► REM-rich sleep enhances consolidation of emotional compared to neutral pictures. ► ERP positivity 300–500ms to familiar emotional pictures is enhanced after REM sleep. ► REM-rich sleep does not ...affect subjective ratings of emotional pictures. ► ERP positivity 500–800ms is unchanged for familiar emotional pictures after REM sleep.
Emotional memories are vividly remembered for the long-term. Rapid eye movement (REM) sleep has been repeatedly proposed to support the superior retention of emotional memories. However, its exact contribution and, specifically, whether its effect is mainly on the consolidation of the contents or the processing of the affective component of emotional memories is not clear. Here, we investigated the effects of sleep rich in slow wave sleep (SWS) or REM sleep on the consolidation of emotional pictures and the accompanying changes in affective tone, using event-related potentials (ERPs) together with subjective ratings of valence and arousal. Sixteen healthy, young men learned 50 negative and 50 neutral pictures before 3-h retention sleep intervals that were filled with either SWS-rich early or REM sleep-rich late nocturnal sleep. In accordance with our hypothesis, recognition was better for emotional pictures than neutral pictures after REM compared to SWS-rich sleep. This emotional enhancement after REM-rich sleep expressed itself in an increased late positive potential of the ERP over the frontal cortex 300–500ms after stimulus onset for correctly classified old emotional pictures compared with new emotional and neutral pictures. Valence and arousal ratings of emotional pictures were not differentially affected by REM or SWS-rich sleep after learning. Our results corroborate that REM sleep contributes to the consolidation of emotional contents in memory, but suggest that the affective tone is preserved rather than reduced by the processing of emotional memories during REM sleep.
Extensive research has been accumulated demonstrating that sleep is essential for processes of memory consolidation in adults. In children and infants, a great capacity to learn and to memorize ...coincides with longer and more intense sleep. Here, we review the available data on the influence of sleep on memory consolidation in healthy children and infants, as well as in children with attention-deficit/hyperactivity disorder (ADHD) as a model of prefrontal impairment, and consider possible mechanisms underlying age-dependent differences. Findings indicate a major role of slow wave sleep (SWS) for processes of memory consolidation during early development. Importantly, longer and deeper SWS during childhood appears to produce a distinctly superior strengthening of hippocampus-dependent declarative memories, but concurrently prevents an immediate benefit from sleep for procedural memories, as typically observed in adults. Studies of ADHD children point toward an essential contribution of prefrontal cortex to the preferential consolidation of declarative memory during SWS. Developmental studies of sleep represent a particularly promising approach for characterizing the supra-ordinate control of memory consolidation during sleep by prefrontal-hippocampal circuitry underlying the encoding of declarative memory.
•We compared effects of SWS and REM sleep on consolidation of emotional memories.•REM sleep benefits consolidation of item aspects of emotional memory.•SWS supports consolidation of some source ...aspects of emotional memory.•Relevance of the item-source-associations seems to modulate SWS-associated effects.
Sleep benefits the consolidation of emotional memories, and this influence is commonly attributed to the rapid eye movement (REM) stage of sleep. However, the contributions of sleep stages to memory for an emotional episode may differ for the event per se (i.e., item memory), and the context in which it occurred (source memory). Here, we examined the effects of slow wave sleep (SWS) and REM sleep on the consolidation of emotionally negative and neutral item (picture recognition) and source memory (recall of picture-location and picture-frame color association) in humans. In Study 1, the participants (n=18) learned 48 negative and 48 neutral pictures which were presented at specific locations and preceded by colored frames that had to be associated with the picture. In a within-subject design, learning was either followed by a 3-h early-night SWS-rich or by a late-night REM sleep-rich retention interval, then retrieval was tested. Only after REM-rich sleep, and not after SWS-rich sleep, was there a significant emotional enhancement, i.e., a significantly superior retention of emotional over neutral pictures. On the other hand, after SWS-rich sleep the retention of picture-frame color associations was better than after REM-rich sleep. However, this benefit was observed only for neutral pictures; and it was completely absent for the emotional pictures. To examine whether this absent benefit reflected a suppressive effect of emotionality on associations of minor task relevance, in Study 2 we manipulated the relevance of the picture-frame color association by combining it with information about monetary reward, following otherwise comparable procedures. Here, rewarded picture-frame color associations were equally well retained over SWS-rich early sleep no matter if the frames were associated with emotional or neutral pictures. Results are consistent with the view that REM sleep favors the emotional enhancement of item memory whereas SWS appears to contribute primarily to the consolidation of context-color information associated with the item.
