Faculty Bibliography

1-octanol is a therapeutic candidate for disorders involving the abnormal activation of the T-type calcium current since it blocks this current specifically. Such disorders include essential tremor and a group of neurological and psychiatric disorders resulting from thalamocortical dysrhythmia (TCD). For example, clinically, the observable phenotype in essential tremor is the tremor itself. The differential diagnostic of TCD is not based only on clinical signs and symptoms. Rather, TCD incorporates an electromagnetic biomarker, the presence of abnormal thalamocortical low frequency brain oscillations. The effect of 1-octanol on brain activity has not been tested. As a preliminary step to such a TCD study, we examined the short-term effects of a single dose of 1-octanol on resting brain activity in 32 healthy adults using magnetoencephalograpy. Visual inspection of baseline power spectra revealed that the subjects fell into those with strong low frequency activity (set 2, n = 11) and those without such activity, but dominated by an alpha peak (set 1, n = 22). Cross-validated linear discriminant analysis, using mean spectral density (MSD) in nine frequency bands as predictors, found overall that 82.5% of the subjects were classified as determined by visual inspection. The effect of 1-octanol on the MSD in narrow frequency bands differed between the two subject groups. In set 1 subjects the MSD increased in the 4.5-6.5Hz and 6.5-8.5 Hz bands. This was consistent with a widening of the alpha peak toward lower frequencies. In the set two subjects the MSD decrease in the 2.5-4.5 Hz and 4.5-6.5 Hz bands. This decreased power is consistent with the blocking effect of 1-octanol on T-type calcium channels. The subjects reported no adverse effects of the 1-octanol. Since stronger low frequency activity is characteristic of patients with TCD, 1-octanol and other T-type calcium channel blockers are good candidates for treatment of this group of disorders following a placebo-controlled study.

Introduction Radiation Therapy (RT) for Head and Neck Cancer (HNC) can cause significant oral complications. However, modern techniques such as Intensity Modulated RT (IMRT) may reduce their incidence/severity. Objectives To assess severity of oral complications 6 months after modern RT for HNC. Methods OraRad is an ongoing 6-center prospective cohort study. Oral outcomes are evaluated before start of RT (baseline), and 6, 12, 18, 24 months after RT. For this analysis, we compared baseline vs. 6 month data using mixed linear models for continuous measures and generalized estimating equations for categorical measures. Data are presented as outcome mean (SD, number of subjects), unless otherwise stated. Results Stimulated whole salivary flow declined from 1.09 ml/min (0.67, 354) at baseline to 0.47 (0.47, 216) at 6 months (p < 0.0001). Maximal mouth opening reduced from 45.58 mm (10.40, 371) to 42.53 (9.52, 208) (p < 0.0001). 17 of 203 subjects (8.4%) had persistent oral mucositis at 6 months. Overall oral health-related quality of life score (1-4 scale) worsened from 1.48 (0.42, 371) to 1.86 (0.47, 211) (p < 0.0001). Contributing to this decline were subject-reported negative changes related to swallowing solid food, choking when swallowing, opening the mouth wide, dry mouth, sticky saliva, smell, and taste (p < 0.0001). At 6 months, there was greater frequency of using dental floss, and greater proportion using supplemental fluoride (p < 0.0001). Conclusions Despite use of IMRT, HNC patients continue to suffer significant oral complications of cancer therapy, with negative impact on oral health, function, and quality of life

INTRODUCTION: Alzheimer's disease (AD) is the most common cause of dementia. The search for new treatments is made more urgent given its increasing prevalence resulting from the aging of the global population. Over the past two decades, stem cell technologies have become an increasingly attractive option to both study and potentially treat neurodegenerative diseases. Several investigators reported a beneficial effect of different types of stem or progenitor cells on the pathology and cognitive function in AD models. Mouse models are among the most important research tools for AD treatment discovery. We aimed to explore the possible therapeutic potential of human umbilical cord mesenchymal stem cell xenografts in a transgenic (Tg) mouse model of AD. METHODS: APP/PS1 Tg AD model mice received human umbilical cord stem cells, directly injected into the carotid artery. To test the efficacy of the umbilical cord stem cells in this AD model, behavioral tasks (sensorimotor and cognitive tests) and immunohistochemical quantitation of the pathology was performed. RESULTS: Treatment of the APP/PS1 AD model mice, with human umbilical cord stem cells, produced a reduction of the amyloid beta burden in the cortex and the hippocampus which correlated with a reduction of the cognitive loss. CONCLUSION: Human umbilical cord mesenchymal stem cells appear to reduce AD pathology in a transgenic mouse model as documented by a reduction of the amyloid plaque burden compared to controls. This amelioration of pathology correlates with improvements on cognitive and sensorimotor tasks.

