Biology subjects

Diering, G. H.

Publications and source records attributed to Diering, G. H..

10 recordsLinked to original sources

bioRxiv2026

Diphenhydramine Disrupts Sleep Architecture in 5XFAD Alzheimers Disease Model and Wild-Type Mice

Sleep disruption is common in Alzheimers disease (AD). Diphenhydramine (DPH), a first-generation antihistamine with anticholinergic properties, is widely used as an over-the-counter sleep aid. We tested whether chronic DPH treatment alters sleep architecture in 5XFAD and wild-type mice. Female 5XFAD (n=16) and wild-type (WT) littermates (n=14) were implanted with wireless telemetry recording devices to measure electroencephalography (EEG), electromyography (EMG), temperature, and activity continuously. After a 24h baseline recording at 5 months of age, mice received oral DPH (10 mg/kg) or vehicle at ZT0 for one month. After this chronic treatment, sleep was recorded continuously for 48h during ongoing dosing. Sleep was scored as rapid eye movement (REM), non-rapid eye movement (NREM) 1, NREM2, or wake. A survival curve analysis was used to investigate the microarchitecture of sleep phases after chronic diphenhydramine treatment. At baseline, 5XFAD mice had more time in NREM1 than WT controls and had shorter REM and NREM2 bouts. Chronic DPH treatment fragmented NREM2 in both genotypes, reducing long NREM2 bouts. DPH increased total duration of NREM1 and REM during the active phase, which is analogous to daytime drowsiness in humans. DPH did not rescue 5XFAD sleep deficits; instead, DPH treatment exacerbated NREM2 fragmentation. Overall, chronic DPH use degrades sleep quality and increases fragmentation in both WT and AD-model mice, which questions the use of sedating anticholinergics as sleep aids, especially in AD.

neuroscience↗

bioRxiv2025

Unbiased genetics identifies a glutamatergic signaling network as a mediator of daily sleep patterns.

Sleep is a fundamental, conserved behavior important for survival. In many species, sleep behavior is controlled by poorly understood interactions between a system of circadian rhythms (CR), which promote sleep at ecologically appropriate times, and a homeostatic sleep drive that accumulates with time awake. The CR is a cellular phenomenon, driven by molecular oscillations of "clock genes" in nearly all cells. Emerging evidence indicates neuronal synapses are a key locus for the accumulation and resolution of sleep need, supporting a cellular basis of sleep need. Indeed, efforts to understand the genetic basis of sleep need identified Homer1a, a regulator of synapse homeostasis. To develop further insight into the genetic basis of sleep regulation, we measured daily sleep patterns in genetically diverse strains of mice from the Collaborative Cross. Strains with 1) highly consolidated light-phase sleep, or 2) fragmented, arrhythmic sleep, were identified for genetic analysis using quantitative trait loci (QTL) mapping. Excitingly, in F2 hybrids, 19 of 32 metrics of sleep and circadian behavior mapped to a narrow QTL containing GRM5, a postsynaptic glutamate receptor and binding partner of Homer1a, and GCPII, an astrocytic enzyme that regulates NAAG, a peptide agonist for the presynaptic/astrocytic glutamate receptor GRM3. Collectively, these genes form a coordinated glutamatergic signaling network across the tri-partite synapse. Pharmacology targeting GRM5, GCPII, and GRM3 strongly modulated sleep, functionally validating them as sleep-regulating genes. Our findings support a model in which synapses act as a cellular site for integration of circadian and sleep-need signals to regulate daily sleep patterns. Significance StatementSleep is a fundamental pillar of human health. Restorative sleep is supported by circadian rhythms (CR). Sleep and CR disruptions are prevalent in neuropsychiatric conditions and are increasingly understood as causal drivers of altered brain function and behavior. Therefore, sleep and CR are attractive therapeutic targets to improve health. However, the basic biological mechanisms that couple our need to sleep with the CR are not understood. Genetic discovery using diverse strains of mice identifies a glutamatergic signaling network coordinated across the synapse as an underlying genetic basis for daily sleep patterns. This work builds upon a growing body showing that excitatory synapses are a cellular site for the resolution of sleep need and interaction with the CR.

neuroscience↗

bioRxiv2024

Neurons and astrocytes have distinct organelle signatures and responses to stress

