Technological developments that allow researchers to image the activity of the majority of neurons in the head area of a living Caenorhabditis elegans are reported in a paper published online this week in Nature Methods. The technique will open new possibilities for studying the function of the organism’s nervous system and for pairing brain function to brain anatomy.

Recent efforts in neuroscience have aimed to obtain detailed brain activity maps of large groups of neurons. It is believed that observing the activity of cells across the whole brain will reveal important information about how the brain stores information and controls actions. The simple worm model organism, C. elegans, has 302 neurons in its body whose anatomical locations and connectivity have been mapped. However, neuronal activity had only been measured in a few individual neurons at a time.

Alipasha Vaziri, Manuel Zimmer and colleagues developed a number of imaging technology advances and a neuronal activity reporter that enable imaging of the activity of about one-third of the neurons in the worm (which includes about 70% of the neurons in the worm’s head).