title: Socially induced serotonergic fluctuations in the male auditory midbrain correlate with female behavior during courtship.
abstract: Cues from social partners trigger the activation of socially responsive neuromodulatory systems, priming brain regions including sensory systems to process these cues appropriately. The fidelity with which neuromodulators reflect the qualities of ongoing social interactions in sensory regions is unclear. We addressed this issue by using voltammetry to monitor serotonergic fluctuations in an auditory midbrain nucleus, the inferior colliculus (IC), of male mice (Mus musculus) paired with females, and by concurrently measuring behaviors of both social partners. Serotonergic activity strongly increased in male mice as they courted females, relative to serotonergic activity in the same males during trials with no social partners. Across individual males, average changes in serotonergic activity were negatively correlated with behaviors exhibited by female partners, including broadband squeaks, which relate to rejection of males. In contrast, serotonergic activity did not correlate with male behaviors, including ultrasonic vocalizations. These findings suggest that during courtship, the level of serotonergic activity in the IC of males reflects the valence of the social interaction from the perspective of the male (i.e., whether the female rejects the male or not). As a result, our findings are consistent with the hypothesis that neuromodulatory effects on neural responses in the IC may reflect the reception, rather than the production, of vocal signals.
authors.affiliation: Department of Biology, Indiana University, Bloomington, Indiana; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana; and skeesom@indiana.edu.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Keesom
authors.affiliation: Department of Biology, Indiana University, Bloomington, Indiana; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana; and Program in Neuroscience, Indiana University, Bloomington, Indiana.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Hurley
mesh_terms: D000818:Animals; D005260:Female; D007245:Inferior Colliculi / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D059326:Serotonergic Neurons / Q000378:metabolism / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism*; D012726:Sexual Behavior, Animal; D012919:Social Behavior; D014828:Vocalization, Animal
chemical_list: D012701:Serotonin
keywords: auditory; courtship; inferior colliculus; sender-receiver matching; serotonin