Researchers have developed a fluorescent imaging method to image up to five different molecule types at a time, by measuring each signal from random, distinct locations throughout a cell. This approach could allow scientists to learn much more about the complex signaling networks that control most cell functions.
There are thousands of molecules encoded by the genome, and they’re interacting in ways that we don’t understand. Only by watching them at the same time can we understand their relationships. The researchers used the fluorescent imaging technique to identify two populations of neurons that respond to calcium signals in different ways, which may influence how they encode long-term memories.
To make molecular activity visible within a cell, scientists typically create reporters by fusing a protein that senses a target molecule to a protein that glows. This is similar to how a smoke detector will sense smoke and then flash a light. The most commonly used glowing protein is green fluorescent protein (GFP), which is based on a molecule originally found in a fluorescent jellyfish.