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mate choice; major histocompatibility complex; fMRI
Abstract:
In many animal species, social communication and mate choice are influenced
by cues encoded by the major histocompatibility complex (MHC). The mechanism
by which the MHC influences sexual selection is a matter of intense
debate. In mice, peptide ligands of MHC molecules activate subsets of vomeronasal
and olfactory sensory neurons and influence social memory formation;
in sticklebacks, such peptides predictably modify the outcome of mate choice.
Here, we examine whether this evolutionarily conserved mechanism of interindividual
communication extends to humans. In psychometric tests, volunteers
recognized the supplementation of their body odour by MHC peptides and
preferred ‘self’ to ‘non-self’ ligands when asked to decide whether the modified
odour smelled ‘like themselves’ or ‘like their favourite perfume’.
Functional magnetic resonance imaging indicated that ‘self’-peptides specifically
activated a region in the right middle frontal cortex. Our results suggest
that despite the absence of a vomeronasal organ, humans have the ability to
detect and evaluate MHC peptides in body odour. This may provide a basis
for the sensory evaluation of potential partners during human mate choice.