BCL11B Regulates Arterial Stiffness and Related Target Organ Damage.

[Figure: see text].

Decadal changes in global phytoplankton compositions influenced by biogeochemical variables.

The global environmental changes owing to natural and anthropogenic influences are challenging the structure and functioning of the ocean ecosystem. The complex processes interacting within the physical, chemical, and biological environment at different spatio-temporal scales and their impact on the ocean ecosystem processes are yet to be investigated. A long term trend on phytoplankton biomass in terms of Chlorophyll-a concentration (Chl-a), phytoplankton compositions and the processes that control the variability is required for understanding the ocean ecosystem. This study investigated decadal trends (2002-2015) of phytoplankton composition and biogeochemical parameters over the Global Ocean (GO), Southern Ocean (SO), and the Arctic Ocean (AO) using ocean color remote sensing and assimilated data from the National Aeronautics and Space Administration (NASA) Ocean biogeochemical model. The results revealed the dominance of larger cell phytoplankton mainly diatoms throughout the SO and AO; however, the coccolithophores dominate in the remaining part of the GO. Analysis of nutrients showed that nitrate is not a limiting factor for the variability of phytoplankton biomass in the SO and AO. The low nitrate concentration influenced in the rest of the GO. The photosynthetically available radiation (PAR) limiting the phytoplankton biomass and composition in the SO and AO. Although the SO is known as the high nutrient low chlorophyll (HNLC) region of the GO, the low iron concentration along with the PAR co-limits the growth of phytoplankton biomass. Trend analysis showed that an increase in Chl-a and diatoms in the SO and AO. In contrast, it declined significantly in the other regions of the GO, in response to the consistent increase in sea surface temperature. The results indicated that, shifting of phytoplankton community from regional to global scale have a greater implication for climate change and marine ecosystem.

Redox-Resistant SERCA [Sarco(endo)plasmic Reticulum Calcium ATPase] Attenuates Oxidant-Stimulated Mitochondrial Calcium and Apoptosis in Cardiac Myocytes and Pressure Overload-Induced Myocardial Failure in Mice.

BACKGROUND: SERCA [sarco(endo)plasmic reticulum calcium ATPase] is regulated by oxidative posttranslational modifications at cysteine 674 (C674). Because sarcoplasmic reticulum (SR) calcium has been shown to play a critical role in mediating mitochondrial dysfunction in response to reactive oxygen species, we hypothesized that SERCA oxidation at C674 would modulate the effects of reactive oxygen species on mitochondrial calcium and mitochondria-dependent apoptosis in cardiac myocytes. METHODS: Adult rat ventricular myocytes expressing wild-type SERCA2b or a redox-insensitive mutant in which C674 is replaced by serine (C674S) were exposed to H2O2 (100 µmol/Lµ). Free mitochondrial calcium concentration was measured in adult rat ventricular myocytes with a genetically targeted fluorescent probe, and SR calcium content was assessed by measuring caffeine-stimulated release. Mice with heterozygous knock-in of the SERCA C674S mutation were subjected to chronic ascending aortic constriction. RESULTS: In adult rat ventricular myocytes expressing wild-type SERCA, H2O2 caused a 25% increase in mitochondrial calcium concentration that was associated with a 50% decrease in SR calcium content, both of which were prevented by the ryanodine receptor inhibitor tetracaine. In cells expressing the C674S mutant, basal SR calcium content was decreased by 31% and the H2O2-stimulated rise in mitochondrial calcium concentration was attenuated by 40%. In wild-type cells, H2O2 caused cytochrome c release and apoptosis, both of which were prevented in C674S-expressing cells. In myocytes from SERCA knock-in mice, basal SERCA activity and SR calcium content were decreased. To test the effect of C674 oxidation on apoptosis in vivo, SERCA knock-in mice were subjected to chronic ascending aortic constriction. In wild-type mice, ascending aortic constriction caused myocyte apoptosis, LV dilation, and systolic failure, all of which were inhibited in SERCA knock-in mice. CONCLUSIONS: Redox activation of SERCA C674 regulates basal SR calcium content, thereby mediating the pathologic reactive oxygen species-stimulated rise in mitochondrial calcium required for myocyte apoptosis and myocardial failure.

