Figure 2.

A diagram summarizes the time courses of changes in synaptic efficacy of glutamatergic synapses on hypocretin neurons depending on the energy and arousal states in animals. (A) Synaptic efficacy is potentiated when animals are food-deprived and de-potentiated when they are fed or re-fed. Insets, miniature excitatory postsynaptic currents (mEPSCs) recorded in hypocretin neurons in fed (left) and fasted (right) mice. Traces are from Horvath and Gao (2005) with permission from Cell Metabolism. (B) Synaptic efficacy is potentiated when the arousal levels are high (sleep deprived) in animals and de-potentiated when they are sleeping. Insets, mEPSCs and AMPAR- and NMDAR-carried EPSCs recorded in hypocretin neurons from sleeping (left) and sleep-deprived (right) mice. Traces are from Rao et al. (2007) with permission from the Journal of Clinical Investigation.