Glutamatergic CYLD deletion leads to aberrant excitatory activity in the basolateral amygdala:association with enhanced cued fear expression

Neuronal activity,synaptic transmission,and molecular changes in the basolateral amygdala play critical roles in fear memory.Cylindromatosis(CYLD)is a deubiquitinase that negatively regulates the nuclear factor kappa-B pathway.CYLD is well studied in non-neuronal cells,yet underinvestigated in the brain,where it is highly expressed.Emerging studies have shown involvement of CYLD in the remodeling of glutamatergic synapses,neuroinflammation,fear memory,and anxiety-and autism-like behaviors.However,the precise role of CYLD in glutamatergic neurons is largely unknown.Here,we first proposed involvement of CYLD in cued fear expression.We next constructed transgenic model mice with specific deletion of Cyld from glutamatergic neurons.Our results show that glutamatergic CYLD deficiency exaggerated the expression of cued fear in only male mice.Further,loss of CYLD in glutamatergic neurons resulted in enhanced neuronal activation,impaired excitatory synaptic transmission,and altered levels of glutamate receptors accompanied by over-activation of microglia in the basolateral amygdala of male mice.Altogether,our study suggests a critical role of glutamatergic CYLD in maintaining normal neuronal,synaptic,and microglial activation.This may contribute,at least in part,to cued fear expression.

Overexpression of Sirt6 ameliorates sleep deprivation induced-cognitive impairment by modulating glutamatergic neuron function

Sleep benefits the restoration of energy metabolism and thereby suppo rts neuronal plasticity and cognitive behaviors.Sirt6 is a NAD+-dependent protein deacetylase that has been recognized as an essential regulator of energy metabolism because it modulates various transcriptional regulators and metabolic enzymes.The aim of this study was to investigate the influence of Sirt6 on cerebral function after chronic sleep deprivation(CSD).We assigned C57BL/6J mice to control or two CSD groups and subjected them to AAV2/9-CMV-EGFP or AAV2/9-CMV-Sirt6-EGFP infection in the prelimbic cortex(PrL).We then assessed cerebral functional connectivity(FC) using resting-state functional MRI,neuron/astrocyte metabolism using a metabolic kinetics analysis;dendritic spine densities using sparse-labeling;and miniature excitato ry postsynaptic currents(mEPSCs) and action potential(AP) firing rates using whole-cell patchclamp recordings.In addition,we evaluated cognition via a comprehensive set of behavioral tests.Compared with controls,Sirt6 was significantly decreased(P<0.05) in the PrL after CSD,accompanied by cognitive deficits and decreased FC between the PrL and accumbens nucleus,piriform cortex,motor co rtex,somatosensory co rtex,olfactory tubercle,insular cortex,and cerebellum.Sirt6 ove rexpression reve rsed CSD-induced cognitive impairment and reduced FC.Our analysis of metabolic kinetics using [1-13C] glucose and [2-13C] acetate showed that CSD reduced neuronal Glu4and GABA2synthesis,which could be fully restored via forced Sirt6 expression.Furthermore,Sirt6 ove rexpression reversed CSD-induced decreases in AP firing rates as well as the frequency and amplitude of mEPSCs in PrL pyramidal neurons.These data indicate that Sirt6 can improve cognitive impairment after CSD by regulating the PrL-associated FC network,neuronal glucose metabolism,and glutamatergic neurotransmission.Thus,Sirt6 activation may have potential as a novel strategy for treating sleep disorder-related diseases.

Optogenetic activation of glutamatergic neu⁃rons in somatosensory cortex promotes remy⁃elination in ischemic vascular dementia

OBJECTIVE Chronic cerebral hy⁃poperfusion can lead to progressive demyelin⁃ation and ischemic vascular dementia,yet there are no effective treatments.METHODS Magnetic resonance imaging was employed in patients with white matter damage,and optogenetics and skin stroking were exerted to activate glutamater⁃gic neurons in the somatosensory cortex in a clas⁃sical mouse model of ischemia vascular dementia.RESULTS White matter damage was correlated with disrupted cortical structure from MRI results.In a mouse model,activating glutamatergic neu⁃rons in the somatosensory cortex promotes prolif⁃eration of OPCs and remyelination to rescue cog⁃nitive impairment after chronic cerebral hypoper⁃fusion.Such therapeutic action was limited to stimulation with moderate intensity at the upper layers of the cortex,but was achieved over a wide time window after ischemia.Mechanistically,enhanced glutamatergic neuron-OPC functional synaptic connections are required for protection from activation of cortical glutamatergic neurons.Finally,skin stroking activation of the somatosen⁃sory cortex,an easier approach for clinical trans⁃lation,promoted OPC proliferation and remyelin⁃ation as well as cognitive recovery after cerebral hypoperfusion.CONCLUSION Activation of gluta⁃matergic neurons in the somatosensory cortex may serve as novel approaches for treating isch⁃emic vascular dementia through precise modula⁃tion of glutamatergic neuron-OPC circuits.

