1998 — 2000 |
Wisor, Jonathan P |
F32Activity Code Description: To provide postdoctoral research training to individuals to broaden their scientific background and extend their potential for research in specified health-related areas. |
Dopamine &Sleep Homeostasis--Molecular Genetic Approach
The Compensatory Sleep Response (CSR; characterized by increased sleep time and depth) that is seen in mice after a period of total sleep deprivation (TSD) indicates that sleep is a homeostatic process. The mechanism for this homeostatic drive is unknown, but is likely to be involved in the etiology of some sleep disorders. We have found that similar to TSD, methamphetamine, an inhibitor of the cell membrane dopamine (DA) transporter (DAT) and of the intracellular DA transporter (VMAT2), produces sleep loss followed by a CSR in mice. In contrast the DAT-specific inhibitor GBRI2909 produces sleep loss without a subsequent CSR. In light of these observations we theorize that intracellular DA stores play a critical role in sleep homeostasis. This proposal addresses three issues relevant to this theory. Is the wake promoting effect GBR12909 mediated exclusively through inhibition of DAT9? Are the wake promoting effect of methamphetamine and the subsequent CSR mediated through inhibition of DAT and of intracellular DA stores? Do genetic alterations of cell membrane (DAT) and vesicular (VMAT2) DA transporters alter CSR to TSD? We propose a targeted molecular genetic approach to address these questions. To determine the molecular sites of action of GBRI2909 and methamphetamine, we will study the effects of these drugs on sleep in mice with genetic alterations of DAT and VMAT2 expression. To determine the role of DAT and VMAT2 in physiological sleep in the absence of pharmacological manipulation, we will also study the CSR to TSD in these genetically engineered mice.
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0.913 |
2010 |
Wisor, Jonathan P |
R15Activity Code Description: Supports small-scale research projects at educational institutions that provide baccalaureate or advanced degrees for a significant number of the Nation’s research scientists but that have not been major recipients of NIH support. The goals of the program are to (1) support meritorious research, (2) expose students to research, and (3) strengthen the research environment of the institution. Awards provide limited Direct Costs, plus applicable F&A costs, for periods not to exceed 36 months. This activity code uses multi-year funding authority; however, OER approval is NOT needed prior to an IC using this activity code. |
An Essential Role For Corticothalamic Slow Waves in Sleep Regulation @ Washington State University
DESCRIPTION (provided by applicant): Poor-quality sleep and sleep insufficiency are significant risk factors for physical and mental illness and are, thus, of major public-health concern. Obesity, diabetes and cardiovascular disease are all statistically linked to sleep insufficiency generally and to the disruption of the portion of sleep characterized by slow electroencephalographic (EEG) oscillations ("slow wave sleep";SWS), specifically. In addition, sleep insufficiency induces neurobehavioral deficits, many of which can be attributed to disruption of SWS. The negative consequences of SWS disruption mandate for additional research on the mechanisms and consequences of slow waves in the sleep EEG. Much work to date has focused on the roles of subcortical neuromodulatory influences and thalamic cell physiology in regulating slow waves. However, the degree to which the electrophysiological oscillations intrinsic to neurons of the cerebral cortex regulate EEG slow wave timing, frequency and amplitude re- mains uncertain. Thus, there is a critical unmet need for further studies on the neurobiological underpinnings of the restorative effects of slow waves. Here, we propose a unique approach that will utilize optogenetic stimulation of cortical pyramidal neurons to manipulate cortical rhythms and measure the effect of this manipulation on slow wave activity. The central hypothesis to be addressed is that slow oscillations (<4 Hz) in the activity of pyramidal neurons are necessary for both the discharge of sleep need and macromolecular changes during sleep. In the proposed experiments, we will test the hypothesis that regular rhythmic activation of pyramidal neurons in the cerebral cortex increases subsequent slow wave activity in the cerebral cortex. We will test the hypothesis that the discharge of excessive sleep need subsequent to SD, as measured by a decline in EEG slow wave activity across time, and the macromolecular response to SD require uninterrupted slow wave activity in the cerebral cortex. The proposed experiments have the potential to identify a novel mechanism by which a cell population within the cerebral cortex regulates EEG slow wave production and sleep need. These experiments, using techniques that the principal investigator has taught to a number of trainees in the past, will meet an unmet need for research opportunities for WSU Spokane's student population in the biomedical sciences. Finally, these experiments will provide data that validate our techniques as a novel way of studying slow wave sleep function, and in so doing, will place us in a strong position to seek expanded NIH funding at the R01 level. PUBLIC HEALTH RELEVANCE: Insufficient sleep has a number of negative effects on health and well-being. We seek to increase our understanding of the causes and consequences of insufficient sleep at the cellular and biochemical levels. We propose to determine whether a class of cells known as pyramidal cells in the cerebral cortex of the brain, serve an essential function in the brain's response to sleep insufficiency. We do so with the anticipation that these studies will lead to potential countermeasures for the health effects of insufficient sleep.