Artificial light at night (ALAN) is negatively impacting numerous species of nocturnally active birds. Nocturnal positive phototaxis, the movement towards ALAN, is exhibited by many marine birds and ...can result in stranding on land. Seabird species facing major population declines may be most at risk. Leach's Storm-Petrels (Hydrobates leucorhous) are small, threatened seabirds with an extensive breeding range in the North Atlantic and North Pacific Oceans. The Atlantic population, which represents approximately 40-48% of the global population, is declining sharply. Nocturnal positive phototaxis is considered to be a key contributing factor. The Leach's Storm-Petrel is the seabird species most often found stranded around ALAN in the North Atlantic, though there is little experimental evidence that reduction of ALAN decreases the occurrence of stranded storm-petrels. During a two-year study at a large, brightly illuminated seafood processing plant adjacent to the Leach's Storm-Petrel's largest colony, we compared the number of birds that stranded when the lights at the plant were on versus significantly reduced. We recorded survival, counted carcasses of adults and juveniles, and released any rescued individuals. Daily morning surveys revealed that reducing ALAN decreased strandings by 57.11% (95% CI: 39.29% - 83.01%) per night and night surveys revealed that reducing ALAN decreased stranding of adult birds by 11.94% (95% CI: 3.47% - 41.13%) per night. The peak stranding period occurred from 25 September to 28 October, and 94.9% of the birds found during this period were fledglings. These results provide evidence to support the implementation of widespread reduction and modification of coastal artificial light as a conservation strategy, especially during avian fledging and migration periods.
Despite their importance in marine food webs, much has yet to be learned about the spatial ecology of small seabirds. This includes the Leach's storm-petrel Oceanodroma leucorhoa, a species that is ...declining throughout its Northwest Atlantic breeding range. In 2013 and 2014, we used global location sensors to track foraging movements of incubating storm-petrels from 7 eastern Canadian breeding colonies. We determined and compared the foraging trip and at-sea habitat characteristics, analysed spatial overlap among colonies, and determined whether colony foraging ranges intersected with offshore oil and gas operations. Individuals tracked during the incubation period made 4.0 ± 1.4 day foraging trips, travelling to highly pelagic waters over and beyond continental slopes which ranged, on average, 400 to 830 km from colonies. Cumulative travel distances ranged from ~900 to 2,100 km among colonies. While colony size did not influence foraging trip characteristics or the size of areas used at sea, foraging distances tended to be shorter for individuals breeding at the southern end of the range. Core areas did not overlap considerably among colonies, and individuals from all sites except Kent Island in the Bay of Fundy foraged over waters with median depths > 1,950 m and average chlorophyll a concentrations ≤ 0.6 mg/m3. Sea surface temperatures within colony core areas varied considerably (11-23°C), coincident with the birds' use of cold waters of the Labrador Current or warmer waters of the Gulf Stream Current. Offshore oil and gas operations intersected with the foraging ranges of 5 of 7 colonies. Three of these, including Baccalieu Island, Newfoundland, which supports the species' largest population, have experienced substantial declines in the last few decades. Future work should prioritize modelling efforts to incorporate information on relative predation risk at colonies, spatially explicit risks at-sea on the breeding and wintering grounds, effects of climate and marine ecosystem change, as well as lethal and sub-lethal effects of environmental contaminants, to better understand drivers of Leach's storm-petrel populations trends in Atlantic Canada.
This study examines the occurrence and underlying factors of onshore strandings of two species of seabirds breeding in Newfoundland and Labrador, Canada. Atlantic Puffins (Fratercula arctica) are ...found stranded in coastal communities bordering the Witless Bay Ecological Reserve in artificially lit areas. Between 2011 and 2020, 3845 recently fledged puffins were found during nightly searches. Counts of puffins found per night were related to the phase of the moon, with the fewest birds found around the full moon. Mean annual body mass of pufflings was positively associated with annual recovery rates, providing a non-intrusive approach to monitor inter-annual productivity at the colony. Using two approaches to estimate population impacts of strandings, we estimate that < 0.2% of fledging chicks were attracted to lights emitted from coastal communities. Despite bordering two of the largest Leach's Storm-Petrel (Oceanodroma leucorhoa) colonies in Newfoundland, this species was rarely observed stranded in the Witless Bay area. Rather, most of the 1903 stranded storm-petrels reported in 2018 and 2019 were found on industrial properties bordering, or inland of, Conception Bay, at minimal distances of 25 km inland from the Witless Bay Ecological Reserve. Most storm-petrels were recently fledged juveniles. Strandings were less likely to occur around the full moon. Neither strong nor persistent winds were observed during nights of large stranding events, however, these nights tended to have winds coming from the north, suggesting that stranded storm-petrels fledged from Baccalieu Island, located at the mouth of Conception Bay and hosting the largest colony in the world. Stronger mitigation measures to avoid and minimize light emittance, as well as research investigating light characteristics to reduce attraction, are urgently needed to decrease unnecessary strandings, particularly for the Leach's Storm-Petrel, recently assessed as Threatened by the Committee on the Status of Endangered Wildlife in Canada.
