Publications by authors named "Mahesh M Thakkar"

Sleep disturbances, including insomnia and excessive daytime sleepiness, are highly prevalent in patients with ischemic stroke (IS), which severely impacts recovery and rehabilitation efforts. However, how IS induces sleep disturbances is unclear. Three experiments were performed on middle-aged C57BL/6J mice, instrumented with sleep recording electrodes and/or subjected to 1 h of middle cerebral artery (MCAO; Stroke group) or sham (Sham group) occlusion to induce IS.

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Characterizing the spatial relationship between blood vessel and lymphatic vascular structures, in the mice dura mater tissue, is useful for modeling fluid flows and changes in dynamics in various disease processes. We propose a new deep learning-based approach to fuse a set of multi-channel single-focus microscopy images within each volumetric z-stack into a single fused image that accurately captures as much of the vascular structures as possible. The red spectral channel captures small blood vessels and the green fluorescence channel images lymphatics structures in the intact dura mater attached to bone.

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Post-traumatic stress disorder (PTSD) is a debilitating neuropsychiatric illness affecting > 7 million people every year in the US. Recently, we have shown that the mouse model of predator odor trauma (POT) displayed contextual conditioning and core features of PTSD including sleep disturbances (hyperarousal) and retrieval of traumatic memories following exposure to objective reminders (re-experiencing). PTSD is a disorder of memory function.

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Introduction: Alcohol use disorder (AUD), a chronic brain disorder, is characterized by a multitude of symptoms, including insomnia, during withdrawal. Previously, we have shown that rats exposed to chronic alcohol displayed insomnia-like symptoms during acute withdrawal. Since insomnia lasts for several years and is a major risk factor of relapse to alcoholism, the present study is designed to investigate the long-term effects of alcohol withdrawal on sleep-wakefulness.

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Alcohol use disorders (AUD) are chronic relapsing brain disorder characterized by compulsive and heavy alcohol consumption. During acute withdrawal, patients with AUD display excessive daytime sleepiness, a condition linked to serious life-threatening complications, however, the mechanism is not known. Orexin and melanin-concentrating hormone (MCH) are the two hypothalamic neuropeptides that regulate many behaviors including sleep-wakefulness, and alcohol consumption, reinforcement, and reinstatement.

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Background: Alcohol use disorder (AUD) develops after chronic and heavy use of alcohol. Insomnia, a hallmark of AUD, plays a crucial role in the development of AUD. However, the causal mechanisms are unknown.

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Permanently stored memories become labile through a process called reactivation. Once reactivated, these memories need reconsolidation to become permanent. Sleep is critical for memory consolidation.

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Restless Legs Syndrome is a highly prevalent sensorimotor disorder characterized by urge to move the legs due to discomfort that primarily happens in the evening or at nights. Although the exact pathophysiology remains unclear, brain iron deficiency and altered dopaminergic function appears to play an important role in the pathogenesis of this condition. This disorder affects women more frequently and is associated with significant morbidity.

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Parasomnias are abnormal and undesirable behaviors during sleep and are thought to be due to the sleep state instability. Some of them are benign, while some of them point to a possible underlying neurodegenerative process. This article briefly discusses the clinical characteristics, demographics, and pathophysiology of major parasomnias and associated disorders.

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Binge alcohol drinking, a risky pattern of alcohol consumption, has severe consequences toward health and well-being of an individual, his family, and society. Although, binge drinking has detrimental effects on sleep, underlying mechanisms are unknown. We used adult male C57BL/6J mice and exposed them to a single, 4-h session of binge alcohol self-administration, in stress-free environment, to examine neuronal mechanisms affecting sleep.

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Melatonin promotes sleep. However, the underlying mechanisms are unknown. Orexin neurons in the perifornical lateral hypothalamus (PFH) are pivotal for wake promotion.

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Increasing evidences suggest that the predator threat model is a valid animal model of post-traumatic stress disorder (PTSD). However, sleep has never been examined in this model. Since sleep disturbances, including insomnia and excessive daytime sleepiness, are severe and protracted symptoms of PTSD, we hypothesized that mice exposed to predator odor trauma (POT) will display contextual fear conditioning along with severe and protracted sleep disruptions.

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Alcohol has a profound effect on sleep. However, neuronal substrates mediating sleep-promoting effects of alcohol are unknown. Since the basal forebrain (BF) cholinergic neurons are implicated in the homeostatic regulation of sleep, we hypothesized that the BF cholinergic neurons may have an important role in sleepiness observed after alcohol consumption.

