Behavior Genetics

, Volume 35, Issue 1, pp 67–72

Breeding for 50-kHz Positive Affective Vocalization in Rats

Authors

  • Jeffrey Burgdorf
    • J.P. Scott Center for Neuroscience, Mind and Behavior Department of PsychologyBowling Green State University
    • J.P. Scott Center for Neuroscience, Mind and Behavior Department of PsychologyBowling Green State University
    • Falk Center for Molecular Therapeutics, McCormick School of EngineeringDepartment of Biomedical Engineering Northwestern University
  • Stefan M. Brudzynski
    • Centre for Neuroscience, Department of PsychologyBrock University
  • Roger Kroes
    • Falk Center for Molecular Therapeutics, McCormick School of EngineeringDepartment of Biomedical Engineering Northwestern University
  • Joseph R. Moskal
    • Falk Center for Molecular Therapeutics, McCormick School of EngineeringDepartment of Biomedical Engineering Northwestern University
Article

DOI: 10.1007/s10519-004-0856-5

Cite this article as:
Burgdorf, J., Panksepp, J., Brudzynski, S.M. et al. Behav Genet (2005) 35: 67. doi:10.1007/s10519-004-0856-5

Abstract

Adolescent and adult rats exhibit at least two distinct ultrasonic vocalizations that reflect distinct emotional states. Rats exhibit 22-kHz calls during social defeat, drug withdrawal, as well as in anticipation of aversive events. In contrast, 50-kHz calls are exhibited in high rates during play behavior, mating, as well as in anticipation of rewarding events. The neurochemistry of 22-kHz and 50-kHz calls closely matches that of negative and positive emotional systems in humans, respectively. The aim of this study was to replicate and further evaluate selective breeding for 50-kHz vocalization, in preparation for the analysis of the genetic underpinnings of the 50-kHz ultrasonic vocalization (USV). Isolate housed adolescent rats (23–26 days old) received experimenter administered tactile stimulation (dubbed “tickling”), which mimicked the rat rough-and-tumble play behavior. This stimulation has previously been shown to elicit high levels of 50-kHz USVs and to be highly rewarding in isolate-housed animals. Each tickling session consisted of 4 cycles of 15 seconds stimulation followed by 15 seconds no stimulation for a total of 2 min, and was repeated once per day across 4 successive days. Rats were then selected for either High or Low levels of sonographically verified 50-kHz USVs in response to the stimulation, and a randomly selected line served as a control (Random group). Animals emitted both 22-kHz and 50-kHz types of calls. After 5 generations, animals in the High Line exhibited significantly more 50-kHz and fewer 22-kHz USVs than animals in the Low Line. Animals selected for low levels of 50-kHz calls showed marginally more 22-kHz USVs then randomly selected animals but did not differ in the rate of 50-kHz calls. These results extend our previous findings that laboratory rats could be bred for differential rates of sonographically verified 50-kHz USVs.

Keywords

Emotionmotivationratsrewardselective breedingultrasonic vocalization

Copyright information

© Springer Science+Business Media, Inc. 2005