Cocaine withdrawal: Emotional 'brakes' stay on after cocaine wears off

September 10, 2012

Washington State University researchers have found a cellular mechanism that contributes to the lack of motivation and negative emotions of a cocaine addict going through withdrawal. Their discovery, published in the latest Proceedings of the National Academy of Sciences, offers a deeper look into the cellular and behavioral implications of addiction.

Bradley Winters, lead author of the PNAS paper and a freshly minted WSU doctor of neuroscience, says he, his major advisor Yan Dong, and colleagues at WSU, the University of Pittsburgh and the European Neuroscience Institute focused on cells that produce a signaling molecule called cannabinoid receptor 1, or CB1. Its main function is regulating the communication between nerve cells related to the functions like memory, motor control, perception, mood and appetite. Those same functions are affected by THC, the cannabinoid in its namesake cannabis, or marijuana.

"These receptors are not here just to make marijuana fun," says Winters. "Their main function is changes in how nerve cells communicate with each other."

The researchers studied the CB1 cells by producing a line of mice in which the cells that make CB1 were labeled fluorescently. The researchers could then identify the cells and target them with glass pipettes 1/100th the width of a human hair and record electrical currents they use to communicate with other .

The CB1 cells act like brakes, slowing down activity in a brain region called the nucleus accumbens, which governs emotion and motivation.

"Cocaine causes profound in the nucleus accumbens, but no one has ever looked at this type of cell, and these cells are important because they help organize the output," says Winters.

The researchers found that cocaine increases the excitability of the CB1 cells, in effect stepping on the brakes of emotion and motivation. When an addict is high on cocaine, the brakes are struggling to slow things down. The problem is, they stay on even when the cocaine has worn off.

"As you do cocaine, it speeds everything up, pushing you to a highly rewarding emotional state," says Winters. "It is kind of like going down a steep hill so you have to start riding that brake really hard. But then after the cocaine wears off and the hill levels out, you're still riding that brake just as hard. Now you're going down a regular, low-grade hill but you're going 2 mph because your foot is still jammed on the brake."

The result is a drag on the emotions and motivation of an addict in withdrawal—a drag that could be linked to sluggish activation of the .

"That state is like, 'I feel terrible and I don't want to do anything,'" says Winters. "You have the high and the crashing low and this low that you feel is what brings you back to the drug because you want to feel better and the drug is the only thing you feel motivation for."

Explore further: How the brain puts the brakes on the negative impact of cocaine

Related Stories

How the brain puts the brakes on the negative impact of cocaine

January 11, 2012
Research published by Cell Press in the January 12 issue of the journal Neuron provides fascinating insight into a newly discovered brain mechanism that limits the rewarding impact of cocaine. The study describes protective ...

Receptor limits the rewarding effects of food and cocaine

July 12, 2011
(Medical Xpress) -- Researchers have long known that dopamine, a brain chemical that plays important roles in the control of normal movement, and in pleasure, reward and motivation, also plays a central role in substance ...

Cocaine decreases activity of a protein necessary for normal functioning of the brain's reward system

April 22, 2012
New research from Mount Sinai Medical Center in New York reveals that repeated exposure to cocaine decreases the activity of a protein necessary for normal functioning of the brain's reward system, thus enhancing the reward ...

Recommended for you

Exosomes are the missing link to insulin resistance in diabetes

September 21, 2017
Chronic tissue inflammation resulting from obesity is an underlying cause of insulin resistance and type 2 diabetes. But the mechanism by which this occurs has remained cloaked, until now.

Thousands of new microbial communities identified in human body

September 20, 2017
A new study of the human microbiome—the trillions of microbial organisms that live on and within our bodies—has analyzed thousands of new measurements of microbial communities from the gut, skin, mouth, and vaginal microbiome, ...

Study finds immune system is critical to regeneration

September 20, 2017
The answer to regenerative medicine's most compelling question—why some organisms can regenerate major body parts such as hearts and limbs while others, such as humans, cannot—may lie with the body's innate immune system, ...

Immune cells produce wound healing factor, could lead to new IBD treatment

September 20, 2017
Specific immune cells have the ability to produce a healing factor that can promote wound repair in the intestine, a finding that could lead to new, potential therapeutic treatments for inflammatory bowel disease (IBD), according ...

As men's weight rises, sperm health may fall

September 20, 2017
(HealthDay)—A widening waistline may make for shrinking numbers of sperm, new research suggests.

New model may help science overcome the brain's fortress-like barrier

September 19, 2017
Scientists have helped provide a way to better understand how to enable drugs to enter the brain and how cancer cells make it past the blood brain barrier.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
1 / 5 (1) Sep 10, 2012
Who cares about imaginary brakes being stepped on so long as the coke hasn't been.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.