Fear of the unknown: a pre-departure qualitative study of Turkish international students

This paper presents findings from eleven in-depth interviews with Turkish undergraduate students, who were, by the time of data collection, about to spend a semester at a European university under the Erasmus exchange scheme. The students all agreed to be interviewed about their feelings about studying in a foreign culture, and were found to be anxious prior to departure about the quality of accommodation in the new destination, their language ability and the opportunity to form friendships. Fears were expressed about possible misconceptions over Turkey as a Muslim and a developing country. Suggestions are made for HEI interventions to allay student travellers’ concerns

Seasonal change in the daily timing of behaviour of the common vole, Microtus arvalis

1. Seasonal effects on daily activity patterns in the common vole were established by periodic trapping in the field and continuous year round recording of running wheel and freeding activity in cages exposed to natural meteorological conditions. 2. Trapping revealed decreased nocturnality in winter as compared to summer. This was paralelled by a winter reduction in both nocturnal wheel running and feeding time in cages. 3. Frequent trap checks revealed a 2 h rhythm in daytime catches in winter, not in summer. Cage feeding activity in daytime was always organized in c. 2 h intervals, but day-to-day variations in phase blurred the rhythm in summer in a summation of individual daily records. Thus both seasonal and short-term temporal patterns are consistent between field trappings and cage feeding records. 4. Variables associated with the seasonal change in daily pattern were: reproductive state (sexually active voles more nocturnal), age (juveniles more nocturnal), temperature (cold days: less nocturnal), food (indicated by feeding experiments), habitat structure (more nocturnal in habitat with underground tunnels). 5. Minor discrepancies between field trappings and cage feeding activity can be explained by assuming increased trappability of voles in winter. Cage wheel running is not predictive of field trapping patterns and is thought to reflect behavioral motivations not associated with feeding but with other activities (e.g., exploratory, escape, interactive behaviour) undetected by current methods, including radiotelemetry and passage-counting. 6. Winter decrease in nocturnality appears to involve a reduction in nocturnal non-feeding and feeding behaviour and is interpreted primarily as an adaptation to reduce energy expenditure in adverse but socially stable winter conditions.

Mouse models of preeclampsia with preexisting comorbidities

Preeclampsia is a pregnancy-specific condition and a leading cause of maternal and fetal morbidity and mortality. It is thought to occur due to abnormal placental development or dysfunction, because the only known cure is delivery of the placenta. Several clinical risk factors are associated with an increased incidence of preeclampsia including chronic hypertension, diabetes, autoimmune conditions, kidney disease, and obesity. How these comorbidities intersect with preeclamptic etiology, however, is not well understood. This may be due to the limited number of animal models as well as the paucity of studies investigating the impact of these comorbidities. This review examines the current mouse models of chronic hypertension, pregestational diabetes, and obesity that subsequently develop preeclampsia-like symptoms and discusses how closely these models recapitulate the human condition. Finally, we propose an avenue to expand the development of mouse models of preeclampsia superimposed on chronic comorbidities to provide a strong foundation needed for preclinical testing

Psilocybin prevents symptoms of hyperarousal and enhances novel object recognition in rats exposed to the single prolonged stress paradigm