In the temporal organization of episodic memory, the hippocampus supports the experience of elapsed time.

Space and time are both essential features of episodic memory, for which the hippocampus is critical (Howard & Eichenbaum, 2015). Spatial tasks have been used effectively to study the behavioral relevance of place cells. However, the behavioral paradigms utilized for the study of time cells have not used time duration as a variable that animals need to be aware of to solve the task. Therefore, the behavioral relevance of this cell firing is unclear. In order to directly study the role of the hippocampus in processing elapsed time, we created a novel time duration discrimination task. Rats learned to make a decision to turn left or right depending on the preceding tone duration (10 s, left turn; 20 s, right turn). Once the rats reached criterion performance of 90% correct on two out of three consecutive days, they received either an excitotoxic hippocampal lesion or a sham-lesion surgery. After recovery, rats were tested to determine hippocampal involvement in discriminating time duration. Rats with hippocampal lesions performed at chance level on their first testing day postlesion, and they were impaired relative to the sham-lesioned rats. Although the hippocampal-lesioned rats began discriminating at above chance level, their performance never returned to criterion even with 50 days of postoperative testing. Furthermore, while sham rats showed no difference in the number of errors they made on 10- versus 20-s delay trials, hippocampal lesion rats similarly improved their performance under the 10-s delay condition, but not under the 20-s delay condition. Results indicate that hippocampal lesions resulted in a selective impairment in discriminating elapsed time only during the longer delay trials. The implications of these results are discussed in relation to the limits of working-memory capacity and to the role of sustained hippocampal time cell activity in memory performance depending on the perceived relevance of the delay period.

Medial entorhinal cortex lesions produce delay-dependent disruptions in memory for elapsed time.

Our memory for time is a fundamental ability that we use to judge the duration of events, put our experiences into a temporal context, and decide when to initiate actions. The medial entorhinal cortex (MEC), with its direct projections to the hippocampus, has been proposed to be the key source of temporal information for hippocampal time cells. However, the behavioral relevance of such temporal firing patterns remains unclear, as most of the paradigms used for the study of temporal processing and time cells are either spatial tasks or tasks for which MEC function is not required. In this study, we asked whether the MEC is necessary for rats to perform a time duration discrimination task (TDD), in which rats were trained to discriminate between 10-s and 20-s delay intervals. After reaching a 90% performance criterion, the rats were assigned to receive an excitotoxic MEC-lesion or sham-lesion surgery. We found that after recovering from surgery, rats with MEC lesions were impaired on the TDD task in comparison to rats with sham lesions, failing to return to criterion performance. Their impairment, however, was specific to the longer, 20-s delay trials. These results indicate that time processing is dependent on MEC neural computations only for delays that exceed 10 s, perhaps because long-term memory resources are needed to keep track of longer time intervals.

Minority Participation in Randomized Controlled Trials for Prolonged Exposure Therapy: A Systematic Review of the Literature.

Per the most recent census, non-Latinx White individuals comprise the majority of the U.S. population (76.6%); Latinx individuals make up 18.3% of the total U.S. population, followed by African Americans (13.4%) and Asians (5.9%). Given the high prevalence rates of posttraumatic stress disorder (PTSD) observed across many ethnoracial minority groups in the United States, the fact that PTSD presentation may vary across culture, and the National Institute of Health's mandates for the inclusion of women and minorities in clinical outcome research, the aim of the present systematic review was to examine minority inclusion in clinical outcome research for PTSD. Our review focused exclusively on one empirically supported treatment: prolonged exposure therapy (PE); we identified 38 studies that met the inclusion criteria. Apart from African Americans, who were overrepresented in 21 studies (inclusion rate range: 13.5%-73.9%), ethnoracial minority inclusion in RCTs examining PE was low. More specifically, across included studies that reported ethnoracial minority data, 58.9% of participants were White, 31.1% were African American, 4.9% were Latinx, 0.6% were Asian American or Pacific Islander, and 4.7% reported race as "other." Inclusion rates for ethnoracial minorities appeared to increase across time, and recruitment strategies did not appear to be associated with increased ethnoracial minority participation in RCTs for PE.

Recent and remote retrograde memory deficit in rats with medial entorhinal cortex lesions.

