Contentment with "little" things The power of dopamine and our reward circuitry are seen in classic experiments done on rats. Consider what happens when sadistic scientists put a starving rat on one side of a grid with electric current running through it and food on the other side.
The rat will not cross the pain-producing grid. She will ignore food, even if starving, or abandon her unweaned pups just to tap that lever until she drops.
Humans implanted with similar electrodes decades ago experienced a constant urge to tap their levers, as well as intense sexual arousal—but not pleasure or orgasm itself.
They also reported an undercurrent of anxiety. Despite the obvious differences between rats and humans, rats have been called "guiding flashlights" for understanding the primitive mechanisms of our own brain. Sexually-satiated male rats take up to fifteen days to recover their full desire for sex although they can get it up long before they are back to full steam. Female rats also show evidence of a similar cycle in the form of predictable surges of prolactin after vigorous copulation, whether or not they become pregnant.
A shadow version of this prolactin cycle has now been detected in women , and may be connected with post-sex mood swings in some women. Research also shows that male rats experience a reduction in testosterone receptors for up to a week within their reward circuitry. Hormones and neurochemicals dock with receptors on the nerve cells.
In this case, fewer receptors mean less sensitivity to circulating testosterone. The result is that the reward circuitry pumps out less dopamine.
It's like the reward circuitry's batteries are low. If this happens in females, it would also reduce their sexual desire. Low testosterone or decreased sensitivity to it is associated with irritability and anger. Serotonin and endorphin levels also rise in the reward circuitry of sexually-satiated rats. Most of us have heard that these are "happy neurochemicals," but in this part of the limbic system both function to put on the brakes instead of just producing warm, fuzzy feelings.
Keep in mind that sexual dysfunction is a major side effect of taking either antidepressants that raise serotonin or narcotics that mimic endorphins. When neurochemicals dampen your reward circuitry for a time, your relationship can suffer. See The Passion Cycle for an overview of this neurochemical cycle, and for more recent research see Men: Does Orgasm Give You a Hangover? Researchers have shown that ejaculation, even twice a week, shrinks the dopamine-producing neurons in the VTA, which reduces a male's response to the pleasure of morphine.
This also happens with repeated heroin use in both rats and humans. Scientists have also learned that amphetamine activates the exact same nerve cells as orgasm, urging the brain to "remember and repeat. Dopamine and the Coolidge Effect Humans, like virtually all mammals, are not naturally monogamous as in sexually exclusive , although many individuals are. This may not sound very romantic, but no mammals are sexually exclusive. A few, such as humans, are "socially monogamous.
It is therefore likely that our mating neurochemistry is set up to accomplish two goals. It encourages bonding so we co-parent. Yet there is also a conflicting program to push us out of those bonds—at least far enough to add a novel mate.
From chimps to rats, the same neurochemical events drive mammalian behaviors, and they are driving them to be promiscuous. Is it likely that Mr. Rodent are growing apart in their relationship? Could the excitement be gone from their marriage? Chimp spends too much money, or nags too much. Just like us, they have a subconscious program, triggered by mating, found in their limbic systems, which biology uses to urge them tire of their mates and move on to new mates. During the week or two that the hangover from orgasm lingers, our large, rational brain proposes logical reasons to explain our relationship disharmony.
But it may also be natural for both men and women to sour on a mate, to suddenly find a spouse unattractive, irritating, and wholly unreasonable. It may even be natural to become wholly unreasonable, and thus hasten the departure of a mate. Now, we know that all of you are wondering about that sure-fire way to jump-start male rats' flagging libido. Perhaps you can already guess.
All you have to do is introduce a new, receptive female. That may not be the answer you were hoping for…or perhaps it was! Have you ever heard of the "Coolidge Effect? Scientists have discovered that—after a frenzy of copulation—a male rat will lose interest in a female. The Coolidge Effect has been observed in every species tested, and not just in males.