Chemogenetic activation of sublaterodorsal tegmental glutamatergic neurons alleviates rapid eye movement sleep behavior disorder symptoms in a chronic rat model of Parkinson disease

Rapid eye movement(REM)sleep behavior disorder(RBD)is a parasomnia that is featured by elevated motor behaviors and dream enactments during REM sleep.Clinical observations show that RBD bears significant relevance with several synucleinopathies such as Lewy body dementia and Parkinson disease(PD),and often develops prior to their diagnosis.Being a potential biomarker of PD,investigating the relationship of RBD symptoms and their emergence in developing PD would provide insight intoits pathogenesis.Here,in a chronic model of PD,rats with daily rotenone treatment exhibited key RBD features,including elevated sleep muscle tone,sleep fragmentation and EEG slowing at different time points.Based on detectedearly alpha synuclein aggregation and neural apoptosis in the sublaterodorsal tegmental nucleus(SLD),an area known to promote REM sleep and maintain sleep muscle atonia,the possible involvement of SLD glutamatergic neurons was interrogated.Via chemogenetic activation of SLD glutamatergic neurons,key RBD symptoms and EEG slowing in REM sleep were alleviated.These results are consistent with a progressive degeneration in REM sleep promoting pathways.Our findings provide a foundation for further studies into RBD and its relationship to neurodegenerative diseases.

Two types of auditory glutamatergic synapses and their implications for repairing damaged central auditory pathways

For the mammalian brain to process and decipher the rich panoply of sounds that abound in the world, nature has evolved an elegant collection of neural circuits dedicated to this task. Indeed, the complexity, variety and number of neural pathways devoted to computing auditory information is unique among sensory modalities （Kaas, 2008）. After the initial sensorineural encoding of sound at the level of the cochlea, auditory information is processed in several lower brainstem centers and eventually converges in the midbrain, at the level of the inferior colliculus （Wenstrup, 2005）, Subsequently, auditory information is transferred through the thalamus, the medial geniculate body, and then the auditory cortex （Winer et al., 2005; Razak and Fuzessery, 2010; Hackett, 2011; Lee and Sherman, 2011; Lee and Winer, 2011;

Central Glutamatergic-Purinergic System Importance in Brain/Neural Plasticity

The proteolysis of the extracellular matrix plays a key role in the synaptic neuroplasticity of the central nervous system (CNS), which results in learning and memory. Proteases from the serine family and metalloproteinases of the extracellular matrix are localized within the synapses and are released into the extracellular space in proportion to the degree of neuronal excitation. These enzymes cause changes in the morphology, shape and size, and the overall number of synapses and synthesize new synaptic connections. The proteinase also changes the function of receptors, and consequently, the secretion of neurotransmitter/neuromodulator from the presynaptic glutamatergic and/or purinergic elements are either strengthened or weakened. Neuroglia involved in homeostasis, melanin synthesis and defense of the brain contain different combinations of purinergic receptors, which contributes to many neurotransmitters. This review summarizes a concept of brain plasticity, the role of ATP and P2 receptors interaction with glutamatergic system during plasticity of the brain in the one hand and after physical exercise in the other, which may be triggering phenomena facilitative synaptic plasticity as well as potentiates an personal efficiency to react to biobehavioral adaptation and disorders.