Pharmacotherapy for stress-related psychological disorders remains inadequate. Patients who are treated with conventional pharmacological agents frequently report negligeable symptom reduction, and, in most cases, less than 50% experience full remission. Clearly, there is a need for additional pharmaceutical research into both established and novel approaches to alleviate these conditions. Over the past several years, there has been a renewed interest in the use of psychedelics to aid in the treatment of psychological disorders. Several studies have reported promising results in patients with major depression, anxiety disorders, and post-traumatic stress disorder (PTSD) following treatment with psychedelic agents such as lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), ayahuasca, ketamine, and psilocybin. However, the precise behavioral and neurobiological mechanisms for these effects remain unclear. Thus, we aimed to develop an animal model of PTSD that involved prophylactic treatment with psilocybin, a 5-HT2A agonist, that could be used to further understand the mechanisms underlying the benefit of psychedelic substances in treating these disorders. Adult male and female Sprague-Dawley rats were subjected to the single prolonged stress (SPS) paradigm, including 2 hours of physical restraint, 15 minutes of forced swim, and ether vapor exposure until loss of consciousness. Five minutes following ether-induced loss of consciousness, the rats were intraperitoneally injected with vehicle (0.9% saline) or psilocybin (1 mg/kg). One week later, the rats underwent a battery of behavioral tests, including the elevated plus maze (EPM), startle response assessment, open field testing, and novel object recognition (NOR) testing. No effects of SPS or psilocybin were observed for EPM behavior. SPS led to enhanced startle responses in males, but not females, which was prevented by psilocybin. SPS also increased locomotor activity in the open field in males, but not females, and this effect was not prevented by psilocybin. SPS had no impact on NOR memory in males, but enhanced memory in females. Interestingly, psilocybin administration, alone or in combination with SPS, enhanced NOR memory in males only. These findings support a complex interaction between the administration of psilocybin and the prevention of stress-induced behavioral sequelae that depends on both sex and the type of behavioral task

Low-dose psilocybin enhances novel object recognition but not inhibitory avoidance in adult rats

Given the recently renewed interest in using psychedelics to aid in the treatment of psychological disorders, we aimed to examine the impact of psilocybin, a 5-HT2A agonist, on learning and memory in rodents. Previous work has demonstrated that psilocybin and other 5-HT2A agonists can enhance fear conditioning, fear extinction, and novel object recognition (NOR). Thus, we predicted that low doses of psilocybin would enhance inhibitory avoidance (IA) and NOR memory. In the first experiment, adult male and female Sprague-Dawley rats underwent step-through IA training (involving 0.45, 0.65, or 1 mA scrambled footshock) and were injected intraperitoneally (i.p.) with vehicle (0.9% saline) or psilocybin (1 mg/kg) immediately afterward. Rats were tested for their IA memory two days later. In the second experiment, adult male and female Sprague-Dawley rats were acclimated to an open field apparatus for 5 minutes on Day 1. The next day, the rats were given i.p. injections of vehicle or psilocybin (0.1 mg/kg) 10 minutes before undergoing NOR training, during which they were exposed to two replicas of an identical object for 3 minutes. On Day 3, one of the objects from NOR training was exchanged for a novel object; rats were exposed to this novel object and a new replica of the object from Day 2 (i.e., familiar object) for 5 minutes. The results showed that psilocybin had no significant impact on IA memory but enhanced novel object recognition memory in both males and females. The differential impact of psilocybin on IA memory and novel object recognition could be explained by the different doses of psilocybin or the different times of drug administration used for each task. Alternatively, they may suggest that psilocybin exerts distinct effects on different types of learning

On the influence of the cosmological constant on gravitational lensing in small systems

The cosmological constant Lambda affects gravitational lensing phenomena. The contribution of Lambda to the observable angular positions of multiple images and to their amplification and time delay is here computed through a study in the weak deflection limit of the equations of motion in the Schwarzschild-de Sitter metric. Due to Lambda the unresolved images are slightly demagnified, the radius of the Einstein ring decreases and the time delay increases. The effect is however negligible for near lenses. In the case of null cosmological constant, we provide some updated results on lensing by a Schwarzschild black hole.Comment: 8 pages, 1 figure; v2: extended discussion on the lens equation, references added, results unchanged, in press on PR

Dopamine acting at D1-like, D2-like and α1-adrenergic receptors differentially modulates theta and gamma oscillatory activity in primary motor cortex