A variety of anthropogenic threats cause mortality and population declines of procellariiform seabirds. Globally, fledglings of many colonial procellariiforms become stranded in towns and cities ...during their first flights from the nest, which occur at night. Since the 1960s, when the phenomenon became widely known, these strandings have been largely attributed to attraction toward artificial lights at night (ALAN). Artificial light attraction has been blamed due to the predictable, annual nature of strandings; the large numbers of birds found in lighted areas during stranding events; and the inexperience of fledglings in interpreting sensory stimuli. However, up‐to‐date, few alternative hypotheses to that of light attraction have been suggested, and few if any have been explored experimentally. In this paper, we do not seek to refute the light attraction hypothesis. Instead, our objectives are threefold. We wish to (1) highlight the current evidence for light attraction in procellariiforms; (2) identify where evidence may be lacking or subject to confirmation bias; and (3) suggest alternative hypotheses and possible experimental approaches to study them. Given the imperiled nature of many of the affected species and the need to explore and address this source of mortality, our goal in this review is to accelerate and diversify research efforts on this topic.
A Leach's storm‐petrel (Oceanodroma leucorhoa) fledgling sits on a grassy lawn in Newfoundland after becoming stranded the previous night. Photo: Restoration Planet
Brünnich’s guillemot (Uria lomvia), or thick-billed murre, is an abundant pan-Arctic seabird, but several Atlantic breeding populations are declining. The species is subject to traditional harvest in ...the important wintering areas off west Greenland and Newfoundland, and has been subject to chronic oil pollution on the east coast of Canada. Until recently, knowledge of winter distribution has been insufficient to assess the impact of these mortality sources on specific breeding populations. We collate existing information on mortality from bag statistics in Greenland and Canada and studies of oiling off Newfoundland, as well as new data on age distribution in the harvest. Based on the results of recent tracking studies, we construct a spatially explicit population model that allocates hunting and oiling mortality to breeding populations and estimates the relative impact on their growth rate. Results indicate that annual population growth rate is depressed by 0.011–0.041 (approximately 1%–4%) by anthropogenic mortality sources. In addition to affecting local breeders, hunting in Greenland mainly affects declining breeding populations in Svalbard and Iceland, while hunting and oiling in Newfoundland mainly affect guillemots breeding in Arctic Canada and north-west Greenland, where most populations are relatively stable. The strongest relative impact is predicted on the small breeding population in Atlantic Canada, which winters mainly on the Newfoundland Shelf and therefore is exposed to both hunting and oiling. Our results clarify the relationships between hunting in Greenland and Canada and growth of specific breeding populations, and thus have major implications for harvest management of guillemots.
Early diagnosis and treatment of endometriosis affecting adolescent women are important in preventing chronic pain. Our aim was to analyze the clinical characteristics and severity of symptoms in ...adolescent patients with endometriosis compared with older patients.
This single-center retrospective cohort study in a tertiary referral hospital analyzed women whose first consultation at the certified endometriosis center of Bern University Hospital between January 2017 and December 2020 resulted in the clinical diagnosis of endometriosis. Patients, divided into 2 groups by age, reported visual analog scale (VAS) scores for noncyclic pelvic pain, dysmenorrhea, dyschezia, dysuria, and dyspareunia. The symptom types and severity in the 2 groups were compared. The young patients with endometriosis were analyzed in greater detail, comparing VAS scores and types of endometriosis.
From a total of 826 patients, 144 (17.4%) patients 24 years old or younger and 682 (82.6%) patients over 24 years old were compared. The younger patients reported significantly higher pain scores for dysmenorrhea (VAS 7.3 vs 6.6; P = .015), dyspareunia (VAS 4.6 vs 3.4; P = .001), and noncyclic pelvic pain (VAS 4.3 vs 3.7; P = .032) compared with the older patient collective. Similar results were found when excluding patients with hormonal treatment.
Young patients with clinically diagnosed endometriosis have significantly higher dysmenorrhea and dyspareunia pain levels than older patients. By acknowledging and understanding this, early diagnosis and adequate treatment can be promoted. Dyspareunia in adolescents in particular merits clinical attention.
Core-shell nanoparticles (CSNPs) were developed to get over therapeutic amount of kynurenic acid (KYNA) across the blood–brain barrier (BBB). Bovine serum albumin (BSA) was used as core for ...encapsulation of KYNA and the BSA/KYNA composite was finally encapsulated by poly(allylamine) hydrochloride (PAH) polymer as shell. In the interest of the optimization of the synthesis the BSA and KYNA interaction was studied by two-dimensional surface plasmon resonance (SPR) technique as well. The average size of d~100nm was proven by dynamic light scattering (DLS) and transmission electron microscopy (TEM), while the structure of the composites was characterized by fluorescence (FL) and circular dichroism (CD) spectroscopy. The in vitro release properties of KYNA were investigated by a vertical diffusion cell at 25.0°C and 37.5°C and the kinetic of the release were discussed. The penetration capacity of the NPs into the central nervous system (CNS) was tested by an in vitro BBB model. The results demonstrated that the encapsulated KYNA had significantly higher permeability compared to free KYNA molecules. In the neurobiological serial of in vivo experiments the effects of peripherally administered KYNA with CSNPs were studied in comparison with untreated KYNA. These results clearly proved that KYNA in the CSNPs, administrated peripherally is suitable to cross the BBB and to induce electrophysiological effects within the CNS. As the neuroprotective properties of KYNA nowadays are proven, the importance of the results is obvious.
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