THE NEUROCHEMISTRY OF SEX

by Walter Last

Orgasm is generally regarded as the ultimate goal of recreational sex. Wilhelm Reich was the first scientist to describe the nature and purpose of the orgasm as a discharge of excess bio-energy with the additional liberation of feeling energy, and he also recognized the negative consequences of blocked sexual energies.

Unfortunately, in addition to exciting peaks, orgasms tend to produce powerful negative side-effects that are only now becoming better understood. This is due to predictable trends in hormonal activity which seem to be similar in all mammals to ensure certain evolutionary objectives, especially the wide mixing of gene pools and the safe raising of offspring. This is achieved with the following neurochemical changes.

The main players are dopamine, the reward hormone; prolactin, the hormone of satiation; oxytocin, the cuddle hormone, and levels of androgen receptors, which all powerfully affect our mood, our desire for intimacy, our perception of our mate, as well as our susceptibility to addictive activities and substances. These hormones can also have different but generally related functions.

Additionally the stimulant phenylethylamine (PEA) is involved, which is also present in cocoa and chocolate and elevates energy, mood and attention. PEA is produced in greater amounts when one is in love; conversely a deficiency (common in manic-depressives) causes unhappy feelings.

When we first fall in love we become bonded by rising PEA, oxytocin and dopamine levels When we are sexually aroused by close contact our dopamine level rises further and at the time of orgasm we have a dopamine brainstorm which one researcher compared to the effects of heroin on the brain. Dopamine is active in all addictions, even in people who have forgotten what sex is. Most of this activity is in the limbic system, the oldest part of the brain.

Dopamine Levels

EXCESS	DEFICIENT	"NORMAL"
Addictions	Addictions	Motivated
Anxiety	Depression	Feelings of well-being satisfaction
Compulsions	Anhedonia - no pleasure, world looks colorless	Pleasure, reward in accomplishing tasks
Sexual fetishes	Lack of ambition and drive	Healthy libido
Sexual addiction	Inability to "love”	Good feelings toward others
Unhealthy risk-taking	Low libido	Healthy bonding
Gambling	Erectile dysfunction	Healthy risk taking
Compulsive activities	No remorse about personal behavior	Sound choices
Aggression	ADD/ADHD	Realistic expectations
Psychosis	Social anxiety disorder	Maternal/Paternal love
Schizophrenia	Antisocial behavior

(From: http://www.reuniting.info/science/sex_and_addiction)

After orgasm dopamine levels fall sharply with the usual withdrawal symptoms. This reaction tends to be immediate in males and delayed in females. Also prolactin levels rise, and androgen receptors fall after orgasm. Low testosterone is associated with irritability and anger. In sexually-satiated rats it has been shown that serotonin and endorphin levels also rise, and this also decreases dopamine and raises prolactin levels. Oxytocin levels fall after conventional orgasm but remaining in close contact may help to counter this drop and sustain oxytocin levels.

Behavioral changes from this disturbed hormone equilibrium have been noticed for up to two weeks. During this time we may be more irritable, dissatisfied, anxious or depressed, and instead of seeing the good side of our mate, we may now be painfully aware of his or her shortcomings.
This is exactly the same process and length of time prolactin levels need to recover during withdrawal from cocaine.

Symptoms associated with excess Prolactin

WOMEN	MEN
Loss of libido	Loss of libido
Mood changes / depression	Mood changes / depression
Hostility, anxiety	Impotence
Headache	Headache
Menopausal symptoms, even when estrogen is sufficient	Infertility
Signs of increased testosterone levels	Decreased testosterone levels
Weight gain	Weight gain
Intercourse may become painful because of vaginal dryness

(From: http://www.reuniting.info/science/sex_and_addiction)

Initially, during the honeymoon period of our relationship, we remain strongly bonded by high oxytocin levels, and quickly overcome our hormonal blues by having more sex. Initially sex stimulates us to crave for more sex. This leads to rapid rises and falls in dopamine levels and corresponding rapid emotional fluctuations in our relationship. Later we become less and less interested in sex with our partner (perhaps because we subconsciously begin to associate him or her with the “lows” of the cycle, or perhaps because we grow tired of being used as a fix, and therefore feel less attraction), and now we try to prop up our dopamine level by becoming addicted to some kind of food or drug, or by becoming interested in a new sexual partner. Basically this type of behavior is the same for humans, primates, mammals and reptiles because it originates from the primitive part of our brain.