Glutamatergic neurons of piriform cortex delay induction of inhalational general anesthesia

Since their clinical application in the 1840s,the greatest mystery surrounding general anesthesia(GA)is how different kinds of general anesthetics cause reversible unconsciousness,and the precise neural mechanisms underlying the processes.Over past years,although many studies revealed the roles of cortex,thalamus,brainstem,especially the sleep-wake circuits in GA-induced loss of consciousness(LOC),the full picture of the neural circuit mechanism of GA is still largely unknown.Recent studies have focused on the importance of other brain regions.Here,we report that the activity of glutamatergic(Glu)neurons in the piriform cortex(PC),a critical brain region for odor encoding,began to increase during the LOC of GA and gradually recovered after recovery of consciousness.Chemical lesions of the anterior PC(APC)neurons accelerated the induction time of isoflurane anesthesia.Chemogenetic and optogenetic activation of APcGlu neurons prolonged isoflurane and sevoflurane anesthesia induction,whereas APcclu neuron inhibition displayed the opposite effects.Moreover,the modification of APcclu neurons did not affect the induction or emergence time of propofol GA.In addition,odor processing may be partially involved in the induction of isoflurane and sevofurane GA regulated by APCclu neurons.In conclusion,our findings reveal a critical role of APCGlu neurons in inhalational GA induction.

MDGA2 Constrains Glutamatergic Inputs Selectively onto CA1 Pyramidal Neurons to Optimize Neural Circuits for Plasticity,Memory,and Social Behavior

Synapse organizers are essential for the development,transmission,and plasticity of synapses.Acting as rare synapse suppressors,the MAM domain containing glycosylphosphatidylinositol anchor(MDGA)proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex.A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with autism.However,MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory synapses.Differentiating the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective strategy.To address this,we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal neurons.Here we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature hippocampus.Conditional deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials,vesicular glutamate transporter 1 intensity,and neuronal excitability.These effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter intensity.Functionally,evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic inputs.At a behavioral level,memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired,consistent with deficits in long-term potentiation in the CA3-CA1 pathway.Social affiliation,a behavioral analog of social deficits in autism,was similarly compromised.These results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits,thereby optimizing this network for plasticity,cognition,and social behaviors.

Sodium Leak Channel in Glutamatergic Neurons of the Lateral Parabrachial Nucleus Helps to Maintain Respiratory Frequency Under Sevoflurane Anesthesia

The lateral parabrachial nucleus(PBL)is implicated in the regulation of respiratory activity.Sodium leak channel(NALCN)mutations disrupt the respiratory rhythm and influence anesthetic sensitivity in both rodents and humans.Here,we investigated whether the NALCN in PBL glutamatergic neurons maintains respiratory function under general anesthesia.Our results showed that chemogenetic activation of PBL glutamatergic neurons increased the respiratory frequency(RF)in mice;whereas chemogenetic inhibition suppressed RF.NALCN knockdown in PBL glutamatergic neurons but not GABAergic neurons significantly reduced RF under physiological conditions and caused more respiratory suppression under sevoflurane anesthesia.NALCN knockdown in PBL glutamatergic neurons did not further exacerbate the respiratory suppression induced by propofol or morphine.Under sevoflurane anesthesia,painful stimuli rapidly increased the RF,which was not affected by NALCN knockdown in PBL glutamatergic neurons.This study suggested that the NALCN is a key ion channel in PBL glutamatergic neurons that maintains respiratory frequency under volatile anesthetic sevoflurane but not intravenous anesthetic propofol.

Activation of glutamatergic neurons in the somatosensory cortex promotes remyelination in ischemic vascular dementia

Chronic cerebral hypoperfusion can cause progressive demyelination as well as ischemic vascular dementia,however no effective treatments are available.Here,based on magnetic resonance imaging studies of patients with white matter damage,we found that this damage is associated with disorganized cortical structure.In a mouse model,optogenetic activation of glutamatergic neurons in the somatosensory cortex significantly promoted oligodendrocyte progenitor cell(OPC)proliferation,remyelination in the corpus callosum,and recovery of cognitive ability after cerebral hypoperfusion.The therapeutic effect of such stimulation was restricted to the upper layers of the cortex,but also spanned a wide time window after ischemia.Mechanistically,enhancement of glutamatergic neuron-OPC functional synaptic connections is required to achieve the protection effect of activating cortical glutamatergic neurons.Additionally,skin stroking,an easier method to translate into clinical practice,activated the somatosensory cortex,thereby promoting OPC proliferation,remyelination and cognitive recovery following cerebral hypoperfusion.In summary,we demonstrated that activating glutamatergic neurons in the somatosensory cortex promotes the proliferation of OPCs and remyelination to recover cognitive function after chronic cerebral hypoperfusion.It should be noted that this activation may provide new approaches for treating ischemic vascular dementia via the precise regulation of glutamatergic neuron-OPC circuits.

