Stressed out rats drink more alcohol during PTSD study

PHILADELPHIA, Nov. 4 (UPI) -- University of Pennsylvania scientists say they have a better understanding of post-traumatic stress disorder after witnessing addictive behavior in rats.

In a study published in the journal Neuron, a rat model was used to explore the relationship between stress signaling and addictive substance use. Rats exposed to stress demonstrated a weakened alcohol-induced dopamine response, and drank considerably more than a control group.

"These effects happen at the minute level of potassium, chloride, and other ions moving across the neuron outer membrane via channels and transporters," researcher John Dani said in a press release. "In addition, by chemically blocking stress hormone receptors on neurons, we prevented stress from causing increased drinking behavior."

Rats in the experimental group were exposed to acute stress for 1 hour before researchers assessed their addictive behaviors 15 hours later. Feeding water in the experiment was laced with ethanol.

"The stress response evolved to protect us, but addictive drugs use those mechanisms and trick our brains to keep us coming back for more," Dani added.

Neurons in the experimental group were found to become more excitable over time, driving the rats to consume more ethanol-laced water. After the scientists introduced a chemical called CLP290, stress-altered circuitry returned to normal.

According to Dani, the findings may help develop treatment methods for individuals with PTSD, a mental disease characterized by impulsive behavior and often heavy substance abuse. The team is now developing compounds designed to normalize neuron activity.