The real reason some people become addicted to drugs

Cogent explanation based on the distinction between liking and wanting.

In the 1980s, researchers made a surprising discovery. Food, sex and drugs all appeared to cause dopamine to be released in certain areas of the brain, such as the nucleus accumbens.

This suggested to many in the scientific community that these areas were the brain’s pleasure centers and that dopamine was our own internal pleasure neurotransmitter. However, this idea has since been debunked. The brain does have pleasure centers, but they are not modulated by dopamine.

So what’s going on? It turns out that, in the brain, “liking” something and “wanting” something are two separate psychological experiences. “Liking” refers to the spontaneous delight one might experience eating a chocolate chip cookie. “Wanting” is our grumbling desire when we eye the plate of cookies in the center of the table during a meeting.

Dopamine is responsible for “wanting” – not for “liking.” For example, in one study, researchers observed rats that could not produce dopamine in their brains. These rats lost the urge to eat but still had pleasurable facial reactions when food was placed in their mouths.

All drugs of abuse trigger a surge of dopamine – a rush of “wanting” – in the brain. This makes us crave more drugs. With repeated drug use, the “wanting” grows, while our “liking” of the drug appears to stagnate or even decrease, a phenomenon known as tolerance.

Source: The Conversation

Ta-Nehisi Coates to Chris Hayes: why Donald Trump really is a white supremacist

‘I think if you own a business that attempts to keep black people from renting from you; if you are reported to say that you don’t want black people counting your money; if you say—and not even reported, just come out and say—that someone can’t judge your case because they are Mexican; if your response to the first black president is that they weren’t born in this country, despite all proof; if you say they weren’t smart enough to go to Harvard Law School, and demand to see their grades; if that’s the essence of your entire political identity you might be a white supremacist, it’s just possible. …’

Source: Quartz

Scientists Link ‘Cat’ Parasite to Common Neurological Disorders

‘A new study shows that Toxoplasma gondii—a brain parasite often transmitted to humans by cats—triggers various changes in the human brain which potentially allow the pathogen to exacerbate several pre-existing neurological conditions. It’s a worrisome finding given that nearly one in ten Americans may be infected with the parasite, but more work is needed to assess T. gondii’s full impact on human health.

The new research, published recently in Scientific Reports, links T. gondii with several brain conditions, including Alzheimer’s, Parkinson’s, epilepsy, and even some cancers. The research, which involved 32 scientists across 16 institutions in the US, UK, Canada, and Australia, identifies key vulnerabilities in the human brain that enable the parasite to alter the course of a disease, and potentially make it even worse. The findings could eventually serve as a guide to help scientists design medications and interventions to repair and prevent neurological damage inflicted by T. gondii on the human brain…’

Source: Gizmodo