A1 Refereed original research article in a scientific journal
Mu-opioid receptor system modulates responses to vocal bonding and distress signals in humans
Authors: Sun Lihua, Lukkarinen Lasse, Putkinen Vesa, Karlsson Henry K, Hirvonen Jussi, Tiihonen Jari, Lauerma Hannu, Scott Sophie, Nummenmaa Lauri
Publisher: ROYAL SOC
Publication year: 2022
Journal: Philosophical Transactions B: Biological Sciences
Journal name in source: PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
Journal acronym: PHILOS T R SOC B
Article number: 20210181
Volume: 377
Issue: 1863
Number of pages: 8
ISSN: 0962-8436
eISSN: 1471-2970
DOI: https://doi.org/10.1098/rstb.2021.0181
Web address : https://doi.org/10.1098/rstb.2021.0181
Preprint address: https://www.biorxiv.org/content/10.1101/2021.09.16.460660v1
Laughter is a contagious prosocial signal that conveys bonding motivation; adult crying conversely communicates desire for social proximity by signalling distress. Endogenous mu-opioid receptors (MORs) modulate sociability in humans and non-human primates. In this combined PET-fMRI study (n = 17), we tested whether central MOR tone is associated with regional brain responses to social signals of laughter and crying. MOR availability was measured with positron emission tomography (PET) using the high-affinity agonist radioligand [C-11]carfentanil. Haemodynamic responses to social laughter and crying vocalizations were measured using functional magnetic resonance imaging (fMRI). Social laughter evoked activation in the auditory cortex, insula, cingulate cortex, amygdala, primary and secondary somatosensory cortex, and primary and secondary motor cortex; crying sounds led to more restricted activation in the auditory cortex and nearby areas. MOR availability was negatively correlated with the haemodynamic responses to social laughter in the primary and secondary somatosensory cortex, primary and secondary motor cortex, posterior insula, posterior cingulate cortex, precuneus, cuneus, temporal gyri and lingual gyrus. For crying-evoked activations, MOR availability was negatively correlated with medial and lateral prefrontal haemodynamic responses. Altogether our findings highlight the role of the MOR system in modulating acute brain responses to both positive and negative social signals.This article is part of the theme issue 'Cracking the laugh code: laughter through the lens of biology, psychology and neuroscience'.