Glutamatergic neurons in the paraventricular nucleus of the hypothalamus participate in the regulation of visceral pain induced by pancreatic cancer in mice

Background:Visceral pain induced by pancreatic cancer seriously affects patients’quality of life,and there is no effective treatment,because the mechanism of its neural circuit is unknown.Therefore,the aim of this study is to explore the main neural circuit mechanism regulating visceral pain induced by pancreatic cancer in mice.Methods:The mouse model of pancreatic cancer visceral pain was established on C57BL/6N mice by pancreatic injection of mPAKPC-luc cells.Abdominal mechanical hyperalgesia and hunch score were performed to assess visceral pain;the pseudorabies virus(PRV)was used to identify the brain regions innervating the pancreas;the c-fos co-labeling method was used to ascertain the types of activated neurons;in vitro electrophysiological patch-clamp technique was used to record the electrophysiological activity of specific neurons;the calcium imaging technique was used to determine the calcium activity of specific neurons;specific neuron destruction and chemogenetics methods were used to explore whether specific neurons were involved in visceral pain induced by pancreatic cancer.Results:The PRV injected into the pancreas was detected in the paraventricular nucleus of the hypothalamus(PVN).Immunofluorescence staining showed that the majority of c-fos were co-labeled with glutamatergic neurons in the PVN.In vitro electrophysiological results showed that the firing frequency of glutamatergic neurons in the PVN was increased.The calcium imaging results showed that the calcium activity of glutamatergic neurons in the PVN was enhanced.Both specific destruction of glutamatergic neurons and chemogenetics inhibition of glutamatergic neurons in the PVN alleviated visceral pain induced by pancreatic cancer.Conclusions:Glutamatergic neurons in the PVN participate in the regulation of visceral pain induced by pancreatic cancer in mice,providing new insights for the discovery of effective targets for the treatment of pancreatic cancer visceral pain.

Lateral Hypothalamic Area Glutamatergic Neurons and Their Projections to the Lateral Habenula Modulate the Anesthetic Potency of Isoflurane in Mice

The lateral hypothalamic area(LHA)plays a pivotal role in regulating consciousness transition,in which orexinergic neurons,GABAergic neurons,and melanin-concentrating hormone neurons are involved.Glutamatergic neurons have a large population in the LHA,but their anesthesia-related effect has not been explored.Here,we found that genetic ablation of LHA glutamatergic neurons shortened the induction time and prolonged the recovery time of isoflurane anesthesia in mice.In contrast,chemogenetic activation of LHA glutamatergic neurons increased the time to anesthesia and decreased the time to recovery.Optogenetic activation of LHA glutamatergic neurons during the maintenance of anesthesia reduced the burst suppression pattern of the electroencephalogram(EEG)and shifted EEG features to an arousal pattern.Photostimulation of LHA glutamatergic projections to the lateral habenula(LHb)also facilitated the emergence from anesthesia and the transition of anesthesia depth to a lighter level.Collectively,LHA glutamatergic neurons and their projections to the LHb regulate anesthetic potency and EEG features.

Develop a 3D neurological disease model of human cortical glutamatergic neurons using micropillar-based scaffolds

Establishing an effective three-dimensional(3D) in vitro culture system to better model human neurological diseases is desirable, since the human brain is a 3D structure. Here, we demonstrated the development of a polydimethylsiloxane(PDMS) pillar-based 3D scaffold that mimicked the 3D microenvironment of the brain. We utilized this scaffold for the growth of human cortical glutamatergic neurons that were differentiated from human pluripotent stem cells. In comparison with the 2D culture, we demonstrated that the developed 3D culture promoted the maturation of human cortical glutamatergic neurons by showing significantly more MAP2 and less Ki67 expression. Based on this 3D culture system,we further developed an in vitro disease-like model of traumatic brain injury(TBI), which showed a robust increase of glutamate-release from the neurons, in response to mechanical impacts, recapitulating the critical pathology of TBI. The increased glutamate-release from our 3D culture model was attenuated by the treatment of neural protective drugs, memantine or nimodipine. The established 3D in vitro human neural culture system and TBI-like model may be used to facilitate mechanistic studies and drug screening for neurotrauma or other neurological diseases.

