The hypocretin peptides are two hypothalamic peptides known to be involved in both sleeping and feeding behavior, however their specific roles in these domains are not well understood. The present study sought to determine the effect of chronic (72-hour) sleep deprivation and (48-hour) food deprivation on preprohypocretin (PPH), which is the precursor for the hypocretin peptides. PPH levels were visualized and quantified via in situ hybridization. A three-factor ANOVA ( group x dorsal/ventral x medial/lateral) revealed a significant effect of subregion, specifically dorsal/middle and ventral/medial exhibited elevated PPH levels, however there was no effect of group. A between group one-way ANOVA revealed no effect of group on PPH levels. It is theorized that four possible domains may be responsible for these results: presence of hypothalamic neuronal subpopulations, role of circadian rhythm, role of hypocretins in locomotive behavior and inextricably confounded variables. These are discussed at length.

Contemporary understanding of the brain indicates that a reciprocal relationship exists between mind and body. Biological functioning adjusts to the consequences of our behavior and our behavior is influenced by our biology. This is the case with the stress responsivity system. The stress hormone cortisol follows a biologically-predetermined daily cycle of secretion (controlled by circadian rhythm) that correlates with expected activity throughout the day, however this cycle can accommodate to different environmental changes that can occur. It has been noticed that individuals who report stress problems also report sleep problems. I hypothesized that sleep quality can predict maladjustments in cortisol’s rhythm. All participants provided saliva samples and had to take the Pittsburgh Sleep Quality Index (PSQI). Salivivay cortisol was measured via was enzyme-immuno-assayed for cortisol. I analyzed the data for three independent studies: (1)12 samples were taken for basal and lab days in 65 individuals. People who scored worse in total PSQI showed decreased stress reactivity (γ 21=-.02, t(63)=-2.27, p=0.026) and faster recovery (γ31=-0.102, t(608)=-2.044, p=0.041). (2)6-8 samples per day across 5 days in 120 maltreated or control adolescents. I used a 3-level hierarchical linear model to examine rhythms within each day and within each individual. The cortisol rhythm was flattened on days when adolescents had poor sleep latency (β;=.013, p=.025 for time-since-waking, β=-.0008, p=.039 for quadratic time-since-waking). (3) 10 samples were taken in 44 skydivers for jumping and basal days. Those who scored worse in sleep latency had slower reactivity (γ31=-0.16, t(284)=-3.701, p<.001) and slower recovery (γ31=0.22, t(284)=3.311, p<0.001). Stress and sleep problems are related to cognitive and physiological issues; finding an appropriate connection between them can be elemental in preventing problems.

Neural oscillations are a ubiquitous form of neural activity seen across scales and modalities. These neural rhythms correlate with diverse cognitive functions and brain states. One mechanism for changing the oscillatory dynamics of large neuronal populations is through neuromodulator activity. An intriguing phenomenon explored here is when local neuromodulation of a distinct neuron type within a single brain nucleus exerts a powerful influence on global cortical rhythms. One approach to investigate the impact of local circuits on global rhythms is through optogenetic techniques. My first project involves the statistical analysis of electrophysiological recordings of an optogenetically-mediated Parkinsonian phenotype. Empirical studies demonstrate that Parkinsonian motor deficits correlate with the emergence of exaggerated beta frequency (15-30 Hz) oscillations throughout the cortico-basal ganglia-thalamic network. However, the mechanism of these aberrant oscillatory dynamics is not well understood. A previous modeling study predicted that cholinergic neuromodulation of medium spiny neurons in the striatum of the basal ganglia may mediate the pathologic beta rhythm. Here, this hypothesis was tested using selective optogenetic stimulation of striatal cholinergic interneurons in normal mice; stimulation robustly and reversibly amplified beta oscillations and Parkinsonian motor symptoms. The modulation of global rhythms by local networks was further studied using computational modeling in the context of intrathalamic neuromodulation. While intrathalamic vasoactive intestinal peptide (VIP) is known to cause long-lasting excitation in vitro, its in vivo dynamical effects have not been reported. Here, biophysical computational models were used to elucidate the impact of VIP on thalamocortical dynamics during sleep and propofol general anesthesia. The modeling results suggest that VIP can form robust sleep spindle oscillations and control aspects of sleep architecture through a novel homeostatic mechanism. This homeostatic mechanism would be inhibited by general anesthesia, representing a new mechanism contributing to anesthetic-induced loss of consciousness. While the previous two projects differed in their use of empirical versus theoretical methods, a challenge common to both domains is the difficulty in visualizing and analyzing large multi-dimensional datasets. A tool to mitigate these issues is introduced here: GIMBL-Vis is a Graphical Interactive Multi-dimensional extensiBLe Visualization toolbox for Matlab. This toolbox simplifies the process of exploring multi-dimensional data in Matlab by providing a graphical interface for visualization and analysis. Furthermore, it provides an extensible open platform for distributed development by the community.

Most sleep deprivation studies show increased body mass, increased hypertension, increased Type 2 Diabetes, obesity, cardiovascular issues and even death. There is a paucity of research in sleeping patterns of first time Caucasian mothers of babies between six and twelve months old in South Africa. The objective was to determine the impact of long-term partial sleep deprivation on metabolism and mood in these mothers. A qualitative and quantitative study using a small sample of thirty one mothers was undertaken. Interviews assessed age, education, anthropometric data, family history, medication use, and baby sleeping habits. Participants were also asked to complete the Pittsburgh Sleep Quality Index (PSQI) and the Becks Depression Inventory II (BDI-II)to assess the mothers sleep quality and depressive state. Medication use significantly decreased sleep quality. Oral contraceptive use and depression (BDI-II score 14-40) were associated with a significantly higher PSQI score and significantly decreased number of hours sleep and sleep efficiency. Oral contraceptive users were significantly more depressed. The six mothers on antidepressants had significantly higher PSQI scores than those not on antidepressants, but hours of sleep and sleep efficiency were not significantly different. This study showed that sleep deprivation did not impact mothers anthropometry. Interestingly medication use affected sleep quality more than baby arousals.

