Mice can provide clues to winter depression

Friday, May 8, 2015 (HealthDay News)-Researchers believe they have identified the responsible part of the brain Seasonal affective disorder (sad).

SAD, which affects 4 to 6 percent of Americans, is a type depression It happens during the winter. It is believed that the cause is the lack of sunlight in that season.

In a mouse experiment, biologists at Vanderbilt University said they tracked SAD to a small area of ​​the midbrain called the dorsal raphe nucleus.The mouse is often used for studying depression In humans.

In mice and humans, the dorsal raphe nuclei contains many of the neurons that control brain levels. Serotonin, Mood-related chemicals.High levels of serotonin are associated with feeling happy, low levels are associated depression..

Researchers have also found evidence that the season in which people are born can affect the activity levels of neurons in the dorsal raphe nucleus.

They divided the mice into three groups: one group was born and raised in a summer-like cycle of 16 hours of light and 8 hours of darkness, and the other group was 12 hours of light and 12 hours of darkness. Born and raised in a cycle like spring in the dark. The third group was born and raised in a winter-like cycle of 8 hours of light and 16 hours of darkness.

Mice born in the summer photoperiod had lower levels depressionResearchers have discovered more like behavior than those born in the spring / autumn or winter light cycle.

Also, mouse serotonin-producing neurons delivered during the summer photoperiod fired faster than neurons born during the spring / autumn or winter photoperiod. Mice born in the summer photoperiod also had high levels of serotonin.

When scientists switched summer-born mice to the winter light cycle, their serotonin-producing neurons fired at an increased rate for several months until adulthood.

“This has shown that early seasonal photoperiods can have permanent effects on serotonin neurons. If such effects occur in humans and last for a long time, it is a birth control of SAD risk. May contribute to the season, “said researcher Douglas McMahon, a university news release. He is the chair of Vanderbilt’s Biological Sciences.

However, it is not clear whether the results apply to humans, as studies with animals often do not give similar results to humans.

This study was published in the journal on May 7th. Current biology..

–Robert Preidt

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Source: Vanderbilt University, News Release, May 7, 2015

Mice can provide clues to winter depression

Source link Mice can provide clues to winter depression

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