Authors: Anna K Radke Nathan A Holtz Jonathan C Gewirtz Marilyn E Carroll
Publish Date: 2012/12/20
Volume: 227, Issue: 1, Pages: 117-126
Abstract
Rats bred for high HiS and low LoS saccharin intake exhibit divergent behavioral responses to multiple drugs of abuse with HiS rats displaying greater vulnerability to drug taking Previous research indicates that this effect may be due to increased sensitivity to reward in HiS rats and to the aversive effects of acute drug administration in LoS ratsEmotional signs of opiate withdrawal were assessed with potentiation of the acoustic startle reflex and conditioned place aversion CPA in male and female HiS and LoS rats Startle was measured before and 4 h after a 10mg/kg injection of morphine on days 1 2 and 7 of opiate exposure CPA was induced with a 2day naloxoneprecipitated conditioning paradigm Somatic signs of withdrawal and weight loss were also measuredMale and female LoS rats exhibited lower startle potentiation than HiS rats on the seventh day of morphine exposure LoS male rats also failed to develop a CPA to morphine withdrawal No differences in physical withdrawal signs were observed between HiS and LoS rats but males of both lines had more physical signs of withdrawal than femalesWe thank Sofiya Hupalo and Jacob Leslie for technical assistance Gail Towers for animal husbandry Dr Mark Thomas for the use of the placeconditioning apparatus and Dr Andrew Harris for assistance measuring somatic withdrawal signs This work was funded by NIDA grants K05 DA015267 and P20 DA024196 MEC and the University of Minnesota JCG
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