Figure 3
Inhibition of protein synthesis prevents the long-lasting, but not the acute, effects of recombinant glial cell line-derived neurotrophic factor (rGDNF) on alcohol consumption. Rats consumed a solution of 20% alcohol for 7 weeks. Cycloheximide (CHX; 2 mg kg−1, i.p.) was administered 1 h before and 3 h after the beginning of the alcohol-drinking session. rGDNF (10 μg per side) was infused into the ventral tegmental area (VTA) 10 min before the beginning of the drinking session. (a) Timeline of treatments and consumption measurements schedule. (a and b) Data are expressed as mean±s.e.m. of alcohol intake in g kg−1 (*P<0.01 vs vehicle–vehicle; n=12). (b) Alcohol intake during the first 30 min of the drinking session (two-way repeated measurements analysis of variance (ANOVA): a main effect of rGDNF infusion (F (1,13)=34.79, P<0.0001), no effect of CHX pretreatment (F (1,13)=1.28, P=0.28), and no interaction (F (1,13)=0.07, P=0.79)). (c) Alcohol intake during the 4–24-h time period after the beginning of the drinking session (two-way repeated measurements ANOVA: no effect of rGDNF infusion (F (1,13)=2.19, P=0.16), a significant main effect of CHX pretreatment (F (1,13)=10.46, P<0.007), and a significant interaction (F (1,13)=13.16, P<0.005). Post-hoc comparisons: a significant difference between rGDNF- and vehicle-infused rats in the vehicle control rats (P<0.01), but not in rats that were pretreated with CHX (P=0.086)).
