Figure 3.

Effect of glucose applications on putative sleep-promoting VLPO neurons. A, Reversible inhibitory effect of decreasing extracellular glucose concentration from 5 to 1 mm on the spontaneous firing activity of a VLPO neuron recorded in loose-cell-attached configuration. B, Quantification of the excitatory effect of glucose (from 1 to 5 mm) on the spontaneous firing activity of glucose-responsive VLPO cells (n = 8). Data are presented as mean ± SEM. **p < 0.01, Wilcoxon test: ns. C, Dose–response relationship of the excitatory effect of glucose on glucose-sensitive VLPO cells. Data fit a Hill curve with an EC₅₀ of 4.06 mm and are presented as mean ± SEM with group sizes for each glucose concentration (1, 2.5, 5, 10, 25 mm). D, Reversible inhibitory effect of bath-applied NA (100 μm; right) on the spontaneous firing activity of the same cell shown in A characterized by a multipolar shape (left). Scale bar, 20 μm. E, Current-clamp recording of the same cell shown in A characterized by the presence of a potent LTS (*).