IMHO - The Addiction Article Is Pseudoscience - The Video Is Closer To The Truth

MIT |  Cocaine, opioids, and other drugs of abuse disrupt the brain’s reward system, often shifting users’ priorities to obtaining more drug above all else. For people battling addiction, this persistent craving is notoriously difficult to overcome — but new research from scientists at MIT’s McGovern Institute for Brain Research and collaborators points toward a therapeutic strategy that could help.

Researchers in MIT Institute Professor Ann Graybiel’s lab and collaborators at the University of Copenhagen and Vanderbilt University report in a Jan. 25 online publication in the journal Addiction Biology that activating a signaling molecule in the brain known as muscarinic receptor 4 (M₄) causes rodents to reduce cocaine self-administration and simultaneously choose a food treat over cocaine.

M₄ receptors are found on the surface of neurons in the brain, where they alter signaling in response to the neurotransmitter acetylcholine. They are plentiful in the striatum, a brain region that Graybiel’s lab has shown is deeply involved in habit formation. They are of interest to addiction researchers because, along with a related receptor called M₁, which is also abundant in the striatum, they often seem to act in opposition to the neurotransmitter dopamine.

Drugs of abuse stimulate the brain’s habit circuits by allowing dopamine to build up in the brain. With chronic use, that circuitry can become less sensitive to dopamine, so experiences that were once rewarding become less pleasurable and users are driven to seek higher doses of their drug. Attempts to directly block the dopamine system have not been found to be an effective way of treating addiction and can have unpleasant or dangerous side effects, so researchers are seeking an alternative strategy to restore balance within the brain’s reward circuitry. “Another way to tweak that system is to activate these muscarinic receptors,” explains Jill Crittenden, a research scientist in the Graybiel lab.

At the University of Copenhagen, neuroscientist Morgane Thomsen has found that activating the M₁ receptor causes rodents to choose a food treat over cocaine. In the new work, she showed that a drug that selectively activates the M₄ receptor has a similar effect.

When rats that have been trained to self-administer cocaine are given an M₄-activating compound, they immediately reduce their drug use, actively choosing food instead. Thomsen found that this effect grew stronger over a seven-day course of treatment, with cocaine use declining day by day. When the M₄-activating treatment was stopped, rats quickly resumed their prior cocaine-seeking behavior.  Fist tap Dale.