Sinoatrial node pacemaker cells share dominant biological properties with glutamatergic neurons

Activation of the heart normally begins in the sinoatrial node(SAN).Electrical impulses spontaneously released by SAN pacemaker cells(SANPCs)trigger the contraction of the heart.However,the cellular nature of SANPCs remains controversial.Here,we report that SANPCs exhibit glutamatergic neuron-like properties.By comparing the single-cell transcriptome of SANPCs with that of cells from primary visual cortex in mouse,we found that SANPCs co-clustered with cortical neurons.Tissue and cellular imaging confirmed that SANPCs contained key elements of glutamatergic neurotransmitter system,expressing genes encoding glutamate synthesis pathway(G/s),ionotropic and metabotropic glutamate receptors(Grina,Gria3,Grm1 and Grm5)t and glutamate transporters(Slc17a7).SANPCs highly expressed cell markers of glutamatergic neurons(Snap25 and S/-c17a7)t whereas Gad1,a marker of GABAergic neurons,was negative.Functional studies revealed that inhibition of glutamate receptors or transporters reduced spontaneous pacing frequency of isolated SAN tissues and spontaneous Ca2+transients frequency in single SANPC.Collectively,our work suggests that SANPCs share dominant biological properties with glutamatergic neurons,and the glutamatergic neurotransmitter system may act as an intrinsic regulation module of heart rhythm,which provides a potential intervention target for pacemaker cell-associated arrhythmias.

Rapid-onset antidepressant efficacy of glutamatergic system modulators:The neural plasticity hypothesis of depression

Depression is a devastating psychiatric disorder widely attributed to defi cient monoaminergic signaling in the central nervous system. However,most clinical antidepressants enhance monoaminergic neurotransmission with little delay but require 4-8 weeks to reach therapeutic efficacy,a paradox suggesting that the monoaminergic hypothesis of depression is an oversimplifi cation. In contrast to the antidepressants targeting the monoaminergic system,a single dose of the N-methyl-D-aspartate receptor（NMDAR） antagonist ketamine produces rapid（within 2 h） and sustained（over 7 days） antidepressant effi cacy in treatment-resistant patients. Glutamatergic transmission mediated by NMDARs is critical for experience-dependent synaptic plasticity and learning,processes that can be modifi ed indirectly by the monoaminergic system. To better understand the mechanisms of action of the new antidepressants like ketamine,we review and compare the monoaminergic and glutamatergic antidepressants,with emphasis on neural plasticity. The pathogenesis of depression may involve maladaptive neural plasticity in glutamatergic circuits that may serve as a new class of targets to produce rapid antidepressant effects.

Development of glutamatergic innervation during maturation of adult-born neurons

The dentate gyrus is the entrance of the hippocampal formation and a primary target of excitatory afferents from the entorhinal cortex that carry spatial and sensory information. Mounting evidence suggests that continual adult neurogenesis contributes to appropriate processing of cortical information. The ongoing integration of adult born neurons dynamically modulates connectivity of the network, potentially contributing to dentate cognitive function. Here we review the current understanding of how glutamatergie innervation develops during the progression of adult-born neuron maturation. Summarizing the developmental stages of dentate neurogenesis, we also demonstrate that new neurons at an immature stage of maturation begin to process afferent activity from both medial and lateral entorhinal cortices.

How do lateral septum projections to the ventral CA1 influence sociability?

Social dysfunction is a risk factor for several neuropsychiatric illnesses.Previous studies have shown that the lateral septum(LS)-related pathway plays a critical role in mediating social behaviors.Howeve r,the role of the connections between the LS and its downstream brain regions in social behavio rs remains unclea r.In this study,we conducted a three-chamber test using electrophysiological and chemogenetic approaches in mice to determine how LS projections to ventral CA1(vCA1)influence sociability.Our res ults showed that gamma-aminobutyric acid(GABA)-e rgic neuro ns were activated following social experience,and that social behavio rs were enhanced by chemogenetic modulation of these neurons.Moreover,LS GABAergic neurons extended their functional neural connections via vCA1 glutamatergic pyramidal neurons,and regulating LSGABA→vCA1Gluneural projections affected social behaviors,which were impeded by suppressing LSprojecting vCA1 neuronal activity or inhibiting GABAAreceptors in vCA1.These findings support the hypothesis that LS inputs to the vCA1 can control social prefe rences and social novelty behaviors.These findings provide new insights rega rding the neural circuits that regulate sociability.