Neurons and astrocytes play critical yet divergent roles in brain physiology and neurological conditions. Intracellular organelles are integral to cellular function. However, an in-depth characterization of organelles in live brain cells has not been performed. Here, we used multispectral imaging to simultaneously visualize six organelles - endoplasmic reticulum (ER), lysosomes, mitochondria, peroxisomes, Golgi, and lipid droplets - in live primary rodent neurons and astrocytes. We generated a dataset of 173 Z-stack and 99 time-lapse images accompanied by quantitative analysis of 1418 metrics (the "organelle signature"). Comparative analysis revealed clear cell-type specificity in organelle morphology and interactions. Neurons were characterized by prominent mitochondrial composition and interactions, while astrocytes contained more lysosomes and lipid droplet interactions. Additionally, neurons displayed a more robust organelle response than astrocytes to acute oxidative or ER stress. Our data provide a systems-level characterization of neuron and astrocyte organelles that can be a reference for understanding cell- type-specific physiology and disease.

cell biology↗

bioRxiv2024

Analysis of hepatic lentiviral vector transduction; implications on preclinical studies and clinical gene therapy protocols.

Lentiviral vector-transduced T-cells were approved by the FDA as gene therapy anti-cancer medications. Little is known about the host genetic variation effects on the safety and efficacy of the lentiviral vector gene delivery system. To narrow this knowledge-gap, we characterized hepatic gene delivery by lentiviral vectors across the Collaborative Cross (CC) mouse genetic reference population. For 24 weeks, we periodically measured hepatic luciferase expression from lentiviral vectors in 41 CC mouse strains. Hepatic and splenic vector copy numbers were determined. We report that CC mouse strains showed highly diverse outcomes following lentiviral gene delivery. For the first time, moderate correlation between mouse strain-specific sleeping patterns and transduction efficiency was observed. We associated two quantitative trait loci (QTLs) with intra-strain variations in transduction phenotypes, which mechanistically relates to the phenomenon of metastable epialleles. An additional QTL was associated with the kinetics of hepatic transgene expression. Genes comprised in the above QTLs are potential targets to personalize gene therapy protocols. Importantly, we identified two mouse strains that open new directions in characterizing continuous viral vector silencing and HIV latency. Our findings suggest that wide-range patient-specific outcomes of viral vector-based gene therapy should be expected. Thus, novel escalating dose-based clinical protocols should be considered.

genetics↗

bioRxiv2023

Synapses are uniquely vulnerable to sleep loss during brain development while maturation confers resilience

Sleep is an essential behavior that supports lifelong brain health and cognition. Neuronal synapses are a major target for restorative sleep function and a locus of dysfunction in response to sleep deprivation (SD). Synapse density is highly dynamic during development, becoming stabilized with maturation to adulthood, suggesting sleep exerts distinct synaptic functions between development and adulthood. Importantly, problems with sleep are common in neurodevelopmental disorders including autism spectrum disorder (ASD). Moreover, early life sleep disruption in animal models causes long lasting changes in adult behavior. Different plasticity engaged during sleep necessarily implies that developing and adult synapses will show differential vulnerability to SD. To investigate distinct sleep functions and mechanisms of vulnerability to SD across development, we systematically examined the behavioral and molecular responses to acute SD between juvenile (P21-28), adolescent (P42-49) and adult (P70-100) mice of both sexes. Compared to adults, juveniles lack robust adaptations to SD, precipitating cognitive deficits in the novel object recognition test. Subcellular fractionation, combined with proteome and phosphoproteome analysis revealed the developing synapse is profoundly vulnerable to SD, whereas adults exhibit comparative resilience. SD in juveniles, and not older mice, aberrantly drives induction of synapse potentiation, synaptogenesis, and expression of peri-neuronal nets. Our analysis further reveals the developing synapse as a convergent node between vulnerability to SD and ASD genetic risk. Together, our systematic analysis supports a distinct developmental function of sleep and reveals how sleep disruption impacts key aspects of brain development, providing mechanistic insights for ASD susceptibility. Significance StatementSleep is a fundamental pillar of lifelong health. Sleep disruption is commonly associated with neurodevelopmental conditions including autism spectrum disorder (ASD) and schizophrenia. Therefore, understanding the vulnerabilities associated with developmental sleep loss is an essential research question. Here we systemically examine the molecular and behavioral consequence of sleep deprivation (SD) in developing and adult mice. Compared to adults, developing mice show absent or blunted adaptive responses to SD, and heightened sensitivity to SD-induced cognitive deficits. Our molecular analysis indicates sleep plays an important role in key aspects of brain development including synaptogenesis, and that the effects of SD converge on nodes of genetic risk for ASD. This study provides new insights into the role of sleep in healthy brain development.

neuroscience↗

bioRxiv2023

Sleep disruption precedes forebrain synaptic Tau burden and contributes to cognitive decline in a sex-dependent manner in the P301S Tau transgenic mouse model