The loss of dopamine (DA) in Parkinson’s is accompanied by the emergence of exaggerated theta and beta frequency neuronal oscillatory activity in the primary motor cortex (M1) and basal ganglia. DA replacement therapy or deep brain stimulation reduces the power of these oscillations and this is coincident with an improvement in motor performance implying a causal relationship. Here we provide in vitro evidence for the differential modulation of theta and gamma activity in M1 by DA acting at receptors exhibiting conventional and non-conventional DA pharmacology. Recording local field potentials in deep layer V of rat M1, co-application of carbachol (CCh, 5 μM) and kainic acid (KA, 150 nM) elicited simultaneous oscillations at a frequency of 6.49 ± 0.18 Hz (theta, n = 84) and 34.97 ± 0.39 Hz (gamma, n = 84). Bath application of DA resulted in a decrease in gamma power with no change in theta power. However, application of either the D1-like receptor agonist SKF38393 or the D2-like agonist quinpirole increased the power of both theta and gamma suggesting that the DA-mediated inhibition of oscillatory power is by action at other sites other than classical DA receptors. Application of amphetamine, which promotes endogenous amine neurotransmitter release, or the adrenergic α1-selective agonist phenylephrine mimicked the action of DA and reduced gamma power, a result unaffected by prior co-application of D1 and D2 receptor antagonists SCH23390 and sulpiride. Finally, application of the α1-adrenergic receptor antagonist prazosin blocked the action of DA on gamma power suggestive of interaction between α1 and DA receptors. These results show that DA mediates complex actions acting at dopamine D1-like and D2-like receptors, α1 adrenergic receptors and possibly DA/α1 heteromultimeric receptors to differentially modulate theta and gamma activity in M1

A Novel Molecular Solution for Ultraviolet Light Detection in Caenorhabditis elegans

For many organisms the ability to transduce light into cellular signals is crucial for survival. Light stimulates DNA repair and metabolism changes in bacteria, avoidance responses in single-cell organisms, attraction responses in plants, and both visual and nonvisual perception in animals. Despite these widely differing responses, in all of nature there are only six known families of proteins that can transduce light. Although the roundworm Caenorhabditis elegans has none of the known light transduction systems, we show here that C. elegans strongly accelerates its locomotion in response to blue or shorter wavelengths of light, with maximal responsiveness to ultraviolet light. Our data suggest that C. elegans uses this light response to escape the lethal doses of sunlight that permeate its habitat. Short-wavelength light drives locomotion by bypassing two critical signals, cyclic adenosine monophosphate (cAMP) and diacylglycerol (DAG), that neurons use to shape and control behaviors. C. elegans mutants lacking these signals are paralyzed and unresponsive to harsh physical stimuli in ambient light, but short-wavelength light rapidly rescues their paralysis and restores normal levels of coordinated locomotion. This light response is mediated by LITE-1, a novel ultraviolet light receptor that acts in neurons and is a member of the invertebrate Gustatory receptor (Gr) family. Heterologous expression of the receptor in muscle cells is sufficient to confer light responsiveness on cells that are normally unresponsive to light. Our results reveal a novel molecular solution for ultraviolet light detection and an unusual sensory modality in C. elegans that is unlike any previously described light response in any organism

Beat synchronization across the lifespan: intersection of development and musical experience

Rhythmic entrainment, or beat synchronization, provides an opportunity to understand how multiple systems operate together to integrate sensory-motor information. Also, synchronization is an essential component of musical performance that may be enhanced through musical training. Investigations of rhythmic entrainment have revealed a developmental trajectory across the lifespan, showing synchronization improves with age and musical experience. Here, we explore the development and maintenance of synchronization in childhood through older adulthood in a large cohort of participants (N = 145), and also ask how it may be altered by musical experience. We employed a uniform assessment of beat synchronization for all participants and compared performance developmentally and between individuals with and without musical experience. We show that the ability to consistently tap along to a beat improves with age into adulthood, yet in older adulthood tapping performance becomes more variable. Also, from childhood into young adulthood, individuals are able to tap increasingly close to the beat (i.e., asynchronies decline with age), however, this trend reverses from younger into older adulthood. There is a positive association between proportion of life spent playing music and tapping performance, which suggests a link between musical experience and auditory-motor integration. These results are broadly consistent with previous investigations into the development of beat synchronization across the lifespan, and thus complement existing studies and present new insights offered by a different, large cross-sectional sample