Ionic mechanisms of the effects of sleep deprivation on excitability in hippocampal pyramidal neurons

It has been confirmed that sleep has a key role in learning and memory. Our previous study indicated that paradoxical sleep deprivation (PSD) impairs spatial learning ability of rats, and the decrease in membrane excitability of CA1 pyramidal neurons contributes to deficits in performing a spatial learning task. To investigate the further ionic mechanisms, the persistent sodium currents (INaP), the hyperpolarization-activated cation current (Ih), and their roles in neuron excitability were detected. PSD decreased INaP and suppressed spike ADP, which leads to the reduction of neuron excitability and to the increase of firing accommodation. In addition, PSD reduced the Ih amplitude and the rebound excitability of CA1 pyramidal neurons. The results of the present study suggested that Ih and INaP contributed to the inhibitory effect of PSD on neuron excitability, further influencing learning and memory processing. Modulating the ion channels and increasing the membrane excitability of hippocampal neurons are possible targets for preventing the effects of paradoxical sleep deprivation.