Publications by authors named "Matthew Lopez"

Reorientation, the process of regaining one's bearings after becoming lost, requires identification of a spatial context (context recognition) and recovery of facing direction within that context (heading retrieval). We previously showed that these processes rely on the use of features and geometry, respectively. Here, we examine reorientation behavior in a task that creates contextual ambiguity over a long timescale to demonstrate that male mice learn to combine both featural and geometric cues to recover heading.

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Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system (CNS). Most GABAergic neurons synthesize GABA from glutamate and release it in the synaptic cleft in the CNS. However, astrocytes can also synthesize and release GABA, activating GABA receptors in the neighboring neurons in physiological and pathological conditions.

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Human aging is associated with senescence of the hypothalamic-pituitary-adrenal (HPA) axis, leading to progressive dysregulation characterized by increased cortisol exposure. This key hormone is implicated in the pathogenesis of many age-related diseases. Common marmosets (Callithrix jacchus) display a wide spectrum of naturally occurring age-related pathologies that compare similarly to humans and are increasingly used as translational models of aging and age-related disease.

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The common marmoset (Callithrix jacchus), a small South American monkey, is an important nonhuman primate model in the study of aging and age-related neurodegenerative disease, including Alzheimer's disease, Parkinson's disease, and related dementias. Thorough characterization of the wild type marmoset brain agingmodel, including biomarkers of aging and neural degeneration, will further the marmoset's utility in translational research. We measured serum concentration of four key biomarkers of neural degeneration [total tau (T-tau), glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), and ubiquitin C-terminal hydrolase-L1 (UCH-L1)] via single molecule array from 24 marmosets (female n = 13, male n = 11) ranging in age from 1.

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Reorientation, the process of regaining one's bearings after becoming lost, requires identification of a spatial context (context recognition) and recovery of heading direction within that context (heading retrieval). We previously showed that these processes rely on the use of features and geometry, respectively. Here, we examine reorientation behavior in a task that creates contextual ambiguity over a long timescale to demonstrate that mice learn to combine both featural and geometric cues to recover heading with experience.

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We conducted a dose-response study of dexamethasone to investigate an optimal dexamethasone suppression test for common marmosets. Twelve marmosets received 0.1, 0.

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Reorientation enables navigators to regain their bearings after becoming lost. Disoriented individuals primarily reorient themselves using the geometry of a layout, even when other informative cues, such as landmarks, are present. Yet the specific strategies that animals use to determine geometry are unclear.

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Temporal costs influence reward-based decisions. This is commonly studied in temporal discounting tasks that involve choosing between cues signaling an imminent reward option or a delayed reward option. However, it is unclear whether the temporal delay before a reward can alter the value of that option.

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Poor sleep quality is associated with age-related cognitive decline, and whether reversal of these alterations is possible is unknown. In this study, we report how sleep deprivation (SD) affects hippocampal representations, sleep patterns, and memory in young and old mice. After training in a hippocampus-dependent object-place recognition (OPR) task, control animals sleep ad libitum, although experimental animals undergo 5 h of SD, followed by recovery sleep.

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Background And Purpose: Differentiating between cervical nerve root and peripheral nerve injuries can be challenging. A phenomenon known as double crush syndrome may increase the susceptibility to injury and symptoms at other locations along the course of the nerve. The purpose of this case report is to describe the physical therapy differential diagnosis and management of a cyclist with upper extremity pain, weakness, and paresthesia.

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Restoration of the joint line of the knee during primary and revision total knee arthroplasty is a step that directly influences patient outcomes. In revision total knee arthroplasty, necessary bony landmarks may be missing or obscured, so there remains a lack of consensus on how to accurately identify and restore the joint line of the knee. In this study, 50 magnetic resonance images of normal knees were analyzed to determine a quantitative relationship between the joint line of the knee and 6 bony landmarks: medial and lateral femoral epicondyles, medial and lateral femoral metaphyseal flares, tibial tubercle, and proximal tibio-fibular joint.

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EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Identify at-risk populations for giant cell tumor of bone. 2.

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Introduction: Enteric duplications are rare congenital anomalies of the digestive tract that can occur anywhere along its length, with the majority being found in the small intestine. The duodenum is the least common site. Almost all symptomatic duodenal duplications present early in life with abdominal pain and pancreatitis.

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Background: Methicillin-resistant Staphylococcus aureus infections are a well-documented risk of surgery and are becoming increasingly difficult to treat owing to continued acquired resistance. A new antibiotic for treatment of Staphylococcus aureus is telavancin.

Case Description: A patient at our institution was prescribed telavancin for multiple spinal abscesses before spinal surgery.

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Background: Ablation of TRPV1-expressing nociceptive fibers with the potent capsaicin analog resiniferatoxin (RTX) results in long lasting pain relief. RTX is particularly adaptable to focal application, and the induced chemical axonopathy leads to analgesia with a duration that is influenced by dose, route of administration, and the rate of fiber regeneration. TRPV1 is expressed in a subpopulation of unmyelinated C- and lightly myelinated Adelta fibers that detect changes in skin temperature at low and high rates of noxious heating, respectively.

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