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Although the perifornical lateral hypothalamic area (PeFLH), which contains orexin/hypocretin (OX) neurons, plays an important role in arousal-related behaviors, its neuromodulatory inputs are incompletely understood. The present study examined the role of glutamatergic inputs to the PeFLH in various arousal-related behaviors. Adult male rats received a microinjection of the ionotropic glutamate receptor agonists AMPA (1 and 2 mM) or NMDA (1 and 10 mM), or vehicle into the PeFLH, and were placed in an open field; 90 min later, rats were perfused for immunohistochemistry for OX and c-Fos as a marker of neuronal activation. AMPA injections dose-dependently increased locomotion, rearing, and drinking. NMDA injections (at 10 mM) increased locomotion and feeding. All these behaviors (except feeding) were positively correlated with the number of c-Fos/OX-immunoreactive neurons. These results support the role of ionotropic glutamate receptors on OX (and other) neurons in the PeFLH in the regulation of locomotor and ingestive behaviors.

Circadian rhythms are outputs of the internal clock that regulates the daily functions of almost all living organisms. Circadian rhythms are typically 24 hours because they are synchronized by external cues such as the natural light/dark cycles of the environment. When external cues are removed, the circadian rhythm “free-runs,” thus revealing the organism’s endogenous circadian period. Recent studies have found that the trashline orbweaving spiders Cyclosa turbinata and Allocyclosa bifurca have abnormally short circadian rhythms of approximately 19 and 18 hours, respectively. Trashline orbweavers construct a line of debris made of prey carcasses in the center of their web and then remain undetectable by being cryptic within their trashline. Despite similar circadian rhythms and web-building behaviors, recent genetic findings indicate that these species actually are not closely related. In fact, both genetic and morphological data now suggest A. bifurca is more closely related to Cyrtophora citricola, the Tropical Tent-web spider. This would suggest that trashline behavior and exceptionally short circadian clocks evolved independently in C. turbinataand A. bifurca. This study analyzed the circadian rhythm of C. citricola and compared it to the circadian rhythm of A. bifurca. If C. citricola has an abnormally short clock like A. bifurca, this would indicate that the evolution of the short clock preceded the divergence of these species’ lineages. However, if C. citricola has a more typical clock, this would suggest that the unusually short clock evolved in the A. bifurca lineage and may be more ecologically linked to the trashline behavior. Thirty-two female C. citricola were collected in Southern Florida and had their locomotor activity measured over four days of 12:12 light/dark cycles followed by complete darkness to determine their circadian free-running periods (FRP). Cyrtophora citricola was found to have a more typical FRP of 24.0 + 0.43 hours. Despite being closely related, C. citricola and A. bifurca differ significantly in their circadian rhythms, suggesting that short circadian rhythms may be ecologically linked with trashline behavior.

The near absence of bed bugs from human dwellings for fifty or more years has left us with limited knowledge of its biology and few answers to eliminate populations. I explored a diverse set of objectives to answer key questions concerning bed bug biology and control. Major objectives were studies of circadian rhythmicity, pyrethroid resistance, sublethal effects of insecticides, synergism of pyrethroids, and evaluation of a pyrrole insecticides, chlorfenapyr. Additional studies included persistence of Borrelia in bed bugs after ingestion, and aggregation factors from feces. In the absence of host stimuli, insects were much more active in the dark than in the light. Nocturnal activity was periodical under continuous light conditions, which indicates that locomotion is endogenously generated by a circadian clock. Circadian rhythm was entrained to reverse dark-light regimes. Short–term starved adults moved more frequently than long-starved adults. These results suggest that starved bugs reduce locomotor activity as a strategy to conserve metabolic reserves. Pyrethroid resistance in C. lectularius was documented for the first time. Extremely high levels of resistance to deltamethrin and λ-cyhalothrin, was detected in populations collected in Kentucky and Ohio. The resistance ratios reported are among the highest documented in any arthropod. Evaluations of more than 20 populations from across the United States indicate that resistance to pyrethroid insecticides is widespread. Bed bugs avoided resting on surfaces treated with deltamethrin but not with chlorfenapyr. Video recordings of bed bugs showed that insects increased their activity when they contacted sublethal doses of deltamethrin. However, harborages treated with a deltamethrin remained attractive. A nearby heat source overcame avoidance to deltamethrin. The P450 inhibitor piperonyl butoxide (PBO) enhanced toxicity of deltamethrin to resistant bed bugs. However, the residual resistance after PBO treatment indicated that other resistance mechanisms are involved. The effectiveness of combining PBO with pyrethroids varied among populations, which indicates that this synergist is not a comprehensive solution to pyrethroid resistance. Chlorfenapyr was effective against pyrethroid resistant strains. While it does not cause quick knockdown, long residual activity and no avoidance behavior to dry residues appears to make this insecticide a useful tool for bed bug control.

