A team of researchers from Duke University has just identified a group of specialized brain cells that are needed for mice to serenade a potential suitor. While neuroscientists had previously shown that a brain region called the midbrain periaqueductal gray (PAG) was important for vocal production, narrowing in on the specific neurons involved had previously proven difficult, given that this a region of the brain is also responsible for many other behaviors.
In the recent study led by postdoctoral fellow Katherine Tschida, the researchers took advantage of a recently-developed genetic approach to label or “tag” the neurons activated when male mice were belting out their love songs. This tag then helped them see how those neurons were connected to other regions in the brain thought to be involved in coordinating breathing and movements of the voice.
Then, to establish that this group of neurons was linked to mouse love songs, the researchers inactivated them and found that this rendered the male mice unable to sing. Conversely, by purposely activating these neurons, Tschida and her colleagues could get the male mice to sing even when female mice were not around. The scientists were also able to show that these love songs seemed to be a good strategy for holding a female mouse’s interest: on average, female mice spent more time with male mice who sang more.
The accompanying videos (credit: Duke University) of these singing mice are adorable. But, cuteness aside, advances in genetic techniques to target groups of neurons for specific labeling, inactivation, and activation are allowing neuroscientists to pinpoint the networks of cells involved in complex behaviors, mapping out the circuits of electric activity in the brain.