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New Brain Signature of Empathy Discovered

New Brain Signature of Empathy Discovered

Quick Hits
Daily brief research updates from the cognitive sciences

There have been numerous brain areas associated with empathy and feeling for others – some of which I have written about in other places. However, researchers at the Institute for Basic Science in South Korea have now discovered a new signature and underlying neural mechanisms to empathy.

Empathy is a critical aspect of human sociality giving us the capacity to sense, feel, and share the emotions of others. But the biological mechanisms are also shared with other animal – including rodents. This study focused on “observational fear”, commonly used in scientific research as a basic form of emotional contagion and affective empathy.

In this experimental protocol, one mouse is given a small electrical shock, poor mouse. Another can see this through a transparent screen. The observer mouse will also immediately exhibit a fear response and freeze. What the researchers were able to do is to see that this empathetic fear response is different to the first-hand experienced fear response and is coordinated by brain waves that are synchronised between different brain regions. Specifically, two areas, one called the Anterior Cingulate Cortex (ACC) which helps with attention, and a part of the Amygdala (BLA) which is involved in fear and threat detection.

In the observer mice there was a pattern of increased slow waves, 5-7Hz (theta brain waves), between these two regions. In the mice that experienced the shock, and therefore a fear response, slow waves were only seen in the Amygdala. This suggests two different patterns. The researchers then tested the causality to see if this does indeed trigger this behaviour. What they found is that if they inhibited the rhythms in the ACC-BLA circuit then it significantly impacted the observational fear freezing.

Furthermore, this seems to be controlled by another regions in the brain known as the hippocampus which is generally responsible for memory and navigation. Hippocampus theta rhythms seem to coordinate these regions – similarly by disrupting the hippocampal theta rhythms observational fear freezing was inhibited or increased.

So, this gives us some clear evidence that empathy is also driven by coordination between different brain regions and coordinated by the hippocampus. Whether this is for all types of emotions is another question but intriguing it is.

For us human beings there is no obvious way to synchronize theta brain waves – so no help on the horizon for those lacking empathy – or to turn it down either!

Andy Habermacher

Andy Habermacher

Andy is author of leading brains Review, Neuroleadership, and multiple other books. He has been intensively involved in writing and research into neuroleadership and is considered one of Europe’s leading experts. He is also a well-known public speaker, speaking on the brain and human behaviour.

Andy is also a masters athlete (middle distance running) and competes regularly at international competitions (and holds a few national records in his age category).

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References

Seong-Wook Kim, Minsoo Kim, Jinhee Baek, Charles-Francois Latchoumane, Gireesh Gangadharan, Yongwoo Yoon, Duk-Soo Kim, Jin Hyung Lee, Hee-Sup Shin. 
Hemispherically lateralized rhythmic oscillations in the cingulate-amygdala circuit drive affective empathy in mice
Neuron, 2022
DOI: 10.1016/j.neuron.2022.11.001

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How Your Silent Synapses Boost Brain Power

How Your Silent Synapses Boost Brain Power

Quick Hits
Daily brief research updates from the cognitive sciences

brain motivation

There are different types of dark matter in the brain. Matter that is often little researched or unknown to different population groups. I have written previously about glial cells and their contribution to just about everything, something neuroscientists know a lot about, to electrical neurons, that have been vastly under researched.

But now some researchers have made some discoveries in another area, and that is that of silent synapses. Synapses are the connections between your brain cells. The current understanding is that as you learn, develop new skills, synapses connect, and strengthen and build the networks in your brain – this is how your brain is continually growing and changing. However, these would always be part of a network. Silent, inactive synapses have been seen in the brains of developing mice so it was thought they played a key role in the developing brain but not in adults.

However, in an unexpected discovery MIT researchers have found silent synapses at levels 10 times higher than expected. The researchers were not actually looking for silent synapses but trying to measure neurotransmitter receptors on the branches of neurons. Some of these branches and connections, known as filopodia, are extremely fine and small and are difficult, or impossible, to see with standard imaging techniques.

On discovering these in such high quantities they then proceeded to investigate whether they were indeed silent synapses by attempting to stimulate these with a combination of a neurotransmitter and an electrical stimulus. They found that indeed these were silent but could grow into active synapses much quicker than by altering mature synapses.

That’s good news and this explains how we can learn things quicker – having silent synapses allows rapid learning and being able to build new memories without building whole new synapses.

Whether this is different between different people is another question – but I am hoping I have a bunch of silent synapses waiting to spring into action when I engage with new material – such as writing this article – go silent synapses, go!

Andy Habermacher

Andy Habermacher

Andy is author of leading brains Review, Neuroleadership, and multiple other books. He has been intensively involved in writing and research into neuroleadership and is considered one of Europe’s leading experts. He is also a well-known public speaker, speaking on the brain and human behaviour.

Andy is also a masters athlete (middle distance running) and competes regularly at international competitions (and holds a few national records in his age category).

twitter / LinkedIn

References

Vardalaki, D., Chung, K. & Harnett, M.T. 
Filopodia are a structural substrate for silent synapses in adult neocortex
Nature, 2022
DOI: 10.1038/s41586-022-05483-6

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