image: This is a model underpinning the effects of metformin on depressive symptoms in mice fed a HFD. view more
Credit: Zemdegs et al., JNeurosci (2019)
The antidiabetic medication metformin reduces anxiety-like behaviors in male mice by increasing serotonin availability in the brain, according to a study published in JNeurosci. These findings could have implications for the treatment of patients with both metabolic and mental disorders.
People with diabetes have an increased risk for mood disorders such as depression. Although the mechanisms underlying the relationship between insulin resistance -- the precursor to diabetes -- and depression are not known, studies suggest the neurotransmitter serotonin may be the culprit.
In mice raised on a high fat diet, Bruno Guiard and colleagues demonstrate that the insulin-sensitizing drug metformin reduces levels of amino acids that impair the entry of tryptophan in the brain and thereby limit its conversion into serotonin. The drug's antidepressant-like effects were accompanied by improved neurotransmission in the hippocampus. The researchers achieved similar effects by reducing the amount of so-called branched chained amino acids in the diet.
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Manuscript title: Metformin promotes anxiolytic and antidepressant-like responses in insulin-resistant mice by decreasing circulating branched-chain amino acids
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About JNeurosci
JNeurosci, the Society for Neuroscience's first journal, was launched in 1981 as a means to communicate the findings of the highest quality neuroscience research to the growing field. Today, the journal remains committed to publishing cutting-edge neuroscience that will have an immediate and lasting scientific impact, while responding to authors' changing publishing needs, representing breadth of the field and diversity in authorship.
About The Society for Neuroscience
The Society for Neuroscience is the world's largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 37,000 members in more than 90 countries and over 130 chapters worldwide.