Aug. 30: Neuronal Diversity Makes a Difference, Says Carnegie Mellon Study - Carnegie Mellon University

Aug. 30: Neuronal Diversity Makes a Difference, Says Carnegie Mellon Study - Carnegie Mellon University: By placing an electrical probe into individual excitatory neurons called mitral cells and exposing them to a complex computer-controlled noise stimulus, the researchers were able to determine how each cell responded. They found that out of the dozens of neurons they tested, no two had the exact same response. While the researchers believed that these results were striking on their own, it led them to wonder whether or not the neurons were giving a messy version of a single response, or if they were each providing different pieces of information about the stimulus.

To test their hypothesis, the CMU researchers used a tool called spike-triggered averaging that allowed them to determine what feature of the stimulus causes each neuron to respond. They found that some responded to rapid changes in the stimulus and others to slower changes; still other neurons responded when the input signal changed in a regular or rhythmic way. The researchers then computed the information contained in the outputs of highly diverse sets of neurons and compared it to that of groups of more similar neurons. They found that the heterogeneous groups of neurons transmitted two times as much information about the stimulus than the homogeneous group.