No description available.

Ph.D., Faculty of Science, University of the Witwatersrand, 2011 / This study investigated the effect of exogenous melatonin administration on transient global cerebral ischemia and adult neurogenesis in adult male Sprague- Dawley rats. It also determined serum melatonin concentrations in all the experimental groups and established any effect of melatonin on estimated total granule cell numbers. Adult male Sprague-Dawley rats were divided into eight groups with each group consisting of 6 rats (n = 6). Post-induction time durations of 72 hours and 7 days was used. Single dose of 5 mg/kg exogenous melatonin was administered at each phases of 30 minutes before and after a 10 minutes transient bilateral occlusion of the common carotid arteries in the different groups, followed by reperfusion. Rats were anesthetized with 20 mg/kg of ketamine and 2.5 mls of blood was collected via cardiac puncture for estimation of serum melatonin concentration using commercially prepared radioimmunoassay ELISA kit. Free floating brain sections cut at 50 μm were immunostained for Ki-67, marker for proliferating cells. The total granule cell number in the dentate gyrus was estimated using the optical fractionator method on plastic embedded brain sections. Mean melatonin concentration (pg/mol) was 268.54 ± 28.73 (72 hours) and 277.83 ± 28.73 (7 days) compared to the sham control; 266.94 ± 37.6 and non surgical 262.96 ± 23.85 respectively. Differences in the concentration were not statistically significant (P<0.05). Histological finding indicated neuropil disruption with potentiation of restoration as the post ischemia days progressed in the melatonin administered groups. The estimated total granule cell number in the dentate gyrus of the hippocampus was not affected by exogenous melatonin administration. However, there was potentiation in proliferations of the neurogenic niche in the dentate gyrus of the hippocampus demonstrating a very strong indications that melatonin enhanced the generations of proliferating cells in adult male Sprague-Dawley rats.

Thesis advisor: Elizabeth Kensinger / Thesis advisor: Katherine Mickley / Current research suggests that viewing complex scenes composed of a background and a negative, centralized image results in an emotion-induced memory trade-off. This trade-off is often characterized by high rates of memory accuracy for negative central images at the expense of a neutral background. In the present study, I explored whether the same trade-off effect is present for positive emotional stimuli. Therefore, when viewing complex scenes composed of a background and a positive central image, do people tend to remember the positive image more than they do the background? I examined two related research questions: (1) will positive scene components elicit an emotional memory trade-off effect? and (2) how does the passage of time, with and without sleep, influence positive scene components in comparison to negative scene components? Participants were separated into a sleep group and a wake group. The experiment consisted of two parts: the first was a viewing of 90 compound scenes and the second included a memory recognition test. Although the trade-off effect was present for negative valence items as well as positive objects, no main group effect was found. In other words, the emotional memory trade-off effect was not enhanced with sleep. / Thesis (BA) — Boston College, 2010. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Psychology Honors Program. / Discipline: Psychology.

Among all symptoms of Parkinson’s Disease (PD), depression and sleep dysfunction have the highest impact on quality of life, yet sleep disturbances and depression symptoms are often left unrecognized and untreated. With the rising annual cost of pharmacologic treatments for PD and the increasing prevalence of PD in the United States, there is a need to implement effective non-pharmacologic regimens, such as physical exercise. Adherence to exercise regimens can often be challenging, especially for elderly patients with progressive neurological impairment. However, enjoyable exercises, such as dancing, involve socialization and musical stimuli that are associated with increased motivation in patients. Dance exercise has been shown to have significant improvement in motor symptoms, functional mobility, mood, and quality of life in PD patients compared to no intervention or traditional exercises. Previous studies have shown that Tango style dancing has additional benefits for PD patients as it may selectively activate areas of the brain associated with motor and non-motor symptoms (the basal ganglia and anterior putamen, respectively) during backward walking and metered rhythmic movement. However, no studies have yet investigated the effect of dance intervention on sleep quality in patients with PD. The proposed study is a randomized control trial that will compare the sleep quality improvement of 90 elderly PD patients in two treatment arms, a Tango dance intervention with walking and walking alone (control group). The Tango group will participate in a 6-month Adapted Tango class designed for PD patients. Sleep quality will be measured as the primary outcome using the Parkinson’s Disease Sleep Scale (PDSS-2). Depression will be measured as a secondary outcome using the BDI-II. This will be the first study to investigate the effects of dance intervention on sleep quality in patients with PD, applying an adapted Tango program similar to those used in previous studies. If the results of this study reveal positive effects of Tango on sleep quality, clinicians may be able to recommend Tango-style dance exercise as a therapeutic intervention to target sleep disturbances and improve quality of life for patients with PD.

Carta al Editor

A key feature of sleep is reduced responsiveness to the environment, which puts animals in a particularly vulnerable state; yet, sleep has been conserved throughout evolution, indicating that it fulfills a vital purpose. A core function of sleep across species has not been identified, but substantial advances in sleep research have been made in recent years using the genetically tractable model organism, Drosophila melanogaster. While a standard approach in sleep research is to study the effects of short-term sleep deprivation on an animal, tools are now available to genetically manipulate sleep amount in the fruit fly. In particular, a number of short-sleeping Drosophila mutants have been identified that model the long-term sleep restriction that is widespread in modern society. This thesis describes a body of work in which short-sleeping Drosophila mutants, as well as other genetic and pharmacological tools, were used to shed light on the function and regulation of sleep.