Figure 6.

Hypocretin is ineffective on miniature IPSCs. (A) IPSC traces at +10 mV, from a representative pyramidal neuron. Traces illustrate ∼60-s continuous recording before treatment (Control), in the presence of 0.5 μM TTX + 50 μM Cd²⁺ (TTX + Cd²⁺), in the presence of 0.5 μM TTX, 50 μM Cd²⁺, and 100 nM hypocretin 1 (Hypocretin + TTX + Cd²⁺), and after removal of hypocretin (Wash). In this experiment, treatment with TTX + Cd²⁺ revealed the miniature IPSC events, whose frequency was considerably lower than the frequency of the spontaneous IPSCs. Hypocretin did not significantly alter the frequency of these miniature events (as estimated with KS test; not shown). (B) Similar results were obtained in 6 total experiments. Bars give the average effect of the indicated treatments on the IPSC frequency, calculated for 2-min continuous recording at the steady state, in each indicated condition (n = 6). Hypocretin did not produce any significant increase in the miniature IPSC frequency, as detailed in the main text. (C) Average results obtained from 5 experiments carried out and analyzed as illustrated in (A) and (B), except that Cd²⁺ was not present. Hypocretin did not produce any significant alteration in the average frequency of the miniature IPSCs (statistics are given in the main text). Similar results were obtained in the presence of 500 nM hypocretin (n = 7).