BackgroundSleep is an essential process that supports brain health and cognitive function in part through the modification of neuronal synapses. Sleep disruption, and impaired synaptic processes, are common features in neurodegenerative diseases, including Alzheimers disease (AD). However, the casual role of sleep disruption in disease progression is not clear. Neurofibrillary tangles, made from hyperphosphorylated and aggregated Tau protein, form one of the major hallmark pathologies seen in AD and contribute to cognitive decline, synapse loss and neuronal death. Tau has been shown to aggregate in synapses which may impair restorative synapse processes occurring during sleep. However, it remains unclear how sleep disruption and synaptic Tau pathology interact to drive cognitive decline. It is also unclear whether the sexes show differential vulnerability to the effects of sleep loss in the context of neurodegeneration. MethodsWe used a piezoelectric home-cage monitoring system to measure sleep behavior in 3-11month-old transgenic hTau P301S Tauopathy model mice (PS19) and littermate controls of both sexes. Subcellular fractionation and Western blot was used to examine Tau pathology in mouse forebrain synapse fractions. To examine the role of sleep disruption in disease progression, mice were exposed to acute or chronic sleep disruption. The Morris water maze test was used to measure spatial learning and memory performance. ResultsPS19 mice exhibited a selective loss of sleep during the dark phase, referred to as hyperarousal, as an early symptom with an onset of 3months in females and 6months in males. At 6months, forebrain synaptic Tau burden did not correlate with sleep measures and was not affected by acute or chronic sleep disruption. Chronic sleep disruption accelerated the onset of decline of hippocampal spatial memory in PS19 males, but not females. ConclusionsDark phase hyperarousal is an early symptom in PS19 mice that precedes robust Tau aggregation. We find no evidence that sleep disruption is a direct driver of Tau pathology in the forebrain synapse. However, sleep disruption synergized with Tau pathology to accelerate the onset of cognitive decline in males. Despite the finding that hyperarousal appears earlier in females, female cognition was resilient to the effects of sleep disruption.

neuroscience↗

bioRxiv2022

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD. HighlightsO_LIMorphine withdrawal differentially dysregulates the sleep of male and female mice C_LIO_LI3-day precipitated withdrawal results in larger changes than spontaneous withdrawal C_LIO_LIOpioid withdrawal affects responses to future sleep deprivation differently between sexes C_LI

neuroscience↗

bioRxiv2021

Early life sleep disruption drives lasting sex-specific changes in behavior in genetically vulnerable Shank3 heterozygous autism model mice

BackgroundPatients with autism spectrum disorder (ASD) experience high rates of sleep disruption beginning early in life, however the developmental consequences of this disruption are not understood. We examined sleep behavior and the consequences of sleep disruption in developing mice bearing C-terminal truncation mutation in the high-confidence ASD risk gene SHANK3 (Shank3{Delta}C). We hypothesized that sleep disruption may be an early sign of developmental divergence, and that clinically-relevant Shank3WT/{Delta}C mice may be at increased risk of lasting deleterious outcomes following early-life sleep disruption. MethodsWe recorded sleep behavior in developing Shank3{Delta}C/{Delta}C, Shank3WT/{Delta}C, and wild type siblings of both sexes using a non-invasive home cage monitoring system. Separately, litters of Shank3WT/{Delta}C and wildtype littermates were exposed to automated mechanical sleep disruption for 7 days prior to weaning (early-life sleep disruption: ELSD) or post-adolescence (PASD) or undisturbed control (CON) conditions. All groups underwent standard behavioral testing as adults. ResultsMale and female Shank3{Delta}C/{Delta}C mice slept significantly less than wild type and Shank3WT/{Delta}C siblings shortly after weaning, with increasing sleep fragmentation in adolescence, indicating that sleep disruption has a developmental onset in this ASD model. ELSD treatment interacted with genetic vulnerability in Shank3WT/{Delta}Cmice, resulting in lasting, sex-specific changes in behavior, whereas wildtype siblings were largely resilient to these effects. Male ELSD Shank3WT/{Delta}Csubjects demonstrated significant changes in sociability, sensory processing, and locomotion, while female ELSD Shank3WT/{Delta}C subjects had a significant reduction in risk aversion. CON Shank3WT/{Delta}C mice, PASD mice, and all wildtype mice demonstrated typical behavioral responses in most tests. LimitationsThis study tested the interaction between developmental sleep disruption and genetic vulnerability using a single ASD mouse model: Shank3{Delta}C (deletion of exon 21). The broader implications of this work should be supported by additional studies using ASD model mice with distinct genetic vulnerabilities. ConclusionOur study shows that sleep disruption during sensitive periods of early life interact with underlying genetic vulnerability to drive lasting and sex-specific changes in behavior. As individuals progress through maturation they gain resilience to the lasting effects of sleep disruption. This work highlights developmental sleep disruption as an important vulnerability in ASD susceptibility.

