Role of stress in acquisition of alcohol-conditioned place preference in adolescent and adult mice.
BACKGROUND
Both clinical evidence and findings from animal models demonstrate that there are differences between adolescents and adults in alcohol dependence. As stress plays a critical role in processes of alcohol addiction, we tested whether stress is involved in alcohol vulnerability differently during adolescence and adulthood in mice.


METHODS
To determine whether age differences exist in the acquisition of alcohol-conditioned place preference (CPP) in mice, adolescent and adult mice were trained for CPP with different doses of alcohol (0, 0.5, 1, and 2 g/kg, i.p.). To explore the effects of stress (footshock) on acquisition of alcohol CPP in mice of different ages, adolescent and adult mice underwent acute (1 day) or chronic (1 week) stress before CPP training. Acquisition of CPP was examined after the CPP training.


RESULTS
Under nonstress conditions, adult mice acquired alcohol CPP when trained with 2 g/kg alcohol, while adolescent mice did not acquire alcohol CPP. After chronic but not acute stress exposure, adolescent mice acquired significant CPP trained with 2 g/kg alcohol that did not produce CPP under nonstress conditions. However, stress did not have significant effect on acquisition of CPP in adult mice trained CPP with 1 g/kg alcohol.


CONCLUSIONS
These results indicate that there is an age difference in acquiring alcohol CPP and adolescent mice are more sensitive than adults to stress.
Song
Mei
M
Institute of Mental Health, Hebei Medical University, Shijiazhuang, China.
Wang
Xue-Yi
XY
Zhao
Mei
M
Wang
Xiao-Yi
XY
Zhai
Hai-Feng
HF
Lu
Lin
L
D000367:Age Factors; D000428:Alcohol Drinking / Q000523:psychology*; D000437:Alcoholism / Q000523:psychology; D000818:Animals; D001245:Association Learning; D002755:Choice Behavior; D003214:Conditioning, Classical; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D000431:Ethanol / Q000008:administration & dosage; D005239:Fear; D005260:Female; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D012931:Social Environment; D013315:Stress, Psychological / Q000150:complications / Q000523:psychology*
D000431:Ethanol