Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.

  1. Brain

    Explainer: What is dopamine?

    Dopamine is a chemical messenger that carries signals between brain cells. It also gets blamed for addiction. And a shortage of it gets blamed for symptoms of diseases such as Parkinson’s.

  2. Brain

    Explainer: What is neurotransmission?

    When brain cells need to pass messages to one another, they use chemicals called neurotransmitters. This sharing of chemical secrets is known as neurotransmission.

  3. Health & Medicine

    Scientists Say: Bruxism

    Some people clench their jaw when their stressed. People who do it a lot may have bruxism.

  4. Health & Medicine

    Snot Science: A snotty setup

    We’ve got a video with a snotty experiment. Now we describe how you can do the same test yourself. Try it!

  5. Health & Medicine

    Snot Science: Results are nothing to sneeze at

    We tested a lot of snot, but now we need to figure out what our data mean. Here’s how to group and analyze our data.

  6. Health & Medicine

    Scientists Say: Tinnitus

    Ever had ringing in your ears? Tinnitus is a condition in which you hear a persistent sound that isn’t there.

  7. Health & Medicine

    Outdoor time is good for your eyes

    Being outdoors exposes children to bright light that can be good for their eyes. Spending just one extra daylight hour outdoors each week can substantially lower their chance of becoming nearsighted, a study finds.

  8. Animals

    Animals can do ‘almost math’

    Humans aren’t the only animals with a number sense. Scientists are trying to figure out where and when it evolved.

  9. Brain

    To reveal how the brain creates joy, start by tickling rats

    Rats love a good tickle. Not only do they beg for more, but the action itself activates a part of the brain that detects touch, researchers find.

  10. Health & Medicine

    Simpler way to screen for hidden hearing loss?

    Many teens today walk around with undiagnosed hearing damage. But some Boston-based researchers have come up with a low-tech approach to screening these individuals so they can get help.

  11. Health & Medicine

    Milking chocolate for its health benefits

    Researchers figure out how to give milk chocolate the same health benefits as dark chocolate. The secret ingredient is an extract from peanut skin.

  12. Health & Medicine

    Could toothpaste give heart disease the brush-off?

    Brushing with a toothpaste that dyes plaque green encourages people to remove more of it. This also lowered inflammation, which may cut someone’s risk of heart disease.