Further evidence of a lasting post-orgasm hangover comes from sexually exhausted male rats. The number of androgen receptors in the hypothalamus declines, reducing the effectiveness of testosterone and changing sexual behavior. These changes last for about seven days, corresponding to a lack of libido of the rats.

In addition to serving as a sexual brake, prolactin also affects our moods and behavior somewhat like a hormone of resignation. For example caged wild monkeys initially had high levels of the stress hormone cortisol but gradually prolactin levels rose as they became resigned to their fate. Prolactin levels were highest after seven months. With raised prolactin levels they do not mate, which looks like the same effect that we see in long-term relationships without close oxytocin-producing bonding.

The Coolidge-Effect

In experiments with rats it has been observed that after vigorous copulation with a new partner, male rats soon completely ignore this partner, but when a new female is introduced, they immediately are revitalized - at least sufficiently to become sexually active once more. This can be repeated again and again until the male rat is completely exhausted.

This phenomenon has been called the “Coolidge Effect” after an American president. On a visit to a farm his wife had been shown a rooster who could copulate with his hens all day-long day after day. She liked that idea and asked the farmer to let the president know about this. After hearing it, President Coolidge thought for a moment and asked: ”Does he do that with the same hen?” “No, Sir” answered the farmer. “Please tell that to Mrs. Coolidge” said the president (http://www.reuniting.info/science/coolidge_effect).

Not only has the Coolidge effect been observed in all tested male animals, but also in females. Female rodents for instance flirt more and present themselves more attractively when observed by new males than in the presence of males with whom they had already sex.

President and Mrs. Coolidge

Another experiment indicates that the cause of this effect may be a rush of dopamine. When rats were taught to pull a lever to stimulate their own reward center, they would forgo eating and copulating, and just continue to stimulate themselves until they were totally exhausted.

The Cuddle Hormone

The dopamine system is obviously designed to produce genetic variety by inducing us to mate with as many different partners as possible. There is, however, a hormone that counteracts the emotional rollercoaster effects of dopamine, and that is oxytocin, the cuddle-hormone. Oxytocin also counteracts fear, which is associated with high cortisol levels and stress, see chart below.

Oxytocin leads to strong pair-bonding. In pair-bonded animals mating, and with this the dopamine rollercoaster, stops with the rise of prolactin after successful fertilization, and now oxytocin ensures that both parents cooperate for the survival of their offspring. Humans could do the same, mate only to produce offspring and then abstain from sex. This might produce an emotionally stable relationship for life, but most of us would also find it utterly boring. Paramahansa Yogananda wrote this is exactly what his parents did (Autobiography of a Yogi).

The Benefits of Oxytocin

FEAR - CORTISOL	LOVE - OXYTOCIN
Aggression	Anti-stress hormone
Arousal, Anxiety, Feeling stressed-out	Feeling calm and connected, Increased curiosity
Activates addictions	Lessens cravings & addictions
Suppresses libido	Increases sexual receptivity
Associated with depression	Positive feelings
Can be toxic to brain cells	Facilitates learning
Breaks down muscles, bones and joints	Repairs, heals and restores
Weakens immune system	Faster wound healing
Increases pain	Diminishes sense of pain
Clogs arteries, Promotes heart disease & high blood pressure	Lowers blood pressure, Protects against heart disease
Obesity, Diabetes, Osteoporosis

(From: http://www.reuniting.info/science/sex_and_addiction)

The time-honored solution to this problem is loving sex without orgasm. This greatly helps to sustain oxytocin levels without producing emotionally disruptive high-low neurochemical cycles of orgasm, and it has been practiced in Indian Tantra, by the Chinese Taoists, and apparently by early Christians. In modern times it has been resurrected as Karezza, White Tantra and various forms of spiritual sex. It heals and holds relationships together rather than driving them apart as frequent orgasmic sex seems to do although, as we will see later, it is also possible to have bonding orgasmic sex.

For a wealth of articles on the hormonal aspects of our sexuality see: http://www.reuniting.info/science.