Student Author(s)

Madisyn Kovacs, Hope College

Faculty Mentor(s)

Dr. Kelly Ronald, Biology; Dr. Laura Hurley, Indiana University

Document Type


Event Date



Animals communicate with multimodal signals (e.g., a mix of auditory, visual, or olfactory information) spanning several modalities; these signals may provide receivers with more complete information to allow for more accurate behavioral decisions. Past research suggests that serotonin plays a role in encoding multimodal social information (e.g., social partner presence) during communication events. Nevertheless, to our knowledge, no experiments have explicitly tested this hypothesis. 5-HTP, a precursor for serotonin, has been shown to increase serotonin in a region of the auditory midbrain, and is affected by social context. In our experiment, we asked the question: Does an increase in 5-HTP affect the behavior and neural activity of mice (Mus musculus) when exposed to multimodal stimuli? Mice are known to use multimodal signals (vocalizations and olfactory signals) during communication and are therefore appropriate models for this experiment.To answer this question, we presented olfactory (female urine) and auditory (e.g. female ultrasonic vocalizations, USVs) stimuli to male mice. Prior to the behavioral experiment, mice were either given 5-HTP or saline. We then quantified the behaviors that occurred when male house mice were presented with either female USVs or both female urine and USVs together. We investigated sexual activity (e.g., grooming), anxious activity (e.g., digging), general activities (e.g., rearing and jumping), and investigative behavior. After exposure, neural activation was quantified via immunohistochemistry of the auditory midbrain. We predict that mice given 5-HTP and exposed to multimodal stimuli will have a higher degree of neural activation. The findings of this study will allow us to better understand the relationship between multimodal signal processing, serotonergic activity, and behavior.


Research reported in this publication was supported in part by funding provided by the National Aeronautics and Space Administration (NASA), under award number 80NSSC20M0124, Michigan Space Grant Consortium, the Anderson Research Award, and the Hope College Department of Biology. Data collection was supported by the NIH Training Grant.

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