Lady rodents prefer to seduce new guys, too. The Coolidge Effect just might play a role in human affairs as well. Marnia once talked with a man who had stopped counting at lovers. I lost interest in all of them sexually so quickly—and some of those women are really beautiful, too.
No dopamine surge, no interest. She is not perceived as "rewarding. The thrill is gone, and Partner No. As if by magic, your blues are gone, and you have that heady feeling of anticipation, that sense of uninhibited aliveness. This also has implications for understanding today's binging on Internet porn. Assuming we don't learn how to steer for lasting bonds by taming our limbic system, our reward circuitry will push us to do just what it evolved to do once our temporary honeymoon neurochemistry wears off.
We'll get less and less dopamine "reward" during sex with our current mate. Notice that this is similar to what occurs when people use drugs, play intense video games, binge on Internet porn, or gamble. They seek more and more stimulation to get the same high. In short, feelings of sexual satiety do not promote romance—which calls into question a lot of today's relationship advice about producing bigger, better and more frequent orgasms. The truth has been recognized for thousands of years.
Here's a poem from the ancient Greek Anthology. Once plighted, no men would go whoring. They'd stay with the one they adore, If women were half as alluring After the act as before. Back to our tale. Unlike rats, you have many dopamine-raising possibilities—from Internet porn, gambling and alcohol, to the dopamine agonists drug companies are producing to light a fire under slumbering libidos not recommended, due to risky side effects.
These "fixes" make you feel better briefly, but as far as your well-being goes, they are like eating junk food—a net loss. As biologist Robert Sapolsky observed, there is a price for blasting our reward circuitry too enthusiastically in our efforts to counter the blues.
Unnaturally strong explosions of synthetic experience and sensation and pleasure evoke unnaturally strong degrees of habituation Our tragedy is that we just become hungrier.
Your limbic system is not equipped to understand that there can be too much of a good thing. It just keeps rewarding you to do the same unrewarding things because they register as things that once served your ancestors. A "fix" just positions you for a continuous cycle of highs, more lows, and a search for more highs. Many of us spend much of our sex lives caught in this cycle—with no obvious way out. The neurochemical that binds couples together is oxytocin, the "cuddle hormone" or "bonding hormone.
Falling in love is associated with a soup of neurochemicals—like adrenaline, which makes your heart race, and, as we have mentioned, dopamine, which makes you crave your beloved, and low serotonin, which can make you obsessed with someone.
It also serves to bond us to our mate…at least long enough to fall in love with our child so that it has two caregivers for its long childhood and adolescence.
Friendships are also built on oxytocin, and can be quite deep bonds. Yet, what happens to friendships that turn into sexual relationships? Often things change for the worse. This change is an excellent example of the post-sexual satiation neurochemical shift, or hangover, kicking in. Oxytocin and dopamine are the yin and yang of bonding and love.
Dopamine furnishes the kick, oxytocin makes a particular mate appealing, in part by triggering feelings of comfort.
You need both acting on the reward circuitry at ideal levels to stay in love. In experiments, if scientists block either oxytocin or dopamine, mothers will ignore their pups. There's evidence that these two neurochemicals stimulate each other's release , so if one is low, it affects levels of the other. As sexual satiation plays havoc with dopamine, lovers can end up with a double-whammy effect on their precious emotional bonds.
As things go sour, something interferes with oxytocin's bonding effects. It's likely that it's temporary low dopamine, or reduced sensitivity to it. This is the secret that the ancient sacred-sexuality sages stumbled upon. Making love with lots of affection, without the dopamine-driven highs and lows of conventional sex, seems to keep neurochemical levels balanced.
There's some evidence that the more oxytocin you produce, the more receptive to it key nerve cells become. This is the opposite of dopamine. In addicts, dopamine receptors start to decrease as the nerve cells protect themselves from overstimulation. Addicts then need more and more of a drug more and more dopamine. Daily bonding behaviors can make your partner look better and better —at least to you. This is why daily affection, with less orgasm, can strengthen your bond with your mate.