Cyanidin-3-O-glucoside alleviates trimethyltin chloride-induced neurodegeneration by maintaining glutamate homeostasis through modulation of the gut microbiota

Trimethyltin chloride(TMT)is a potent neurotoxin to cause neurodegeneration,especially in hippocampus.This study aimed to identify dietary components that can effectively attenuate TMT-induced neurodegeneration in humans.The predominant anthocyanin in human diets,cyanidin-3-O-glucoside(C3G,5 or 50 mg/kg),was given to mice for 16 days,and TMT(2.7 mg/kg)was injected intraperitoneally once on the eighth day.C3G(50 mg/kg)significantly alleviated TMT-induced seizures and subsequent cognitive impairment by ameliorating hippocampal neurodegeneration and synaptic dysfunction.Furthermore,C3G treatment restored glutamate homeostasis in brain and reversed glutamine synthetase(GS)inhibition in reactive astrogliosis and neuroinflammation,which are critical for C3G's neuroprotective effects.Notably,C3G decreased the lipopolysaccharide,tumor necrosis factor-α,interleukin-6,and interleukin-1βlevels in the mice,which potentially by modulating the relative abundance of Atopobiaceae and Lachnospiraceae in the gut.C3G may be a promising and practical dietary component for reducing TMT-induced neurodegeneration.

GPR17 modulates anxiety-like behaviors via basolateral amygdala to ventral hippocampal CA1 glutamatergic projection

Anxiety disorders are one of the most epidemic and chronic psychiatric disorders.An incom-plete understanding of anxiety pathophysiology has limited the development of highly effective drugs against these disorders.GPR17 has been shown to be involved in multiple sclerosis and some acute brain injury disorders.However,no study has investigated the role of GPR17 in psychiatric disorders.In a well-established chronic restraint stress(CRS)mouse model,using a combination of pharmacological and molecular biology techniques,viral tracing,in vitro electrophysiology recordings,in vivo fiber photom-etry,chemogenetic manipulations and behavioral tests,we demonstrated that CRS induced anxiety-like behaviors and increased the expression of GPR17 in basolateral amygdala(BLA)glutamatergic neurons.Inhibition of GPR17 by cangrelor or knockdown of GPR17 by adeno-associated virus in BLA glutama-tergic neurons effectively improved anxiety-like behaviors.Overexpression of GPR17 in BLA glutama-tergic neurons increased the susceptibility to anxiety-like behaviors.What's more,BLA glutamatergic neuronal activity was required for anxiolytic-like effects of GPR17 antagonist and GPR17 modulated anxiety-like behaviors via BLA to ventral hippocampal CAl glutamatergic projection.Our study finds for the first and highlights the new role of GPR17 in regulating anxiety-like behaviors and it might be a novel potential target for therapy of anxiety disorders.

Sleep disorders in Alzheimer’s disease:the predictive roles and potential mechanisms

Sleep disorders are common in patients with Alzheimer’s disease,and can even occur in patients with amnestic mild cognitive impairment,which appears before Alzheimer’s disease.Sleep disorders further impair cognitive function and accelerate the accumulation of amyloid-βand tau in patients with Alzheimer’s disease.At present,sleep disorders are considered as a risk factor for,and may be a predictor of,Alzheimer’s disease development.Given that sleep disorders are encountered in other types of dementia and psychiatric conditions,sleep-related biomarkers to predict Alzheimer’s disease need to have high specificity and sensitivity.Here,we summarize the major Alzheimer’s disease-specific sleep changes,including abnormal non-rapid eye movement sleep,sleep fragmentation,and sleep-disordered breathing,and describe their ability to predict the onset of Alzheimer’s disease at its earliest stages.Understanding the mechanisms underlying these sleep changes is also crucial if we are to clarify the role of sleep in Alzheimer’s disease.This paper therefore explores some potential mechanisms that may contribute to sleep disorders,including dysregulation of the orexinergic,glutamatergic,andγ-aminobutyric acid systems and the circadian rhythm,together with amyloid-βaccumulation.This review could provide a theoretical basis for the development of drugs to treat Alzheimer’s disease based on sleep disorders in future work.