Behavior Genetics

, Volume 35, Issue 1, pp 67–72

Breeding for 50-kHz Positive Affective Vocalization in Rats

  • Jeffrey Burgdorf
  • Jaak Panksepp
  • Stefan M. Brudzynski
  • Roger Kroes
  • Joseph R. Moskal
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

Authors and Affiliations

  • Jeffrey Burgdorf
    • 1
  • Jaak Panksepp
    • 1
    • 2
  • Stefan M. Brudzynski
    • 3
  • Roger Kroes
    • 2
  • Joseph R. Moskal
    • 2
  1. 1.J.P. Scott Center for Neuroscience, Mind and Behavior Department of PsychologyBowling Green State UniversityBowling GreenUSA
  2. 2.Falk Center for Molecular Therapeutics, McCormick School of EngineeringDepartment of Biomedical Engineering Northwestern UniversityEvanstonUSA
  3. 3.Centre for Neuroscience, Department of PsychologyBrock UniversitySt. CatharinesCanada