It’s time for “Nerd News,” covering the most important news for your brain.

Here’s a quick rundown of this week in science . . .

1.  A genetic study found humans almost went extinct 900,000 years ago.  The estimate is there were only 1,280 of us left at one point.

2.  Here’s something you already knew:  A study found intense dreams can spill over into real life and affect you at work.  (Like that dream you had about the cutie in accounting, and now you feel oddly nervous around them.)

3.  In space news:  Japan’s version of NASA made a line of skincare products specifically for astronauts.  Skin tends to get pretty itchy and dry up there.

4.  In sexy grandma news:  A study found seniors who frequently get it on tend to stay sharper mentally.  Even people in their 90’s.

5.  And in other health news:  A study found laughter can literally heal a broken heart.  Laughing every day promotes the flow of oxygen, and expands heart tissue for people with heart disease.  So, more proof laughter really is the best medicine.