Introduction: Slow wave sleep (SWS) is thought to benefit spatial memory consolidation. This study investigates whether disrupting SWS via sleep-stage specific OSA affects spatial memory consolidation and how sleep fragmentation and intermittent hypoxia differentially impact this effect. Methods: We recruited 5 subjects with severe OSA who are well treated and compliant with CPAP. Individual subjects spent 3 different nights in the lab and performed timed trials before and after sleep on unique but equally difficult 3D spatial mazes. The 3 conditions included: 1) consolidated sleep with treated OSA 2) CPAP withdrawn exclusively in SWS (SWS-OSA) and 3) CPAP withdrawn exclusively in SWS with simultaneous addition of supplemental oxygen (SWS-OSA+O2). Results: CPAP withdrawal in SWS both decreased %SWS (21% +/- 11% during consolidated sleep vs. 13% +/- 7% with SWS-OSA), and fragmented remaining SWS (SWS apnea hypopnea index with 3% oxygen desaturation or arousal (AHI3A) = 0.5/hour +/- 1 during consolidated sleep vs. 36/hour +/- 12 with SWS-OSA). During SWSOSA+ O2, SWS was also reduced (11% +/ 8%) and respiratory events continued (AHI3A 31/hour +/- 20), however indices of oxygen desaturation were minimized (%time below 90% in SWS = 4.3% +/- 1.7% during SWS-OSA vs 0.5% +/- 0.9% during SWS-OSA+O2; average oxygen saturation during respiratory event = 88.7% +/- 3.3% during SWS-OSA vs. 94% +/- 1.4% during SWS-OSA+O2). During consolidated sleep, median completion time improved from 180 sec pre-sleep (range 86 to 248 sec) to 111 sec post-sleep (range 87 to 412 sec) (38%). During SWS-OSA median completion time improved from 138 sec pre-sleep (range 116 to 272 sec) to 133 sec post-sleep (range 73 to 453 sec) (4%) and during SWS-OSA+O2 median completion time improved from 172 sec pre-sleep (range 61 to 339 sec) to 161 sec postsleep (range 51 to 306 sec) (6%). Conclusion: CPAP withdrawal during SWS in subjects with severe OSA reduces and fragments SWS. The addition of supplemental oxygen during CPAP withdrawal minimizes the associated intermittent hypoxia. Early evidence suggests a greater benefit of consolidated sleep on overnight change in spatial navigation performance than sleep with SWS disruption either with or without intermittent hypoxia

Aims Glucocorticoid resistance is a risk factor for Alzheimer's disease (AD). Molecular and cellular mechanisms of glucocorticoid resistance in the brain have remained unknown and are potential therapeutic targets. Phosphorylation of glucocorticoid receptors (GR) by brain-derived neurotrophic factor (BDNF) signaling integrates both pathways for remodeling synaptic structure and plasticity. OBJECTIVES: To test (i) the role of the BDNF-dependent pathway on glucocorticoid signaling in a mouse model of glucocorticoid resistance, (ii) its influence on dendritic spine loss and tau phosphorylation as risk factors for AD, and (iii) its relevance for human pathology. Method We manipulated (1) BDNF signaling using a TrkB mutant that can be inactivated chemically, (2) glucocorticoid signaling using a BDNF insensitive GR mutant, and (3) the expression of DUSP1, the MAPK-phosphatase downstream of BDNF and GR pathways in a mouse model of glucocorticoid resistance featuring impaired cortisol awaking response. Synaptic defects and Tau phosphorylation were analyzed post-mortem. DUSP1 expression in human brain was analyzed in correlation to AD diagnosis and cognitive impairment in two independent American cohorts (10 controls + 15 AD and 17 controls + 29 AD). Results Deletion of GR phosphorylation at BDNF-responding sites and downstream signaling via DUSP1 triggers tau phosphorylation and dendritic spine atrophy in mouse cortex. In human cortex, DUSP1 protein expression correlates with tau phosphorylation, synaptic defects and cognitive decline in subjects diagnosed with AD. Conclusion Our findings provide evidence for a causal role of BDNF-dependent GR signaling on tau neuropathology and indicate that DUSP1 is potential target of therapeutics

Dopamine (DA) transmission is governed by processes that regulate release from axonal boutons in the forebrain and the somatodendritic compartment in midbrain, and by clearance by the DA transporter, diffusion, and extracellular metabolism. We review how axonal DA release is regulated by neuronal activity and by autoreceptors and heteroreceptors, and address how quantal release events are regulated in size and frequency. In brain regions densely innervated by DA axons, DA clearance is due predominantly to uptake by the DA transporter, whereas in cortex, midbrain, and other regions with relatively sparse DA inputs, the noradrenaline transporter and diffusion are involved. We discuss the role of DA uptake in restricting the sphere of influence of DA and in temporal accumulation of extracellular DA levels upon successive action potentials. The tonic discharge activity of DA neurons may be translated into a tonic extracellular DA level, whereas their bursting activity can generate discrete extracellular DA transients

Aggression is a costly behavior, sometimes with severe consequences including death. Yet aggression is prevalent across animal species ranging from insects to humans, demonstrating its essential role in the survival of individuals and groups. The question of how the brain decides when to generate this costly behavior has intrigued neuroscientists for over a century and has led to the identification of relevant neural substrates. Various lesion and electric stimulation experiments have revealed that the hypothalamus, an ancient structure situated deep in the brain, is essential for expressing aggressive behaviors. More recently, studies using precise circuit manipulation tools have identified a small subnucleus in the medial hypothalamus, the ventrolateral part of the ventromedial hypothalamus (VMHvl), as a key structure for driving both aggression and aggression-seeking behaviors. Here, we provide an updated summary of the evidence that supports a role of the VMHvl in aggressive behaviors. We will consider our recent findings detailing the physiological response properties of populations of VMHvl cells during aggressive behaviors and provide new understanding regarding the role of the VMHvl embedded within the larger whole-brain circuit for social sensation and action.

Weather, in particular the intensity and duration of sunshine (luminance), has been shown to significantly affect financial markets. Yet, because of the complexity of market interactions we do not know how human behavior is affected by luminance in a way that could inform theoretical choice models. In this paper, we use data from a field study using an incentive-compatible, decision task conducted daily over a period of two years and from the US Earth System Research Laboratory luminance sensor to investigate the impact of luminance on risk preferences, ambiguity preferences, choice consistency and dominance violations. We find that luminance levels affect all of these. Age and gender influence the strength of some of these effects.