THIRUVANANTHAPURAM: How do we get angry? What are the causative factors? What goes on within one’s cranium when this complex emotion is triggered? These were questions that fascinated Malayali scholar at the California Institute of Technology (Caltech), Aditya Nair, whose study with an international team of researchers was recently published in the international journal Cell.
Aditya discusses his work with TNIE. Edited excerpts from an interview
Why anger as a topic for research?
Our emotions govern every minute of our lives. Anger, sadness or fear dictates our interactions. And disorders of emotion are seen in neuropsychiatric issues. All emotions possess some common features. Emotions always exist in a continuum: you can be either slightly or very angry. They are persistent: once you become angry, you remain so for an amount of time. My adviser David Anderson and I hypothesised that these common features would have a common mechanism in the brain. If this were true, it would describe one of the primary principles of brain function.So we thought to understand that the principle of the brain would allow us to conquer neuropsychiatric disorders.
Could you elaborate a bit on the research?
To find the ‘anger signal’, we observed the activity of brain cells in the hypothalamus of mice using microscopes. The data was recorded as the mice engaged in aggressive behaviour. We tracked a specific brain protein, which glowed when active.To understand activity of the hypothalamus related to aggression, we used an AI-guided approach that allowed us to search for emergent signals in the brain networks. It modelled brain activity as a dynamic system — a computer model of the brain, which we could dissect.We found a neural integrator in the hypothalamus that represents an internal state of anger or aggression. We identified the anger signal is a unique feature of what’s called the ventromedial hypothalamus.
What does this entail?
Scientists have been searching for a neural correlate of anger for decades. We have known for the past few years through studies conducted in my adviser’s lab at Caltech that if the ventromedial hypothalamus region is damaged or inactivated, animals lose their aggressive drive.This work uncovers, for the first time, a correlate in the brain of an internal motive of aggressive escalation. Networks of brain cells have tremendous computing power. This is analogous to a symphony, where a group can produce music that transcends what a single instrument can produce.We found that the hypothalamus contains an integration signal. This integrator functions like a volume knob — as the ‘volume’ increases, the animal’s sense of aggression also increases.
How will this research benefit in a real-life scenario?
Understanding how the brain represents emotion would allow us to conquer neuropsychiatric disorders. A key impediment to neuropsychiatric illness is that most treatments act on the brain like a sledgehammer, as scientists do not know which brain cells and what mechanisms to specifically target.The mechanism we describe in our paper is exciting, as it gives us a handle to target disorders. Finally, we know what exactly to target.