Effect of prenatal stress on alcohol preference and sensitivity to chronic alcohol exposure in male rats
Psychopharmacology. 2010-01-27; 214(1): 197-208
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RATIONALE: In rats, prenatal restraint stress (PRS) induces persistent behavioral
and neurobiological alterations leading to a greater consumption of
psychostimulants during adulthood. However, little is known about alcohol
vulnerability in this animal model.
OBJECTIVES: We examined in adolescent and adult male Sprague Dawley rats the
long-lasting impact of PRS exposure on alcohol consumption.
METHODS: PRS rats were subjected to a prenatal stress (three daily 45-min
sessions of restraint stress to the mothers during the last 10 days of
pregnancy). Alcohol preference was assessed in a two-bottle choice paradigm
(alcohol 2.5%, 5%, or 10% versus water), in both naïve adolescent rats and adult
rats previously exposed to a chronic alcohol treatment. Behavioral indices
associated with incentive motivation for alcohol were investigated. Finally,
plasma levels of transaminases (marker of hepatic damages) and ΔFosB levels in
the nucleus accumbens (a potential molecular switch for addiction) were evaluated
following the chronic alcohol exposure.
RESULTS: Alcohol preference was not affected by PRS. Contrary to our
expectations, stressed and unstressed rats did not display signs of compulsive
alcohol consumption. The consequences of the alcohol exposure on locomotor
reactivity and on transaminase levels were more prominent in PRS group.
Similarly, PRS potentiated alcohol-induced ΔFosB levels in the nucleus accumbens.
CONCLUSION: Our data suggest that negative events occurring in utero do not
modulate alcohol preference in male rats but potentiate chronic alcohol-induced
molecular neuroadaptation in the brain reward circuitry. Further studies are
needed to determine whether the exacerbated ΔFosB upregulation in PRS rats could
be extended to other reinforcing stimuli.