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0.958 |
2012 — 2015 |
Wisor, Jonathan P |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Regulatory Relationship of Glucose Metabolism and Cerebral Slow Wave Activity @ Washington State University
DESCRIPTION (provided by applicant): Poor-quality sleep and sleep insufficiency are significant risk factors for physical and mental illness and are of major public-health concern. Much effort to date has rightfully focused on the roles of subcortical populations of neurons in the regulation of biochemical and electroencephalographic responses to sleep insufficiency. Despite the body of evidence that sleep is regulated locally within functional circuits of the cerebral cortex, there is a relative paucity of experimental data on the regulation of sleep by mechanisms intrinsic to the cerebral cortex. The objective of this proposal is to determine the extent to which glycolytic metabolism within the cerebral cortex regulates electroencephalographic slow wave activity during sleep. The central hypothesis is that the temporal dynamics of slow wave activity during non-rapid eye movement sleep are regulated in a feedback relationship between slow wave activity and the glucose metabolite, lactate in the cerebral cortex. The rationale for the research proposed here is that documentation of a feedback relationship between lactate concentration and slow wave activity in the electroencephalogram will improve our understanding of the cerebral effects of sleep insufficiency and will identify the regulation of cerebral glucose utilization as a function of slep slow waves. The working hypothesis for the proposed experiments is that accumulation of lactate in the cerebral cortex during wakefulness promotes slow wave activity during subsequent sleep and slow wave activity during sleep, in turn, promotes a decline in lactate levels. We propose four specific aims designed to document this relationship. The first aim is to determine the extent to which genetic differences in the temporal dynamics of sleep slow wave activity are paralleled by genetic differences in the sleep state-dependent dynamics of lactate in the cerebral cortex. The second aim is to determine whether excessive activation of discrete functional units in the cerebral cortex, a manipulation that increases slow wave activity during subsequent sleep, also increases the rate of lactate accumulation in the cerebral cortex. The third aim is to determine whether manipulations of slow wave activity in the cerebral cortex alter lactate levels independently of sleep state. The final aim is to determine whether the processing of lactate as a glycolytic fuel by the cerebral cortex modulates sleep slow wave activity. The proposed experiments are innovative, in our opinion, because they have the potential to identify a novel regulatory relationship between sleep and cerebral glucose metabolism. The results are expected to collectively establish that sleep slow wave activity serves to release the lactate accumulated in the cerebral cortex during wakefulness. The experiments may yield novel insights into the etiology of sleep disorders and may yield novel tools for intervention in disorders of cerebral metabolism. PUBLIC HEALTH RELEVANCE: Insufficient sleep has a number of negative effects on health and well-being. We seek to increase our understanding of the causes and consequences of insufficient sleep at the physiological and biochemical levels. Slow waves in the electrical activity of neurons in the cerebral cortex are a defining feature of non-rapid eye movement sleep and are likely to mediate at least some of the restorative, health-promoting consequences of sleep. The goal of our research is to increase our understanding of the relationship between sleep slow waves and sleep-related changes in cerebral glucose metabolism. With this goal in mind, we propose a series of experiments in which we will determine the extent to which the temporal dynamics of slow wave activity are related to changes in the concentration of the glucose metabolite, lactate, in the cerebral cortex. We will do so with the anticipation that these studies will lead to potential countermeasures for the health effects of insufficient sleep.
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0.958 |
2013 — 2014 |
Wisor, Jonathan P |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Optogenetic Resource For Studying Cerebral Cortex Network Function @ Washington State University
DESCRIPTION (provided by applicant): The cerebral cortex is a complex network of neurochemically-defined subpopulations of cells. Understanding how distinct neural populations interact to generate the dynamic electrophysiological oscillations that characterize the cerebral cortical network during wake and sleep is a pressing challenge to the field of neuroscience. There is a critical unmet need for novel experimental resources to address hypotheses in this context. We have developed a novel transgenic mouse line (NPY-ChR2- eYFP) in which the neuropeptide Y (NPY) promoter drives expression of the light-sensitive cation channel Channelrhodopsin2 (ChR2) and the marker protein enhanced yellow fluorescent protein (eYFP). A subpopulation of Npy-positive cells in the cerebral cortex (sleep-active neurons; SANs) is a putative regulator of sleep-dependent changes in cerebral cortex network slow wave activity, plasticity and blood flow. Our preliminary data demonstrate that the transgene is expressed in the brain, and that optogenetic manipulation of the cerebral cortex triggers an increase in slow activity in the electroencephalogram of transgene-expressing mice. These data demonstrate that an optogenetic strategy to manipulate cerebral cortical neuronal network properties in these animals is feasible. The overarching goal of this work is to develop a set of protocols in which NPY-ChR2-eYFP mice can be used to delineate the functions of the cerebral cortical NPY-expressing interneuron population generally, and the SAN population specifically, in generating cerebral cortical electrophysiological events. We will achieve this goal by pursuing two aims. In Aim 1, we will use immunohistochemistry to verify that the NPY-ChR2-eYFP construct targets transgene expression to NPY-positive cells and SANs in the cerebral cortex. In Aim 2, we will optimize optogenetic stimulation protocols for manipulating the activity of the target cell population in vivo. Collectively, these studies will yield a set of protocols to advance our knowledge of the function of the NPY-positive population in regulating cortical electrophysiological oscillations. Additionally, the transgenic mouse line and protocols for experimentation on this line will become a public resource applicable in other areas of research such as neurovascular coupling, neural regulation of stress responses and feeding, and the pathophysiology of stroke.
