Here's the normal pattern of dopamine release, it looks something like a roller coaster  because in biology, what goes up must come down. It could be food, sex, or even water when you're thirsty. So let's say you're hungry, dopamine starts rising, then you think about a burger and it rises more. When the burger is sizzling, dopamine is going way up, it peaks right about  your first bite, then you take some more bites, and it starts to drop off, and finally drops back  down to normal levels and you're full. This graph could also represent masturbating or having  sex, and the peak would be right about at orgasm. However, I really want to point out that the  experience of orgasm is probably driven by other neuro chemicals called opiate, not  dopamine. So dopamine drives you towards orgasm, but the feeling of orgasm arise from  something else. The rise of dopamine levels could also represent anything new or novel,  because dopamine loves novelty, and new car or just released movie, the latest gadget.  We're all hooked on dopamine, you can have a spike of dopamine just by ordering dessert.  Even though you haven't finished what's on your plate. Dessert is something new. In fact,  dopamine surging in your reward circuitry can override your feelings of what's called satiety or fullness. Regardless of what your rational brain might think about overeating or even watching porn. As with everything new, the thrill fades and dopamine levels drop. Now, back to the  Coolidge effect. So dopamine is what is behind the Coolidge effect. If you look at our little  graph, here, we have a female rat, number one, female rat number two and dopamine level,  what's happening is that the reward circuitry of the male is squirting less and less dopamine in each copulation with female number one, and then eventually the male can no longer  copulate because there's not enough dopamine. Dopamine is behind libido. Then you drop in  female number two, and the male gets another squirt of dopamine that surges his libido and  he goes back to work. This is what's behind the Coolidge effect. And it's also why you click  onto new videos while you're watching porn to get another big squirt of dopamine with  something novel. Okay, let's give another nicknames a dopamine, let's call it the molecule of  addiction. It's because changes in your brain that lead to addiction caused by changes in  dopamine level, cocaine, alcohol, nicotine, they all feel different, but all of them flood the  reward circuitry with dopamine, all addictive chemicals and activities raise dopamine levels.  It's what makes them potentially addictive. Of course, you need continued use of the addictive substance or activity to cause physical changes that lead to addiction here's an odd thing.  We've mentioned it before. dopamine is released in response to expectations rather than  actual levels of pleasure. It's the drive to get it. It's the craving. But as I've mentioned, the  actual pleasure of eating or orgasm is probably opioids. Those are morphine, like chemicals  being released in the brain. Dopamine is wanting it. opiates, and liking it. Addictions are  basically chasing after dopamine. So what happens is the addiction is wanting more, but liking it less. Speaking of wanting and the power of the reward circuitry, here's an experiment, we  have a rat and you see there's a wire and then there's this electrode does actually go into the  reward circuitry of the rat, and the rat has its little paws on a lever, and whenever it hits that  lever, it sends just enough electricity to the reward circuitry to stimulate it. Now, what will  happen is this rat will just keep hitting the lever and hitting the lever 1000s of times an hour  until it drops. It won't stop to eat, sleep, have sex or even take care of the pups. It'll give up  everything just to press that lever. As we know this behavior is not unlike some serious drug  addicts. Here's another experiment. They take the same rat and they have an electric grid  between the lever and the rat. So the rat has to feel painful shock and it's a little paws to go  over to the lever and press it well. The rat will actually cross the bridge and enjoy the shock.  But if you take the rat and put an electric grid between them and food, they will not cross the  electric grid. They will not undergo shocks to eat food. They would rather starve. Here's more  experiment to show you the power of dopamine in your reward circuitry. If you take rats and  block their dopamine, they have absolutely no motivation. They'll not even eat. They won't 

walk over to the food dish and they'll starve to death but they still like food. If you drop food  into their mouths they eat it and show little rat smiles. They just have no motivation to go get it they lie around, they won't have sex either. The male rat show no signs of libido. The key  point is you need the right level of dopamine to function normally. It does lots of important  jobs. Dopamine gives you that positive outlook good attitude keeps you motivated keeps you  happy. Incidentally, many psychological problems involve dopamine imbalances, including  addictions. Donate and help us make medical education universal, free state of the art and  available to every human being. For more such videos, join our Facebook group. Let's make  medical education universal free state of the art and available to every human being to enable the best medical facilities for everyone.



Última modificación: martes, 25 de octubre de 2022, 11:48