Neurons must generate the right amount of activity at the right time for our brains to produce healthy behaviors. To do this throughout life, neurons are thought to have their own “activity monitors,” which allows them to sense how active they are, and then dial their output up or down to maintain homeostasis. Dogma in the field suggests that neurons of the same type (e.g., that produce the same behavior) use the same core set of cellular mechanisms to track and regulate their activity.

In a new paper published in PLOS Biology, Dr. Joe Santin’s lab found that neurons that generate breathing in frogs sense and regulate their activity by co-expressing two different activity sensors in differing amounts across individual neurons of the population. The expression of these sensors, which respond to sodium and a voltage, appeared to be “scaled” such that when the sodium sensor was high, the voltage sensor was low and vice versa along a continuum. These results show that each component of a biological system uses different regulatory rules to maintain output of the whole system: no two neurons are regulated by same feedback mechanisms, yet they assemble to generate proper behavior. Negative feedback is a fundamental principle in biology and engineering, and these data put forth a new way to think about how biological systems may achieve robustness by scaling the function of multiple feedback systems among their components.

We are excited to see this out!! Great work by former MS student @PellizzariSarah about how groups of neurons control their activity levels using different combinations of regulatory mechanisms from cell to cell. https://t.co/u597FJP5Wy

— Joe Santin (@santin_joe) January 24, 2023