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• SD causes microglial activation and Keap1-Nrf2 reduction in the mouse hippocampus. • SD alters theta, beta, and high gamma oscillations in the mouse hippocampus. • SD induces anxiety-like and depressive-like behavior in mice. • Minocycline inhibits microglial activation and Keap1-Nrf2 reduction in SD mice. • Minocycline normalizes brain oscillations and behavioral alteration in SD mice. Sleep deprivation (SD) is a hallmark of modern society and associated with many neuropsychiatric disorders, including depression and anxiety. However, the cellular and molecular mechanisms underlying SD-associated depression and anxiety remain elusive. Does the neuroinflammation play a role in mediating the effects of SD? In this study, we investigated SD-induced cellular and molecular alterations in the hippocampus and asked whether treatment with an anti-inflammatory drug, minocycline, could attenuate these alterations. We found that SD animals exhibit activated microglia and decreased levels of Keap1 and Nrf2 (antioxidant and anti-inflammatory factors) in the hippocampus. In vivo local field potential recordings show decreased theta and beta oscillations, but increased high gamma oscillations, as a result of SD. Behavioral analysis revealed increased immobility time in the forced swim and tail suspension tests, and decreased sucrose intake in SD mice, all indicative of depressive-like behavior. Moreover, open field test and elevated plus maze test results indicated that SD increases anxiety-like behavior. Interestingly, treatment with the microglial modulator minocycline prevented SD-induced microglial activation, restored Keap1 and Nrf2 levels, normalized neuronal oscillations, and alleviated depressive-like and anxiety-like behavior. The present study reveals that microglial activation and Keap1-Nrf2 signaling play a crucial role in SD-induced behavioral alteration, and that minocycline treatment has a protective effect on these alterations. [ABSTRACT FROM AUTHOR]

• Mitophagy, a selective type of autophagy, eliminates selectively damaged/weakened mitochondria. • Impaired mitophagy emerges in early AD progression. • Compromised mitophagy contributes to mitochondrial dysfunction and abnormal energy metabolism in AD. • Targeting mitophagy could be a promising therapeutic avenue for the prevention and treatment of AD. Alzheimer's disease (AD) is an age-dependent, incurable mental illness that is associated with the accumulation of aggregates of amyloid-beta (Aβ) and hyperphosphorylated tau fragments (p-tau). Detailed studies on postmortem AD brains, cell lines, and mouse models of AD have shown that numerous cellular alterations, including mitochondrial deficits, synaptic disruption and glial/astrocytic activation, are involved in the disease process. Mitophagy is a cellular process by which damaged/weakened mitochondria are selectively eliminated from the cell. In AD, impairments in mitophagy trigger the gradual accumulation of defective mitochondria. This review will focus on the recent progress in understanding the molecular mechanisms and pathological role of mitophagy and its implications for AD pathogenesis. We will also discuss the novel concept of the regulation of mitophagy as a therapeutic avenue for the prevention and treatment of AD. [ABSTRACT FROM AUTHOR]

Ischemic stroke induced inflammatory responses contribute significantly to neuronal damage and stroke outcomes. CD200 ligand and its receptor, CD200R, constitute an endogenous inhibitory signaling that is being increasingly recognized in studies of neuroinflammation in various central nervous system disorders. CD200 is a type 1 membrane glycoprotein that is broadly expressed by endothelia and neurons in the brain. In the present study, we have examined the role of endothelial CD200 signaling in acute ischemic stroke. Endothelial CD200 conditional knock out (CKO) mice were generated by breeding CD200 gene floxed mice with Cdh5Cre mice. The mice were subjected to a 60-min transient middle cerebral artery occlusion (MCAO). Flow cytometry, Immunohistochemical staining, and Western blotting were performed to assess the post-stroke inflammation; stroke outcomes (infarct volume and neurobehavioral deficits) were evaluated at 72 h after MCAO. We found CD200R was near-null expressed on microglia at 24 h after stoke. Endothelial CKO of CD200 had no impact on peripheral immune cell development. Immunohistochemical staining confirmed CD200 was expressed on CD200 floxed but not on CD200 CKO endothelia. CD200 CKO mice exhibited larger infarct size, worse neurological deficit scores (NDS), and more deficits in the adhesive removal when compared with control mice, 72 h after MCAO. Western blot results showed that endothelial CKO of CD200 did not change BBB protein expression. Together it suggests that endothelial CD200 signaling protects brains against ischemic injury through a mechanism not directly related to microglial activation. • CKO of endothelial CD200 does not change immune cell development. • Adult microglia express near null CD200R. • Endothelial CD200 signaling protects brains against ischemic injury. • BBB proteins are not affected by CD200 CKO. [ABSTRACT FROM AUTHOR]

