Social play behavior, ultrasonic vocalizations and their modulation by morphine and amphetamine in Wistar and Sprague-Dawley rats.
BACKGROUND
Social play behavior is the most characteristic social behavior in young mammals. It is highly rewarding and crucial for proper neurobehavioral development. Despite the importance of genetic factors in normal and pathological social behaviors, little information is available about strain influences on social play.


OBJECTIVE
The aim of this study was to investigate differences in social play behavior, 50-kHz ultrasonic vocalizations (USVs) and their modulation by acute morphine and amphetamine administration in two rat strains widely used in behavioral pharmacology studies, i.e., Wistar and Sprague-Dawley rats.


RESULTS
Sprague-Dawley rats showed higher levels of social play than Wistar rats. In both strains, no correlation was found between the performance of social behaviors and the emission of 50-kHz USVs. In Wistar and Sprague-Dawley rats, morphine increased and amphetamine decreased social play. The effects of morphine, however, were more pronounced in Wistar than Sprague-Dawley animals. In both strains, morphine did not affect USV emission, while amphetamine increased it during cage exploration. In Sprague-Dawley rats only, amphetamine decreased USVs during social interaction.


CONCLUSIONS
Wistar and Sprague-Dawley rats differ in their absolute levels of social play behavior and 50-kHz USVs, and quantitative differences exist in their response to pharmacological manipulations of social play. The emission of 50-kHz USVs and the behavioral parameters thought to reflect rewarding social interactions in adolescent rats are dissociable.
Department of Science, Section of Biomedical Sciences and Technologies, University "Roma Tre", Viale G. Marconi 446, 00146, Rome, Italy.
Antonia
A
Manduca
Patrizia
P
Campolongo
Maura
M
Palmery
Louk J M J
LJ
Vanderschuren
Vincenzo
V
Cuomo
Viviana
V
Trezza
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D010988:Play and Playthings; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012919:Social Behavior; D013045:Species Specificity; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000187:drug effects* / Q000502:physiology
D000697:Central Nervous System Stimulants; D009294:Narcotics; D009020:Morphine; D000661:Amphetamine