Chunk #24 — RESULTS — Reductions in responding for ethanol after GABAAR α4 subunit knockdown are present when testing occurs at the time of maximal knockdown and require ethanol reinforcement
As expected, rats with GABAAR α4 subunit reduction showed decreased total active lever responses on day 18 after viral infusion when those responses were reinforced with ethanol (P < 0.001; Fig. 3a). The ethanol intake of the rats with the reduced expression of the GABAAR α4 subunit (0.32 + 0.04 g/kg) was also significantly lower across the entire session than the ethanol intake of control rats (0.66 + 0.08 g/kg; P < 0.001, t-test). Within-session examination of responding indicated that the two groups did not differ during the baseline session [Fig. 3b; significant main effect of time (F(5,70) = 34.11, P < 0.001), but not virus treatment (F(1,70) = 3.6, P = 0.98), nor treatment by time interaction (F(5,70) = 0.12, P = 0.98)]. However, as seen in Fig. 3c, on day 18, rats with GABAAR α4 subunit knockdown in the NAc shell made significantly fewer active lever responses as compared to control rats [main effect of time (F(5,70) = 34.11, P < 0.001), virus treatment (F(1,70) = 18.11, P < 0.001), treatment by time interaction (F(5,70) = 2.67, P