Introduction: Using an animal model, we examined weight gain in rats exposed to olanzapine, as well as whether increased weight was associated with food intake, visceral fat and/or locomotion. Methods: Sprague-Dawley rats were chronically treated with olanzapine while being offered diets including standard chow, a high fat (60% fat) diet, and a high fat/high carbohydrate (42% fat; 42.7% carbohydrate) diet. Body weight, food intake, visceral fat and locomotor activity were measured. Results: Our findings related to weight gain are in line with other reports indicating that while olanzapine-induced weight gain can be observed, it does not mirror what is observed in humans on two levels: (i) it is not of the same magnitude, and (ii) it is more gender specific i.e., females greater than males. Conclusions: These data confirm that chronic treatment with olanzapine has varying effects on weight gain, food intake, visceral fat and locomotor activity.

Introduction: Using an animal model, we examined weight gain in rats exposed to olanzapine, as well as whether increased weight was associated with food intake, visceral fat and/or locomotion. Methods: Sprague-Dawley rats were chronically treated with olanzapine while being offered diets including standard chow, a high fat (60% fat) diet, and a high fat/high carbohydrate (42% fat; 42.7% carbohydrate) diet. Body weight, food intake, visceral fat and locomotor activity were measured. Results: Our findings related to weight gain are in line with other reports indicating that while olanzapine-induced weight gain can be observed, it does not mirror what is observed in humans on two levels: (i) it is not of the same magnitude, and (ii) it is more gender specific i.e., females greater than males. Conclusions: These data confirm that chronic treatment with olanzapine has varying effects on weight gain, food intake, visceral fat and locomotor activity.

Dopamine (DA) drives incentive learning: learning which is elicited through rewarding stimuli. Irregularities in DA activity are associated with various psychological disorders. Glycogen synthase kinase-3β (GSK3β), a molecule downstream of DA receptors, has been implicated in mediating dopaminergic behaviour, and unbalanced DA activity is associated with concomitant irregularities in GSK3β signaling. Inhibition of this molecule has been noted to attenuate behavioural sensitization, and decrease psychotomimetic behaviour in animals. Few studies have assessed the role of GSK3β in the conditioned place preference (CPP) paradigm, which evaluates the rewarding properties of substances and has been used to model psychosis. CPP can be examined through either acquisition or expression paradigms, which look at the active learning process vs. the recall of learned information respectively. We tested the hypothesis that selective inhibition of GSK3β with SB 216763 will differentially and dose-dependently affect the acquisition and expression of amphetamine (AMPH) CPP, as well as attenuate AMPH locomotor activity in acquisition. All drugs and vehicles were administered via intra-cranial microinfusions into the nucleus accumbens. AMPH was administered at a dose of 20.0 μg/0.5 μl/side. SB 216763 was tested at four doses (0.03, 0.30, 3.00, & 5.00 μg/0.5 μl/side) in both acquisition and expression. We found administering SB 216763 at all doses to attenuate AMPH CPP and locomotor activity in acquisition. At doses 0.30, 3.00, & 5.00 μg/0.5 μl/side, SB 216763 also blocked AMPH CPP at expression. These results lend support to GSK3β’s involvement in incentive learning and DA-mediated behaviours, and suggest its inhibition may differentially affect the acquisition and expression of AMPH CPP. / Thesis (Master, Psychology) -- Queen's University, 2014-01-03 15:41:20.989

