TY - JOUR
T1 - Limited physical contact through a mesh barrier is sufficient for social reward-conditioned place preference in adolescent male rats
AU - Peartree, Natalie A.
AU - Hood, Lauren E.
AU - Thiel, Kenneth J.
AU - Sanabria, Federico
AU - Pentkowski, Nathan S.
AU - Chandler, Kayla N.
AU - Neisewander, Janet
N1 - Funding Information:
The authors wish to thank Emile Saad for his assistance with preliminary work on this project, Heather Koch and Jose Alba for their data collection contributions, and Matthew Adams for his assistance with software setup. The project described was supported by grants DA0011064, F32DA025413, R21DA023123 and F31DA02746 from the National Institute on Drug Abuse . This research was also supported in part by funds from the More Graduate Education at Mountain States Alliance at Arizona State University and the Howard Hughes Medical Institute through the Undergraduate Science Education Program and from the Arizona State University School of Life Sciences .
PY - 2012/2/1
Y1 - 2012/2/1
N2 - Adolescence is a period of enhanced sensitivity to social influences and vulnerability to drug abuse. Social reward in adolescent rats has been demonstrated with the conditioned place preference (CPP) model, but it is not clear whether limited contact with another rat without play is sufficient to produce reward. We investigated this issue using an apparatus containing two main compartment, each with a wire mesh barrier that allowed rats placed on either side of the barrier to have limited physical contact. Adolescent male rats were given two conditioning sessions/day for 2 or 8. days following baseline preference tests. Rats were placed into their preferred side alone for one daily 10-min session and into their initially non-preferred side (i.e., CS) for the other session during which they either had restricted or unrestricted physical access to another rat (Rat/Mesh or Rat/Phys, respectively) or to a tennis ball (Ball/Mesh or Ball/Phys, respectively) unconditioned stimulus (US). Only the Rat/Phys group exhibited CPP after 2 CS-US pairings; however, after 8 CS-US pairings, the Rat/Mesh and Ball/Phys groups also exhibited CPP. During conditioning, the rat US elicited more robust approach and contact behavior compared to the ball, regardless of physical or restricted access. The incidence of contact and/or approach increased as the number of exposures increased. The results suggest that the rank order of US reward efficacy was physical contact with a rat > limited contact with a rat > physical contact with a ball, and that rough-and-tumble play is not necessary to establish social reward-CPP. The findings have important implications for emerging drug self-administration models in which two rats self-administering drug intravenously have limited physical contact via a mesh barrier shared between their respective operant conditioning chambers.
AB - Adolescence is a period of enhanced sensitivity to social influences and vulnerability to drug abuse. Social reward in adolescent rats has been demonstrated with the conditioned place preference (CPP) model, but it is not clear whether limited contact with another rat without play is sufficient to produce reward. We investigated this issue using an apparatus containing two main compartment, each with a wire mesh barrier that allowed rats placed on either side of the barrier to have limited physical contact. Adolescent male rats were given two conditioning sessions/day for 2 or 8. days following baseline preference tests. Rats were placed into their preferred side alone for one daily 10-min session and into their initially non-preferred side (i.e., CS) for the other session during which they either had restricted or unrestricted physical access to another rat (Rat/Mesh or Rat/Phys, respectively) or to a tennis ball (Ball/Mesh or Ball/Phys, respectively) unconditioned stimulus (US). Only the Rat/Phys group exhibited CPP after 2 CS-US pairings; however, after 8 CS-US pairings, the Rat/Mesh and Ball/Phys groups also exhibited CPP. During conditioning, the rat US elicited more robust approach and contact behavior compared to the ball, regardless of physical or restricted access. The incidence of contact and/or approach increased as the number of exposures increased. The results suggest that the rank order of US reward efficacy was physical contact with a rat > limited contact with a rat > physical contact with a ball, and that rough-and-tumble play is not necessary to establish social reward-CPP. The findings have important implications for emerging drug self-administration models in which two rats self-administering drug intravenously have limited physical contact via a mesh barrier shared between their respective operant conditioning chambers.
KW - Adolescence
KW - Drug self-administration
KW - Place conditioning
KW - Rough-and-tumble play behavior
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U2 - 10.1016/j.physbeh.2011.10.001
DO - 10.1016/j.physbeh.2011.10.001
M3 - Article
C2 - 22008744
AN - SCOPUS:80155161359
SN - 0031-9384
VL - 105
SP - 749
EP - 756
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 3
ER -