The hippocampus is critically involved in the acquisition and retrieval of spatial memories. Even though some memories become independent of the hippocampus over time, expression of spatial memories have consistently been found to permanently depend on the hippocampus. Recent studies have focused on the adjacent medial entorhinal cortex (MEC), as it provides major projections to the hippocampus. These studies have shown that lesions of the MEC disrupt spatial processing in the hippocampus and impair spatial memory acquisition on the watermaze task. MEC lesions acquired after learning the watermaze task also disrupt recently acquired spatial memories. However, the effect of MEC lesions on remotely acquired memories is unknown. The current study examined the effect of MEC lesions on recent and remote memory retrieval using three hippocampus-dependent tasks: the watermaze, trace fear conditioning, and novel object recognition. MEC lesions caused impaired retrieval of recently and remotely acquired memory for the watermaze. Rats with MEC lesions also showed impaired fear memory when exposed to the previously conditioned context or the associated tone, and this reduction was seen both when the lesion occurred soon after trace fear condition and when it occurred a month after conditioning. In contrast, MEC lesions did not disrupt novel object recognition. These findings indicate that even with an intact hippocampus, rats with MEC lesions cannot retrieve recent or remote spatial memories. In addition, the involvement of the MEC in memory extends beyond is role in navigation and place memory.

Neuronal UCP1 expression suggests a mechanism for local thermogenesis during hibernation.

Hibernating mammals possess a unique ability to reduce their body temperature to ambient levels, which can be as low as -2.9 °C, by active down-regulation of metabolism. Despite such a depressed physiologic phenotype, hibernators still maintain activity in their nervous systems, as evidenced by their continued sensitivity to auditory, tactile, and thermal stimulation. The molecular mechanisms that underlie this adaptation remain unknown. We report, using differential transcriptomics alongside immunohistologic and biochemical analyses, that neurons from thirteen-lined ground squirrels (Ictidomys tridecemlineatus) express mitochondrial uncoupling protein 1 (UCP1). The expression changes seasonally, with higher expression during hibernation compared with the summer active state. Functional and pharmacologic analyses show that squirrel UCP1 acts as the typical thermogenic protein in vitro. Accordingly, we found that mitochondria isolated from torpid squirrel brain show a high level of palmitate-induced uncoupling. Furthermore, torpid squirrels during the hibernation season keep their brain temperature significantly elevated above ambient temperature and that of the rest of the body, including brown adipose tissue. Together, our findings suggest that UCP1 contributes to local thermogenesis in the squirrel brain, and thus supports nervous tissue function at low body temperature during hibernation.

Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl.

Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents.

Consolidation of spatial memory in the rat: Findings using zeta-inhibitory peptide.

Whether or not spatial memories reorganize in the rodent brain is an unanswered question that carries the importance of whether the rodent provides a suitable animal model of human retrograde amnesia. The finding of equally impaired recent and remote spatial memory could reflect the continued importance of the hippocampus for spatial memory or a performance deficit (for example, hippocampal lesions may impair the rat's ability to use distal spatial cues to navigate to a specific point in space). In the current study, we tested recent and remote spatial memory in rats following hippocampal ZIP (zeta-pseudosubstrate inhibitory peptide) infusion to inhibit PKMzeta. Hippocampal ZIP infusion has previously been shown to impair spatial and nonspatial memory soon after learning, presumably by reversing late-phase long-term potentiation, allowing us to disrupt memory without damaging hippocampal tissue. We used a stereotaxic approach for infusing ZIP throughout the dorsal, intermediate, and ventral hippocampus following spatial memory training. Although rats showed intact memory retrieval on the standard Morris watermaze task and trace fear conditioning, rats infused with ZIP 24h after training on the annular watermaze task exhibited impaired spatial memory compared to control rats (those infused with aCSF) and performed no different than chance. In contrast, rats infused with ZIP 1month after training performed similar to control rats and both groups performed above chance. Additionally, the ability to form new memories after ZIP infusions remained intact. Thus, ZIP infusions into the hippocampus after learning impaired retrieval of recently formed spatial memories while sparing remote spatial memories.

Hippocampus, perirhinal cortex, and complex visual discriminations in rats and humans.

Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Notably, rats with hippocampal lesions exhibited the same impairment. Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. Both lesion groups were able to acquire visual discriminations involving the same objects used in the oddity task. Patients with hippocampal damage or larger medial temporal lobe lesions were intact in a similar oddity task that allowed participants to explore objects quickly using eye movements. We suggest that humans were able to rely on an intact working memory capacity to perform this task, whereas rats (who moved slowly among the objects) needed to rely on long-term memory.

Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species.

Sex pheromone communication, acting as a prezygotic barrier to mating, is believed to have contributed to the speciation of moths and butterflies in the order Lepidoptera. Five decades after the discovery of the first moth sex pheromone, little is known about the molecular mechanisms that underlie the evolution of pheromone communication between closely related species. Although Asian and European corn borers (ACB and ECB) can be interbred in the laboratory, they are behaviorally isolated from mating naturally by their responses to subtly different sex pheromone isomers, (E)-12- and (Z)-12-tetradecenyl acetate and (E)-11- and (Z)-11-tetradecenyl acetate (ACB: E12, Z12; ECB; E11, Z11). Male moth olfactory systems respond specifically to the pheromone blend produced by their conspecific females. In vitro, ECB(Z) odorant receptor 3 (OR3), a sex pheromone receptor expressed in male antennae, responds strongly to E11 but also generally to the Z11, E12, and Z12 pheromones. In contrast, we show that ACB OR3, a gene that has been subjected to positive selection (ω = 2.9), responds preferentially to the ACB E12 and Z12 pheromones. In Ostrinia species the amino acid residue corresponding to position 148 in transmembrane domain 3 of OR3 is alanine (A), except for ACB OR3 that has a threonine (T) in this position. Mutation of this residue from A to T alters the pheromone recognition pattern by selectively reducing the E11 response ∼14-fold. These results suggest that discrete mutations that narrow the specificity of more broadly responsive sex pheromone receptors may provide a mechanism that contributes to speciation.

Hippocampal Infusion of Zeta Inhibitory Peptide Impairs Recent, but Not Remote, Recognition Memory in Rats.

Spatial memory in rodents can be erased following the infusion of zeta inhibitory peptide (ZIP) into the dorsal hippocampus via indwelling guide cannulas. It is believed that ZIP impairs spatial memory by reversing established late-phase long-term potentiation (LTP). However, it is unclear whether other forms of hippocampus-dependent memory, such as recognition memory, are also supported by hippocampal LTP. In the current study, we tested recognition memory in rats following hippocampal ZIP infusion. In order to combat the limited targeting of infusions via cannula, we implemented a stereotaxic approach for infusing ZIP throughout the dorsal, intermediate, and ventral hippocampus. Rats infused with ZIP 3-7 days after training on the novel object recognition task exhibited impaired object recognition memory compared to control rats (those infused with aCSF). In contrast, rats infused with ZIP 1 month after training performed similar to control rats. The ability to form new memories after ZIP infusions remained intact. We suggest that enhanced recognition memory for recent events is supported by hippocampal LTP, which can be reversed by hippocampal ZIP infusion.

Contribution of the medial entorhinal cortex to performance on the Traveling Salesperson Problem in rats.

In order to successfully navigate through space, animals must rely on multiple cognitive processes, including orientation in space, memory of object locations, and navigational decisions based on that information. Although highly-controlled behavioral tasks are valuable for isolating and targeting specific processes, they risk producing a narrow understanding of complex behavior in natural contexts. The Traveling Salesperson Problem (TSP) is an optimization problem that can be used to study naturalistic foraging behaviors, in which subjects select routes between multiple baited targets. Foraging is a spontaneous, yet complex, behavior, involving decision-making, attention, course planning, and memory. Previous research found that hippocampal lesions in rats impaired TSP task performance, particularly on measures of spatial memory. Although traditional laboratory tests have shown the medial entorhinal cortex (MEC) to play an important role in spatial memory, if and how the MEC is involved in finding efficient solutions to the TSP remains unknown. In the current study, rats were trained on the TSP, learning to retrieve bait from targets in a variety of spatial configurations. After recovering from either an MEC lesion or control sham surgery, the rats were tested on eight new configurations. Our results showed that, similar to rats with hippocampal lesions, MEC-lesioned rats were impaired on measures of spatial memory, but not spatial decision-making, with greatest impairments on configurations requiring a global navigational strategy for selecting the optimal route. These findings suggest that the MEC is important for effective spatial navigation, especially when global cue processing is required.

