Effects of NTX in males. (A) Upper panel. Cumulative EtOH intake after NTX or VEH administration in EtOHPD animals and EtOHND animals at A-Abst, L-Abst, and P-Abst. Lower panel. Responses at the inactive lever. (B) Blood alcohol levels (BAL) were measured immediately after self-administration following NTX or vehicle (VEH) administration in EtOHPD and EtOHND animals at A-Abst, L-Abst, and P-Abst. (C) Somatic withdrawal signs (WDS) were recorded prior to EtOH self-administration before NTX or VEH administration in EtOHPD and EtOHND animals at A-Abst, L-Abst, and P-Abst. The Y-axis for WDS is expressed as log10. *p < 0.05, vs. respective VEH (Tukey post hoc test); +p < 0.05, ++p < 0.001, vs. EtOHND (Tukey post hoc test). n = 5/6 animals/group.