Effects of local perfusion of the adenosine transport inhibitor NBTI (1 μM). (A) Microdialysis perfusion of NBTI increases adenosine concentrations in both the basal forebrain (paired t test, t(5) = 4.79 and P < 0.01) and the thalamus (paired t test, t(4) = 3.92 and P < 0.05) by about twofold (the means of the last three samples before and the means of the first three samples after onset of NBTI perfusion are compared). (B) NBTI administration causes sleep-wakefulness changes in the basal forebrain (left panel) but not in the VA / VL thalamus (right panel). In the basal forebrain, the paired t test gave values of t(5) = 3.47 and P < 0.05 for waking, t(5) = 3.78 and P < 0.05 for SWS, and t(5) = 2.76 and P < 0.05 for REM sleep. Changes in the thalamus are P = NS for all states. The ordinate shows the minutes spent in each state during the 3-hour recording period. (C) NBTI causes changes in the power spectrum when administered in the basal forebrain but not in the VA / VL thalamus. The relative power is increased in the delta band (0.3 to 4 Hz) and decreased in the gamma band (35 to 55 Hz) with NBTI infusion in the basal forebrain (P < 0.04; nonparametric Wilcoxon tests were used because of nonnormality of data) but is unchanged with NBTI infusion in the thalamus. (D) Comparison of the effects of prolonged wakefulness and NBTI perfusion in the basal forebrain on the percent of time spent in each behavioral state. During both the NBTI treatment and the recovery sleep conditions, SWS was increased as compared with control sleep [40 and 50%, respectively; n = 5; repeated measures of ANOVA between treatments gave values of F(2, 4) = 5.92 and P < 0.05], and this increase in SWS did not differ between the NBTI and recovery sleep conditions (post hoc Neuman Keul). Wakefulness was decreased in both experimental conditions as compared to control sleep [45 and 50%, respectively; repeated measures of ANOVA between treatments gave values of F(2, 4) = 9.41 and P < 0.01], whereas the two experimental conditions did not differ from each other. REM sleep in the NBTI-treated and recovery sleep groups had similar percentage increases (65 and 50%).