The presence of artificial light at night (ALAN) is one of many contributing factors to global change today. The spectral range of ALAN can also alter the potential effects of light pollution in certain contexts which creates an exceptionally complex cascade of impacts. The purpose of this thesis was to examine the interactions of various environmental factors including ALAN on biological variables, locomotor activity and corticosterone concentration, of two species of rodent. This was accomplished by manipulating the environmental factors; environmental enrichment, temperature and lighting in captivity. A pilot field study was also conducted in order to test the future feasibility of incorporating information garnered from the laboratory study into larger scale real world experiments. The two species were collected from the field and was subsequently subjected to various light cycles, during which locomotor activity was monitored and urinary corticosterone stress hormone was assessed. Results showed that Micaelamys namaquensis, a nocturnal species, reacted favourably to the addition of enrichment by increasing activity levels whereas Rhabdomys dilectus, a diurnal species decreased activity levels while improving the strength of entrainment. Both M. namaquensis and R. dilectus decreased activity during a light cycle which simulated natural dawn and dusk patterns of light. The two species reacted differently when a 24hr ambient temperature cycle was introduced, with M. namaquensis increasing its locomotor activity and R. dilectus decreasing overall activity. M. namaquensis decreased its average activity in response to ALAN and did not show any difference in reaction towards different types of light at night. R. dilectus on the other hand increased its activity under ALAN but also showed no preference between different spectra of light at night. While corticosterone concentrations were monitored during all the environmental factor experiments, fluctuations in hormone concentrations were noted, however found to be statistically non-significant. Thus, only speculations could be made regarding the impacts of the various environmental factors on the stress physiology of M. namaquensis and R. dilectus. These results highlight the importance of considering species specific outcomes even under virtually identical circumstances. Understanding the impacts of environmental factors is crucial in order to extrapolate laboratory-based findings into real world experiments. This work can be used to further understand the impacts of different environmental factors on the circadian systems of nocturnal and diurnal rodent species as well as the potential implication of ALAN under various environmental conditions. In future, this can be combined into a large-scale field experiment in order to monitor the impacts of light pollution using the methodology elucidated during the pilot study. The results of this study show that the impacts of ALAN can be incredibly diverse and specific to the species in which they are examined. / Dissertation (MSc)--University of Pretoria, 2019. / Zoology and Entomology / MSc / Unrestricted

A major advantage of having behavior controlled by a circadian clock is that the organism may be able to anticipate, rather than respond to, important daily events in its environment. Here, we describe the behavioral rhythms of locomotor activity and web building in the orb-weaving spider Cyclosa turbinata (Walckenaer, 1841). Web building occurs late in the scotophase, in absolute darkness, and is initiated and completed before lights-on under light:dark cycles in the laboratory. This scheduling presumably enables web-building to occur under the cover of darkness, thereby avoiding visual predators. Locomotor activity occurs predominantly in the dark with a sharp peak within one hour after lights-off and a broader peak occurring before lights-on. The locomotor activity rhythm free runs under constant dark and constant temperature conditions, thus indicating endogenous circadian control. Evidence from the free running rhythm suggests that the first peak under light:dark cycles is a result of masking but that the second peak is attributable to the endogenous circadian oscillator. The period of the free run is exceptionally short, about 19 hours. In comparison with locomotor activity, web building is quite sporadic under constant dark conditions, making detection of periodicities difficult and, therefore, whether web-building is under endogenous circadian control or is driven by exogenous factors remains unresolved.

In the field of insect circadian rhythms, the honey bee is best known for its foraging time-sense, or Zeitgedächtnis, which permits the forager bee to make precise associations between the presence of food and the time of day. A number of studies, now considered classics, established that bees could be trained to collect food at virtually any time of the circadian cycle and that this timekeeping ability was controlled by an endogenous circadian clock. Recently, behavioral rhythms in bees have been examined using a variety of approaches, in both laboratory and field studies. The following areas of new research are reviewed: (a) the ontogeny of behavioral rhythmicity in newly emerged worker bees; (b) the integration of behavioral rhythmicity with the colony's division of labor; (c) the evidence for social entrainment of behavioral rhythms and for a 'clock of the colony'; (d) the potential linkage between circadian rhythms of general locomotor activity and the foraging time-sense; (e) learning and entrainment hypotheses proposed to explain the mechanism underlying the time-sense; (f) the interplay between extinction and persistence of the time-memory as revealed from the differential behavior of individuals within the foraging group; and (g) comparisons of the Zeitgedächtnis with food-anticipatory rhythms in other animals.