Scientists study binge-drinking rats to better understand mechanisms of addiction


Alcoholism and other addictions led to changes in the brain, such as over-activity of stress-related circuits and a weakening of other circuits that act as a “brake” on emotional reactions and impulsive behaviors. In an effort to understand the sequence of neural events by which these changes come about, researchers at The Scripps Research Institute studied binge-drinking rodents and found signs of cognitive impairment in rats similar to that seen in alcoholics.

The effect was observed in the animals with just a few months of intermittent alcohol access (three days per week).

Surprisingly, these impairments did not appear in rats that had 24/7 access to alcohol. Those animals drank moderate amounts every day, and did not escalate their drinking over time.

Researchers linked the rats’ impairment to a small group of neurons that inhibit “executive control” functions in the brain’s prefrontal cortex. These neurons were unusually active in the periods between drinking binges — and the more active they were, the more the rats drank when they next had access to alcohol.

The finding, if confirmed in human studies, could lead to better treatments, preventive approaches, and diagnostic tests for problem drinking and possibly other addiction behaviors. —

Findings appear in the

Proceedings of the National Academy of Sciences.

News release at

Laparoscopic surgery reduces pain

Kidney-cancer patients who underwent an emerging, minimally invasive surgical technique called Laparo-Endoscopic Single-Site Surgery (LESS) experienced less postoperative pain than those who received traditional laparoscopic surgery.

LESS is performed with one small incision in the naval through which all surgical tools are inserted to reach the tumor. Patients undergoing traditional laparoscopy receive four to six abdominal incisions.

A UC San Diego School of Medicine study compared LESS with traditional multiport laparoscopy in 74 patients needing either complete or partial kidney removal for malignancy. After surgery, patients rated the LESS surgery as 40 percent less painful than traditional laparoscopic surgery; a finding supported by a 50 percent reduced need for narcotic pain medication. —

Study results appear in the journal

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Insight into high cholesterol and heart disease

Atherosclerosis — the hardening of arteries that is a primary cause of cardiovascular disease and death — has long been presumed to be the consequence of complicated interactions between overabundant cholesterol and resulting inflammation in heart and blood vessels. But the relationship is not exactly what it appears, according to a UCSD School of Medicine study.

Within arterial walls are immune system cells called macrophages (Greek for “big eater”) whose function is to consume other cells or matter identified as foreign or dangerous. In the process they consume, metabolize, and eliminate the other cell’s store of cholesterol.

But when macrophages fail to properly dispose of excess consumed cholesterol, it accumulates inside them as foamy lipid (fat) droplets. At this point the cells, now identified as “macrophage foam cells,” initiate a cascading effect that ultimately launches an inflammatory response that can lead to heart disease. —

Findings appear in the journal

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Lynne Friedmann is a science writer based in Solana Beach.