• Sleep deprivation (SD) alters delta, theta and high-gamma oscillations in PFC of young AD mice. • SD increases excitatory postsynaptic signaling (NMDAR, GluR1, and CaMKII) in PFC of young AD mice. • SD alters dendritic morphology of PFC neurons in young AD mice. • SD reduces CREB levels in PFC of young AD mice. Emerging evidence suggests that sleep deprivation (SD) is a public health epidemic and increase the risk of Alzheimer's disease (AD) progression. However, the underlying mechanisms remain to be fully investigated. In this study, we investigate the impact of 72 h SD on the prefrontal cortex (PFC) of 3∼4-months-old APP/PS1 transgenic AD mice - at an age before the onset of plaque formation and memory decline. Our results reveal that SD alters delta, theta and high-gamma oscillations in the PFC, accompanied by increased levels of excitatory postsynaptic signaling (NMDAR, GluR1, and CaMKII) in AD mice. SD also caused alteration in the dendritic length and dendritic branches of PFC pyramidal neurons, accompanied by a reduction in neuroprotective agent CREB. This study suggests that failure to acquire adequate sleep could trigger an early electrophysiological, molecular, and morphological alteration in the PFC of AD mice. Therapeutic interventions that manipulate sleep by targeting these pathways may be a promising approach toward delaying the progression of this incurable disease. [ABSTRACT FROM AUTHOR]

• Sleep deprivation caused reduction of pCaMKII-pCREB-BDNF levels in PFC. • Sleep deprivation reduced neuronal excitability of PFC pyramidal neurons. • CTM treatment prevented SD-induced reduction of pCaMKII-pCREB-BDNF levels. • CTM treatment maintained neuronal excitability of PFC pyramidal neurons of SD animals. Curtailment of sleep in modern society leads to a spectrum of neuropsychiatric disorders. However, the molecular mechanisms underlying the effects of sleep deprivation (SD) remain elusive and currently there is no effective therapy to alleviate these effects. Here, we aimed to examine SD-induced cellular and molecular alterations in mouse prefrontal cortex (PFC) and whether subchronic citalopram (CTM) treatment can negate these alterations. Three-month-old C57BL/6 J mice were divided into control (Ctrl), SD, CTM alone and CTM + SD groups. CTM and CTM + SD group mice were treated with CTM for five consecutive days at a dose of 10 mg/kg per day before the experimental procedure. SD and CTM + SD group mice were sleep-deprived for 24 h using an automated treadmill method. We found that 24 h SD causes a marked reduction in the levels of phosphorylated calcium/calmodulin kinase II (pCaMKII), phosphorylated cyclic AMP-responsive element binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) in mouse PFC. Patch clamp recording of pyramidal neurons from acute PFC slices revealed that SD decreases the amplitude of miniature excitatory postsynaptic currents (mEPSCs), suggesting a SD-induced postsynaptic alteration. Interestingly, subchronic CTM treatment prevents such SD-induced reductions in pCaMKII, pCREB and BDNF levels, and in mEPSC amplitude. These data suggest that CTM offers neuroprotection against SD-induced molecular and electrophysiological alterations. [ABSTRACT FROM AUTHOR]

Abstract Recently there is increasing concern over the association between sleep deprivation (S-Dep) and depression. Mounting evidence suggests that S-Dep might be a risk factor for depression. However, underlying molecular mechanism remains elusive and currently there is no effective therapy to negate the effects of S-Dep. In this study, we aimed to examine whether subchronic treatment of citalopram (CTM), an antidepressant, can attenuate the negative effects of S-Dep in mice. Three-month-old C57BL/6J mice were divided into control, S-Dep, CTM control and CTM + S-Dep groups. CTM and CTM + S-Dep group treated with citalopram for 5 consecutive days at a dose of 10 mg/kg per day before experimental procedure. S-Dep and CTM + S-Dep group mice were sleep deprived for 24 h using an automated treadmill method. Our results revealed that S-Dep animals displayed an increased depressive-like behavior in forced swim, tail suspension and sucrose preference test and anxiety-like behavior in the open field and elevated plus maze, as well as disrupted spatial memory in Morris water maze. Western blotting analysis revealed that S-Dep caused reductions in the levels of the plasticity- and memory-related signaling molecules i.e. pCaMKII and pCREB in the hippocampus. Moreover, S-Dep animals showed synaptic plasticity deficits in the Schaffer collateral pathway. Interestingly, subchronic CTM treatment prevented S-Dep-induced decrease in pCaMKII and pCREB levels in the hippocampus. Furthermore, CTM treatment prevented S-Dep-induced deficits in synaptic plasticity, spatial memory, depressive-like behavior in sucrose preference test and anxiety-like behavior in open field test but not in force swim, tail suspension and elevated plus maze test. This data suggests differential effects of CTM on S-Dep-associated behavioral alterations and cognitive impairments. Highlights • Sleep deprivation induces depressive-like behavior in mice. • Sleep deprivation causes reduction of pCaMKII and pCREB in hippocampus. • Sleep deprivation disrupts hippocampal synaptic plasticity and spatial memory. • Citalopram prevents sleep-deprivation-induced reduction in pCaMKII and pCREB levels. • Citalopram prevents synaptic plasticity deficits, memory impairments and most of the behavioral alterations. [ABSTRACT FROM AUTHOR]