Adolescent

Individual Pair

*

*

#

10

20

30

40

50

60

70

80

0

Housing Condition

Pre

fere

nce

Sco

re

Adult

Individual Pair

Housing Condition

Social Interaction vs. AMPH CPP

Preference forsocial interaction

Preference forAMPH

Adolescent

Individual Pair

*

0

10

20

30

40

50

60

70

80

Housing ConditionP

refe

ren

ce S

core

Adult

Individual Pair

Housing Condition

Social Interaction CPP

Preference forsocial interaction

Aversion tosocial interaction

Adolescent

Individual Pair

**

0

10

20

30

40

50

60

70

80

Housing Condition

Pre

fere

nce

Sco

re

Adult

Individual Pair

*

Housing Condition

AMPH CPP

Preference forAMPH

Aversion toAMPH

Concurrent Choice between Cues for Social Interaction and Amphetamine in Adolescent and Adult Rats: Effects of Housing Condition

Justin R. Yatesa,b, Joshua S. Beckmanna,b, Andrew C. Meyerc, & Michael T. Bardoa,b

aDepartment of Psychology, University of KentuckybCenter for Drug Abuse Research Translation (CDART)

cDepartment of Psychiatry, University of Vermont Introduction • Human adolescents are more likely to experiment with

drugs of abuse in the presence or their peers [1] • Dyadic social interactions have also been described as an

essential therapeutic factor in abstaining from drugs of abuse [2]

• Previous preclinical research has shown that social interaction reverses psychostimulant reward in individually-housed adult rats [3].

• The present study was designed to determine if social interaction can attenuate amphetamine (AMPH) reward in individually- or pair-housed adolescent and adult rats

Methods Animals: Male Sprague Dawley rats arrived at postnatal day

(PND) 21 (n=54) or PND 60 (n=44) and were housed individually or in pairs.

Procedure: Beginning on PND 28 (adolescent) or PND 67 (adult), rats went through a 10-day conditioned place preference (CPP) paradigm. Session 1 (Pre-test): Rats allowed to explore all three

compartments of the CPP chamber for 15 min Sessions 2-9 (Conditioning): Rats were treated on alternating days as follows: (1) AMPH (1 mg/kg, s.c.) in

one compartment (counterbalanced) + saline in the other; (2) saline with a social partner in one compartment + saline alone in the other; or (3) saline with a social partner in one compartment + AMPH alone in the other. Each conditioning session lasted 30 min. Session 10 (Posttest): Rats allowed to explore all three

compartments for 15 minAnalyses: Preference score calculated following posttest:

Figure 1.

References

Acknowledgements Funding provided by NIH grants P50 DA05312 , R01 DA

12964 and T32 DA016176.

Figure 2.

Discussion• Overall results suggest that individually-housed adolescent rats were

most sensitive to the rewarding effect of social interaction, and this hypersensitivity to social reward effectively competed with AMPH reward

• Future studies will examine other parametric manipulations, including:1) AMPH dose2) Duration of conditioning trial

3) Sex differences

Figure 3.

Experiments 1 & 2Time spent (in sec) in social interaction/AMPH chamberTime spent (in sec) in social interaction/AMPH chamber AND saline chamber

X100

Experiment 3Time spent (in sec) in social interaction chamberTime spent (in sec) in social interaction chamber AND AMPH chamber

X100[1] Bahr SJ, Hoffmann JP, Yang X (2005) Parental and peer

influences on the risk of adolescent drug use. The Journal of Primary Prevention, 26, 529-551.

[2] Grawe K (1997) Research-informed psychotherapy. Psychotherapy Research, 7, 1-19

[3] Fritz M, El Rawas R, Salti A, Klement S, Bardo MT, Kemmler G, Dechant G, et al. (2011) Reversal of cocaine-conditioned place preference and mesocorticolimbic Zif268 expression by social interaction in rats. Addiction Biology, 16, 273-284.

Adolescent AMPH

Adolescent Saline

Adult AMPH

Adult Saline

Conditioning Trial 1 26.8 (± 2.3)# 20.7 (± 1.4) 20.6 (± 1.0) 20.7 (± 2.2)

Conditioning Trial 2 27.7 (± 2.1)* 20.2 (± 1.7) 24.1 (± 1.0)* 19.1 (± 2.0)

Conditioning Trial 3 28.2 (± 2.2)* 19.8 (± 1.6) 28.4 (± 1.4)* 18.3 (± 1.3)

Conditioning Trial 4 30.5 (± 2.9)* 18.1 (± 1.6) 29.8 (± 1.4)* 19.76 (± 1.6)

Table 1. Locomotor activity (mean photobeam breaks ± SEM) during conditioning trials for Experiment 2 (AMPH-induced CPP)

*p < .05, relative to saline#p < .05, relative to adults treated with AMPHNote: Data from individually- and pair-housed animals have been combined into one group

*p < .05, relative to a preference score of 50#p < .05, individually-housed adolescents relative to pair-housed adolescents