The effect of testosterone pulses and conditioned place preferences on social behavior in wild and laboratory Peromyscus mice

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

When an individual animal interacts with another individual, it has a physiological response. The researchers are trying to understand how physiological responses can influence current and future behavior. Other studies have shown that hormones, such as testosterone, can increase after a social interaction. An important question is whether this hormone release can influence future behavior. Because some hormones can result in a positive, rewarding response, a preference for a location can form in response to the release of a hormone such as testosterone. Thus, any male-male or male-female interaction that results in the release of testosterone may induce an individual to seek out that location repeatedly. Hormone release may therefore influence how individuals use space through the development of preferences for specific locations. This research investigates, for the first time, the natural function of the reward-like properties of testosterone related to the development of preferences for specific locations. This research may reveal a new mechanism, testosterone pulses, for responding rapidly to adapt to changing social conditions associated with specific locations. The researchers use conditioned place preference development in response to testosterone injections to provide insight into the mechanisms balancing the different social demands of a monogamous and territorial species, the biparental California mouse. The hypothesis is that testosterone pulses induce spatial distributions appropriate for the social demands of the environment and, in turn, alter context appropriate behaviors in the form of paternal and territorial behavior, pair bond maintenance, mate advertisement and mate-attendance. The testosterone-induced spatial distribution may influence behavior only through location or may further amplify and alter social interactions. Within this framework, the researchers test questions in both simple and complex environments. They examine complex aspects of testosterone-modified social interactions by assessing acoustic communication in the field and laboratory. The researchers propose to examine three aims to address the function of T pulses and resulting effects on conditioned place preferences and social behavior for focal pair-bonded males and their mates (Aim 1a), focal male interactions with pups (Aim 1b), focal male interactions with a female intruder (Aim 2), and focal male interactions with a male intruder (Aim 3). This research will create a stimulating and collaborative student-training environment with unique experiences that integrate behavioral endocrinology studies in the field and laboratory. The collaboration between a midwestern R1 and small southern research institution with fieldwork conducted at the Hastings Natural History Reserve in California, will facilitate wide dissemination of expertise across researchers and students, including STEM URM students. The project will be integrated with a successful 10-year old outreach program called "Bats and Mice in Your Backyard." Two software packages are being developed to automate the analysis of ultrasonic vocalizations and mouse behavior from thermal videos collected in the field and will be made available under an open source license