Meeting Abstract

P2.97  Tuesday, Jan. 5  Social interactions influence serotonin in the auditory system. HALL, IC*; SELL, GL; HURLEY, LM; Indiana University Bloomington; Indiana University Bloomington; Indiana University Bloomington ichall@indiana.edu

One mechanism by which serotonin may influence social behavior is through the modulation of sensory processing. To investigate this possibility, we used voltammetry to measure levels of serotonin in the auditory midbrain (inferior colliculus, IC) of male mice during a resident-intruder interaction. A significant increase in serotonin was observed in the IC of resident mice during the social interaction. The serotonergic response was not correlated with the age or mass of the intruders relative to those of the residents but was correlated with the duration of anogenital investigation during the interaction. These data suggest that the behaviors demonstrated during a social interaction can influence levels of IC serotonin. To investigate how repeated exposures to a social stimulus influence the behavioral and serotonergic response, the same resident mice were tested again with different intruders. During a second interaction, in addition to the behavioral correlation, the magnitude of the residents’ serotonergic response was correlated with the magnitude of the serotonergic responses observed during the first interaction. These data indicate that the change in IC serotonin is not solely influenced by the interaction between mice but that the magnitude of the serotonergic response also varies with the individual, suggesting that each mouse has a unique neurochemical response profile that contributes to its behavioral phenotype.