animal behavior and cognition↗

bioRxiv2021

Coordinated regulation of CB1 cannabinoid receptors and anandamide metabolism stabilize network activity during homeostatic scaling down

Neurons express overlapping homeostatic mechanisms to regulate synaptic function and network properties in response to perturbations of neuronal activity. Endocannabinoids (eCBs) are bioactive lipids synthesized in the post-synaptic compartments to regulate synaptic transmission, plasticity, and neuronal excitability primarily through retrograde activation of pre- synaptic cannabinoid receptor type 1 (CB1). The eCB system is well-situated to regulate neuronal network properties and coordinate pre- and post-synaptic activity. However, the role of the eCB system in homeostatic adaptations to neuronal hyperactivity is unknown. To address this issue, we used western blot and targeted lipidomics to measure adaptations in eCB system to bicuculline (BCC)-induced chronic hyperexcitation in mature (>DIV21) cultured rat cortical neurons, and used multielectrode array recording and live-cell imaging of glutamate dynamics to test the effects of pharmacological manipulations of eCB on network activities. We show that BCC-induced chronic hyperexcitation triggers homeostatic downscaling and a coordinated adaptation to enhance tonic eCB signaling. Hyperexcitation triggers first the downregulation of fatty acid amide hydrolase (FAAH), the lipase that degrades the eCB anandamide, then an accumulation of anandamide and related metabolites, and finally a delayed upregulation of surface and total CB1. Additionally, we show that BCC-induced downregulation of surface AMPA-type glutamate receptors (AMPARs) and upregulation of CB1 occur through independent mechanisms. Finally, we show that endocannabinoids support baseline network activities before and after downscaling and is engaged to suppress network activities during adaptation to hyperexcitation. We discuss the implications of our findings in the context of downscaling and homeostatic regulation of oscillatory network activities. Significance statementNeurons are remarkably resilient to perturbations in network activities thanks to the expression of overlapping homeostatic adaptations. In response to network hyperactivity or silencing, neurons respond through regulating excitatory and inhibitory post-synaptic neurotransmitter receptors density, probability of pre-synaptic neurotransmitter release, and/or membrane excitability. The endocannabinoid system is a prominent signaling pathway at many synapses that is known to be involved in multiple forms of short- and long-term synaptic plasticity. Here we find that components of the endocannabinoid system are upregulated in response to chronic hyperexcitation of cultured cortical neurons, and that endocannabinoid signaling is required to maintain network activity but also suppresses network events during hyperexcitation. This work supports a novel tonic homeostatic function for the endocannabinoid system in neurons.

neuroscience↗

bioRxiv2021

Tonic endocannabinoid signaling supports sleep through development in both sexes.

Sleep is an essential behavior that supports brain function and cognition throughout life, in part by acting on neuronal synapses. The synaptic signaling pathways that mediate the restorative benefits of sleep are not fully understood, particularly in the context of development. Endocannabinoids (eCBs) including 2-arachidonyl glycerol (2-AG) and anandamide (AEA), are bioactive lipids that activate cannabinoid receptor, CB1, to regulate synaptic transmission and mediate cognitive functions and many behaviors, including sleep. We used targeted mass spectrometry to measure changes in forebrain synaptic eCBs during the sleep/wake cycle in developing and adult mice. We find that eCBs are downregulated in response to acute sleep deprivation in juvenile mice, while in young adults eCBs are upregulated during the sleep phase in a circadian manner. Next we manipulated the eCB system using selective pharmacology and measured the effects on sleep behavior in developing and adult mice of both sexes using a non-invasive piezoelectric home-cage recording apparatus. Enhancement of eCB signaling through inhibition of 2-AG or AEA degradation, increased dark phase sleep amount and bout length in developing and adult males, but not in females. Inhibition of CB1 by injection of the antagonist AM251 reduced sleep time and caused sleep fragmentation in developing and adult males and females. Our data suggest that males are more sensitive to the sleep promoting effects of enhanced eCBs but that tonic eCB signaling supports sleep behavior through multiple stages of development in both sexes. This work informs the further development of cannabinoid-based therapeutics for sleep disruption.

animal behavior and cognition↗