Figure 1.
Effects of HSV vector-mediated alterations in gene expression in the NAc shell on ICSS. a, Expression of β-galactosidase, induced by bilateral microinjections of HSV-LacZ into the NAc (ac) shell, 3 d after gene transfer in a brain section costained for TH (magnification, 40×). b–d, Elevated GluR1 (b) expression in this region caused rightward shifts in rate-frequency functions, whereas elevated GluR2 (c) expression caused leftward shifts and β-galactosidase (d) had no effect. Data are from representative rats tested 3 d after gene transfer; for clarity, only the third of four daily rate-frequency determinations is shown. e, Effect of gene transfer on mean (±SEM) ICSS thresholds in 1 h test sessions across the 8 d test period. f, Elevated GluR2 decreased ICSS thresholds, whereas elevated GluR1 increased thresholds relative to rats treated with HSV-LacZ (F(14,182) = 2.15; p < 0.02), although none of the treatments affected response rates. Data are expressed as percentage of pre-gene transfer baselines. *p < 0.05, **p < 0.01 (Fisher's tests).