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0.958 |
2014 — 2015 |
Wisor, Jonathan P |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Chronic Methamphetamine Disrupts Sleep-Dependent Molecular/Energetic Homeostasis @ Washington State University
DESCRIPTION (provided by applicant): The negative effects of methamphetamine abuse and addiction on psychological and physical well-being are a major public health concern. Much effort to date has rightfully focused on the role of the brain's reward circuitry in mediating the behavioral and psychological effects of methamphetamine. While such studies have led to important insights into the mechanisms of methamphetamine addiction, the rate of relapse among abstinent methamphetamine abusers remains high. Hypersomnolence, characterized by excessive daytime sleepiness, is typical of early abstinent methamphetamine users. In normal individuals sleep is coupled to reduced cerebral glucose metabolism. In early abstinent methamphetamine users, hypersomnolence is paralleled by excessive glucose utilization in the brain. The neurobiological mechanism whereby methamphetamine alters sleep and cerebral metabolism is unknown. We posit that the previously documented suppression of a synaptic connectivity-related gene network in the brain (including the transcriptional regulator Egr3 and its target, the activity-regulated cytoskeleton-associated protein, Arc) by methamphetamine disrupts the neuroenergetic function of sleep. Our overarching hypothesis is that disruption of the sleep/wake- dependent dynamics of Egr3 and Arc expression by methamphetamine prevents sleep-dependent changes in glucose metabolism and electroencephalographic slow wave dynamics. Experimentation on Egr3-deficient mice, in which Arc expression is suppressed in a manner similar to chronic methamphetamine exposure, will allow us to address our working hypothesis for the proposed experiments: sleep/wake cycle-dependent dynamics of the Egr3/Arc transcriptional regulatory pathway is essential for the decline of cerebral glucose metabolism and sleep slow wave activity that define normal sleep/wake cycles. We propose two specific aims in which we will determine whether Egr3-deficiency modifies 1) sleep/wake cycle-dependent changes in sleep slow wave activity and cerebral glucose metabolism and 2) METH-induced suppression of sleep/wake cycle- dependent Arc expression. The anticipated results will establish a conceptual and experimental framework for future work by demonstrating a mechanistic link between changes in Egr3/Arc expression and sleep- dependent metabolic events. The proposed experiments are innovative, in our opinion, because they have the potential to identify a previously unrecognized impact of methamphetamine abuse on a fundamental brain function. The results are expected to collectively establish that chronic methamphetamine exposure disrupts the neuroenergetic function of sleep.
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0.958 |
2018 — 2021 |
Wisor, Jonathan P |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Sleep Deprivation Elevates, and Sleep Alleviates, Oxidative Stress in the Brain. @ Washington State University
Abstract For reasons that remain unknown, sleep is essential for the reversal of deficits in cognition and performance that accumulate with increased severity during protracted wake. One of the most robust and reliable features of sleep is a reduction of cerebral metabolism, manifested by a decline in brain temperature and a decline in brain glucose and oxygen utilization, relative to wake. It stands to reason that the metabolic down state is essential for the restorative function of sleep, yet the biochemical basis for this relationship is uncertain. Oxidative metabolism of glucose fuels neuronal activity. Postmortem assays indicate that protracted wake produces an accumulation of oxidative stress in the brain. We hypothesize that reduced glucose utilization in sleep reverses a metabolically-driven shift in the redox status (the balance of oxidation and reduction reactions) of parvalbumin-positive neurons caused by the high metabolic demand of these cells in the waking brain. We further hypothesize that this function of sleep is facilitated in part by an extracellular matrix structure known as perineuronal nets, which serve to buffer against oxidative stress in metabolically vulnerable neurons. To address these hypotheses, we will perform a systemic pharmacological manipulations (the oxidation/reduction reaction substrate nicotinic adenine dinucleotide) known to affect the brain?s capacity to withstand oxidative stress. We will also assess perform brain region-specific depletion of perineuronal nets. We will assess the effects of these manipulations, and those of sleep/wake cycle manipulations, on cellular redox status markers, both in real- time in vivo using intravital microscopy, and post mortem by coupling oxidation assays with cell type-specific immunochemical markers and histochemical assessment of perineuronal net intensity. We will additionally measure the effects of the experimental manipulations on electroencephalographic markers for brain fatigue and sleep need. The anticipated results will establish a causal interrelationship between sleep/wake cycles and brain redox status, and will identify brain oxidation/reduction reactions as a target for both diagnostic inquiry and therapeutic intervention in the face of sleep insufficiency. 1
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0.958 |