By washing through the brain, neuromodulators “allow you to govern the excitability of a large region of the brain more or less in the same way or at the same time,” said Eve Marder, a neuroscientist at Brandeis University widely recognized for her pioneering studies on neuromodulators in the late 1980s. “You’re basically creating either a local brain wash or more extended brain wash that is changing the state of a lot of networks simultaneously.”
The powerful effects of neuromodulators mean that abnormal levels of these chemicals can lead to numerous human diseases and mood disorders. But within their optimal levels, neuromodulators are like secret puppeteers holding the strings of the brain, endlessly shaping circuits and shifting activity patterns into whatever may be most adaptive for the organism, moment by moment.
“The neuromodulatory system [is] the most brilliant…