Time-dependent effect of nicotine exposure on glucose transport across the BBB in normal animals. [3H] D-Glucose transport (K
in; mL.sec−1.g−1) into brain was measured using in-situ brain perfusion. Animals were pre-exposed to nicotine for 1, 7 and 14 days. Data represent mean ± SEM, n = 5–6 animals, *P < 0.05, and ***P < 0.001 comparing the nicotine-treated groups and the corresponding sham group infused with saline for 14 days, using one way ANOVA analysis of the variance and Bonferonni’s multiple comparison test.