Figure 2.

Responses to glucose of orexin neurons in K_2P channel KO mice. A, Typical current response of a orexin neuron recorded in the voltage-clamp mode in response to a 500 ms hyperpolarizing pulse to −100 mV from a holding potential of −60 mV. Notice the presence of a slowly activating inward current (I_h). B, Superimposed typical responses to depolarizing and hyperpolarizing pulses delivered from the resting potential of a orexin neuron recorded in the current-clamp mode. Notice that the discharge of action potential shows very few adaptation. C, Examples of typical pattern obtained in single cell multiplex RT-PCR from one presumed orexin neuron. Multiplex RT-PCR was performed as described by Guyon et al. (2005). A negative control without reverse transcriptase (NRT) was performed. D, Current-clamp recordings showing the effect of increases in glucose concentration from 0.2 to 4.5 mm in double TASK1^−/−TASK3^−/− (TASK^−/−) and triple TREK1^−/−TREK2^−/−TRAAK^−/− (TREK^−/−) orexin neurons. E, Mean maximum amplitude (+SEM) of the hyperpolarization recorded in control and KO mice (number of neurons tested in parenthesis).