Figure 4: Hypocretin/Orexin-A activates a TTX-insensitive L-type dependent membrane potential oscillation. | Scientific Reports

Figure 4: Hypocretin/Orexin-A activates a TTX-insensitive L-type dependent membrane potential oscillation.

From: Hypocretin/Orexin Peptides Excite Rat Neuroendocrine Dopamine Neurons through Orexin 2 Receptor-Mediated Activation of a Mixed Cation Current

Figure 4

(A) Current clamp recording of an oscillating TIDA neuron in the continuous presence of TTX. Prior to application of H/O-A, neuron was held at −65 mV with negative DC current injection and input resistance assessed with test pulses of −20pA. Application of H/O-A induced a depolarisation as in (Fig. 2B). However, in 3/9 (33%) of neurons tested, following peak depolarisation (green inset) H/O-A application induced a TTX insensitive membrane potential oscillation with late onset (red inset). Scale bar 5 mV/20 Sec; inset 4 mV/1 Sec. (B) Voltage clamp recording of a TIDA neuron in the continuous presence of TTX and following the application of H/O-A. Trace is filtered at 1 Hz with associated spectrogram shown underneath (Scale bar 4pA/30 Sec). The H/O-A induced, late onset TTX-insensitive oscillation, was abolished by the application of L-type Ca2+ channel blocker nimodipine (3/3, 100%). Shaded areas inset correspond to control (green) and nimodipine (red). Scale bar 4pA/30 Sec; 4pA/4 Sec.

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