TY - JOUR TI - Investigation of the behavioral processes and neurobiological substrates involved in the motivation for voluntary wheel running in the rat DO - https://doi.org/doi:10.7282/T3RR1X02 PY - 2013 AB - Rats engage with voluntary running wheels spontaneously and come to run tremendous, stable distances over the first 3 weeks of wheel exposure, with males and females showing significant differences in this behavior. Though voluntary running has been utilized extensively to study its effects on the body and brain, less has been done to examine the behavior itself, and specifically lacking are studies that focus on the motivation for the behavior and any gender differences within. Here, I investigate, in a comprehensive, quantitatively comparable manner, details of voluntary wheel running and variables that affect it in both male and female Sprague Dawley rats. Using both unconditioned and conditioned techniques, I explore my primary hypothesis that voluntary wheel running is a motivated behavior with positive incentive salience, with a focus on the motivation for this behavior during both the acquisition and habitual phases of running. I then utilize these behavioral techniques to explore the involvement of discrete brain regions in the motivation for voluntary wheel running. Results from this work support the hypothesis that voluntary wheel running is a motivated behavior with positive incentive salience. The data reveal that females acquire the behavior more quickly and during habitual phases of running, run significantly farther distances at faster rates. Additionally, I show using high-performance liquid chromatography that participating in voluntary wheel running throughout life alters neurotransmitter content in brain areas including the caudate putamen, ventral tegmental area, medial prefrontal cortex (mPFC) and medial preoptic area, and that engaging in this motivated behavior throughout life alters both the neurochemical and behavioral responsiveness to an acute dose of cocaine. Though males and females show an equally robust conditioned place preference for the total experience of running during the acquisition phase, the reinstatement of running after a period of forced wheel abstinence is greater for females than males, with males showing a stronger preference for the aftereffects of wheel running. Finally, I reveal for the first time that the prelimbic mPFC and nucleus accumbens core may be necessary for the motivation for voluntary wheel running. KW - Neuroscience KW - Rats as laboratory animals KW - Rats--Behavior KW - Rats--Locomotion KW - Rats--Psychology LA - eng ER -