pain depending on the emotional state of the individual.


Whereas the noradrenergic and endorphin sub spaces are mutually exclusive, it is possible that the serotonin sub space can combine with them to produce mixed effects.


It is also clear that the noradrenergic, dopaminergic and serotonergic neurotransmitter systems vary a lot between individuals. That is why it is so difficult to fine-tune antidepressant medication to each person. Therefore, sub spaces are going to vary a lot from individual to individual.


Sub drop

There seem to be two types of sub drop.

  • The first type of sub drop happens right after a BDSM scene. It is likely the consequence of coming down from the fight/flight noradrenergic reaction. After a strong activation of the sympathetic system (the one that releases adrenaline into the blood) the parasympathetic system kicks in, decreasing the heart rate and cutting blood circulation to the periphery. The result is that the bottom feels cold, tired and emotionally exhausted. A blanket, lots of cuddles and emotional support are the best solution.

  • The second type of sub drop occurs about two days after the BDSM scene. It is similar to withdrawal from MDMA. It may be the result of the serotonergic or the endorphin sub space. It is much harder to address, because it creeps in long after the scene is over, when the Top is no longer available for emotional support. It may even last several days. The best way to address it is to be ready for it and have in place an emotional support system (friends, chocolate, a good movie, etc.).


Take-home message

Things in a BDSM scene are not as simple as going into sub space and come out of it a happier person. The human brain is incredibly complicated; we are just beginning to understand it. By inflicting lots of pain, or messing with strong emotions like shame, guilt and submission, we are giving our minds some extreme challenges. It is hard to predict what is going to happen. The best course of action is to go slowly, pay a lot of attention to your body, and find the path that works best for you.


An accomplished Top is not one who has perfected techniques so that they are going to work with anybody, but one who has learned to accurately read the body language of the bottom and knows how to adjust the scene accordingly.


With special thanks to GlassHummingbird from Fetlife, who taught me some of the things I wrote in this article.


Copyright 2022 Hermes Solenzol. Unauthorized duplication prohibited. If you cite parts of this article, please post a link.

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