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Chronic sleep loss caused lots of health problems, also including cognition impairment. Tea is one of the most popular drinks when people stay up late. Nevertheless, the effects of tea on sleep deprivation-induced cognition impairment are still unclear. In the present study, we found 24-h sleep deprivation (S-DEP) increased membrane α-amino-3-hydroxy-5-methyl-4-isoxa-zolep-propionate (AMPA) receptor level through a tumor necrosis factor α (TNFα)-dependent pathway in hippocampi. Blocking elevated TNFα level can protect S-DEP mice from impaired learning ability according to behavioral test. Tea polyphenols, major active compounds in green tea, suppressed TNFα production through downregulating TNFα converting enzyme (TACE) level. Meanwhile, tea polyphenols treatment could ameliorate recognition impairment and anxiety-like behaviors in S-DEP mice. The aforementioned results demonstrate cognition protective effects of tea polyphenols in S-DEP mice model, which provide a theoretical basis for the treatments of S-DEP-induced cognition impairment by targeting the TACE/TNFα/AMPA pathway.

Prolonged stress induces neural maladaptations in mesolimbic dopamine (DA) system and produces emotional and behavioral disorders. However, the effects of stress on activity of DA neurons are diverse and complex that hinge on the type, duration, intensity, and controllability of stressors. Here, controlling the duration, intensity, and type of the stressors to be identical, we observed effects of stressor controllability on the activity of substantia nigra compacta (SNc) DA neurons in mice. We found that both lack and loss of control over shock enhance the basal activity and intrinsic excitability of SNc DA neurons via modulation of I h current, but not via corticosterone serum level. Moreover, loss of control over shock produces more significant enhancement in the basal activity of SNc DA neurons than that produced shock per se, and therefore attenuates the response to natural reward. This attenuation can be reversed by control over shock. These results indicate that although chronic stress per se tends to enhance the basal activity of SNc DA neurons, loss of control over the stressor is able to induce a larger enhancement in basal activity of SNc DA neurons and produce more severe behavioral deficits. However, control over stress ameliorates the deleterious effects of stress, highlighting the role of stress controllability. Significance statementThe impact of stress on the DA system significantly modifies immediate and guide future behaviors. Stress does not have unitary effects on VTA DA neurons, but the effects of stress controllability on SNc DA neurons are unclear. The present work studied the effects of controllability on the activity of SNc DA neurons by controlling the duration, intensity, and pattern of footshocks to be identical. The results show that loss of control over shock produces larger enhancement in basal activity of SNc DA neurons and worse behavioral deficits than what caused by uncontrollable shock per se. The results demonstrate the critical role of stress controllability in modulating activity of SNc DA neurons and inducing behavioral deficits.

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