Glutamatergic synapses from the insular cortex to the basolateral amygdala encode observational pain
Ming-Ming Zhang1, An-Qi Geng2, Kun Chen1
1Department of Anatomy and K.K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an 710032, China.
Neuron
|April 20, 2022
Summary
Researchers discovered a new neural pathway in mice that explains how observing pain in others leads to experiencing pain. This pathway involves the insular cortex and basolateral amygdala, crucial for social pain perception.
Area of Science:
- Neuroscience
- Social Psychology
- Pain Research
Background:
- Empathic pain, or experiencing pain due to observing others, is a recognized phenomenon across sociological, psychological, and neuroscience disciplines.
- Despite significant interest, the precise neural mechanisms underlying empathic pain remain largely unknown.
- Understanding these mechanisms is crucial for addressing conditions involving social pain perception.
Purpose of the Study:
- To elucidate the neural pathways and molecular mechanisms responsible for observational pain in a mouse model.
- To identify specific synaptic components involved in the social transfer of pain.
Main Methods:
- Establishment of a long-term observational pain model in mice.
- Investigation of the insular cortex (IC) to basolateral amygdala (BLA) glutamatergic projection.
- Selective activation and inhibition of the IC-BLA pathway.
- Screening of synaptic molecules, including synaptotagmin-2 and RIM3.
Main Results:
- The glutamatergic projection from the IC to the BLA was identified as critical for observational pain formation.
- Activation of the IC-BLA pathway enhanced observational pain, while inhibition weakened it.
- Upregulation of synaptotagmin-2 and RIM3 was identified as a key molecular signal driving increased glutamate transmission in this pathway.
Conclusions:
- A novel neural pathway, the IC-BLA projection, is essential for regulating observational pain in mice.
- Specific synaptic molecules, synaptotagmin-2 and RIM3, play a key role in modulating pain empathy.
- This study reveals the molecular and synaptic underpinnings of a previously unknown mechanism for social pain perception.
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