What’s the main idea of the passage?

Like people who share news via Twitter, Facebook and Linkedln, cells, too, make use of multiple modes of information exchange. Some send out hormones, which travel far and wide via the bloodstream; others emit neurotransmitters, which carry signals between one neuron and another. But virtually all cells network with their neighbors via extensive collections of channels that directly connect the inside of one cell with the inside of the next.

Researchers studied the differences that occur when people focus on their burdens versus focusing on what they are grateful for. Simply acknowledging a few things you feel grateful for each day is a powerful way to create change. In fact, gratitude not only impacts your psychological health, it can also affect your physical health. A 2003 study published in the Journal of Personality and Social Psychology found that people who feel gratitude don’t get sick as often as others.