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Investigative research into curative treatments for dysphagia is hindered by our incomplete understanding of the neural mechanisms of swallowing in health and disease. Development of translational research models is essential to bridge this knowledge gap by fostering innovative methodology. Toward this goal, our laboratory has developed a translational research assessment tool to investigate the neural mechanistic control of swallowing in unrestrained, self-feeding mice.

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The present study explored the role of the amygdala in mediating a unique pattern of feeding behavior driven by intra-accumbens (intra-Acb) opioid activation in the rat. Temporary inactivation of the basolateral amygdala (BLA), via GABAA agonist muscimol administration prevents increased consumption following intra-Acb opioid administration of the selective μ-opioid agonist D-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO), yet leaves food approach behaviors intact, particularly after consumption has ended. One interpretation is that inactivation of the BLA selectively blocks neural activity underlying DAMGO-driven consummatory (consumption) but not appetitive (approach) behaviors.

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Nicotine and alcohol co-abuse is highly prevalent, although the underlying causes are unclear. It has been suggested that nicotine enhances pleasurable effects of alcohol while reducing aversive effects. Recently, we reported that nicotine acts via the basal forebrain (BF) to activate nucleus accumbens and increase alcohol consumption.

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Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half.

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Background: Nicotine and alcohol co-abuse is highly prevalent. Recently, we have shown that nicotine infusion in the basal forebrain (BF) increases alcohol consumption. As nucleus accumbens (NAc) is the terminal brain region associated with drug addiction, we hypothesize that nicotine infusion in the BF may enhance alcohol-induced activation of NAc.

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Background: Binge alcohol drinking is among the most common pattern of alcohol consumption in our society. Binge alcohol consumption has serious negative consequence on mental and physical health. Although alcohol consumption is known to have profound impact on sleep, it is yet unknown as to how binge alcohol affects/alters sleep-wakefulness.

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Study Objectives: Alcohol tolerance is a major contributor towards the development of alcohol dependence. Does alcohol intake result in rapid tolerance development to alcohol induced NREM sleep promotion? This has never been examined. Our objective was to examine whether two bouts of alcohol consumption on consecutive days results in rapid tolerance development to alcohol-induced NREM sleep promotion.

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Study Objectives: Strong clinical and preclinical evidence suggests that acute ethanol promotes sleep. However, very little is known about how and where ethanol acts to promote sleep. We hypothesized that ethanol may induce sleep by increasing extracellular levels of adenosine and inhibiting orexin neurons in the perifornical hypothalamus.

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Background: Alcohol and nicotine are the most commonly abused drugs. The frequent co-morbidity of alcohol and nicotine addiction has led to the hypothesis that they may act via a common substrate: the nicotinic acetylcholine receptors (nAChRs) especially α4β2 and α7 subtypes, the most prevalent nAChRs in the brain. Compelling evidence suggests that alcohol enhances the function of α4β2 subtype.

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Recent studies have demonstrated that the function of glia is not restricted to the support of neuronal function. Especially, astrocytes are essential for neuronal activity in the brain. Astrocytes actively participate in synapse formation and brain information processing by releasing or uptaking gliotransmitters such as glutamate, d-serine, adenosine 5'-triphosphate (ATP), and adenosine.

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In the central nervous system, adenosine and adenosine 5'-triphosphate (ATP) play an important role in regulating neuronal activity as well as controlling other neurotransmitter systems, such as, GABA, glutamate, and dopamine. Ethanol increases extracellular adenosine levels that regulate the ataxic and hypnotic/sedative effects of ethanol. Interestingly, ethanol is known to increase adenosine levels by inhibiting an ethanol-sensitive adenosine transporter, equilibrative nucleoside transporter type 1 (ENT1).

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The locus coeruleus (LC) regulates sleep/wakefulness and is densely innervated by orexinergic neurons in the lateral hypothalamus. Here we used small interfering RNAs (siRNAs) to test the role of LC orexin type 1 receptor (OxR1) in sleep–wake control. In sleep studies, bilateral OxR1 siRNA injections led to an increase of time spent in rapid eye movement (REM) sleep, which was selective for the dark (active) period, peaked at approximately 30% of control during the second dark period after injection and then disappeared after 4 days.

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