Memory deficits and hippocampal cytokine expression in a rat model of ADHD.

Attention-deficit/hyperactivity disorder (ADHD) is a complex behavioral disorder characterized by hyperactivity, impulsivity, inattention, and deficits in working memory and time perception. While animal models have advanced our neurobiological understanding of this condition, there are limited and inconsistent data on working and elapsed time memory function. Inflammatory signaling has been identified as a key factor in memory and cognitive impairments, but its role in ADHD remains unclear. Additionally, the disproportionate investigation of male subjects in ADHD research has contributed to a poor understanding of the disorder in females. This study sought to investigate the potential connections between memory, neuroimmunology, and ADHD in both male and female animals. Specifically, we utilized the spontaneously hypertensive rat (SHR), one of the most extensively studied animal models of ADHD. Compared to their control, the Wistar-Kyoto (WKY) rat, male SHR are reported to exhibit several behavioral phenotypes associated with ADHD, including hyperactivity, impulsivity, and poor sustained attention, along with impairments in learning and memory. As the hippocampus is a key brain region for learning and memory, we examined the behavior of male and female SHR and WKY rats in two hippocampal-dependent memory tasks. Our findings revealed that SHR have delay-dependent working memory deficits that were similar to, albeit less severe than, those seen in hippocampal-lesioned rats. We also observed impairments in elapsed time processing in female SHR, particularly in the discrimination of longer time durations. To investigate the impact of inflammatory signaling on memory in these rats, we analyzed the levels of several cytokines in the dorsal and ventral hippocampus of SHR and WKY. Although we found some sex and genotype differences, concentrations were generally similar between groups. Taken together, our results indicate that SHR exhibit deficits in spatial working memory and memory for elapsed time, as well as some differences in hippocampal cytokine concentrations. These findings contribute to a better understanding of the neurobiological basis of ADHD in both sexes and may inform future research aimed at developing effective treatments for the disorder. Nonetheless, the potential mediating role of neuroinflammation in the memory symptomatology of SHR requires further investigation.

Law enforcement mental health: A systematic review of qualitative research.

The aim of this review was to explore qualitative accounts of law enforcement (LE) officers' personal experiences of mental health, in terms of linguistic descriptions, relationships between occupational experiences and mental health, and challenges to maintaining mental well-being. Using preferred reporting items for systematic reviews and meta-analyses guidelines, 1,876 articles were screened, and 31 studies were included in the current review. A risk of bias assessment was used to assess the study's methodological rigor, and data were extracted to answer three exploratory research questions. Results revealed that LE officers frequently experience occupational stressors and identify different mental health difficulties as a result. Additionally, cultural norms and stigma prevalent in the LE profession were noted to contribute to experiences of mental health and impact LE officers' ability to reach out for help and utilize professional resources. This review suggests that efforts to offer mental health services to LE officers need to prioritize cultural competence, confidentiality, and education to overcome stigma and increase mental health literacy and service use. Stakeholders addressing the LE mental health crisis may find this review useful due to several practical recommendations offered. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The path to memory is guided by strategy: distinct networks are engaged in associative encoding under visual and verbal strategy and influence memory performance in healthy and impaired individuals.

Given the diversity of stimuli encountered in daily life, a variety of strategies must be used for learning new information. Relating and encoding visual and verbal stimuli into memory has been probed using various tasks and stimulus types. Engagement of specific subsequent memory and cortical processing regions depends on the stimulus modality of studied material; however, it remains unclear whether different encoding strategies similarly influence regional activity when stimulus type is held constant. In this study, participants encoded object pairs using a visual or verbal associative strategy during fMRI, and subsequent memory was assessed for pairs encoded under each strategy. Each strategy elicited distinct regional processing and subsequent memory effects: middle/superior frontal, lateral parietal, and lateral occipital for visually associated pairs and inferior frontal, medial frontal, and medial occipital for verbally associated pairs. This regional selectivity mimics the effects of stimulus modality, suggesting that cortical involvement in associative encoding is driven by strategy and not simply by stimulus type. The clinical relevance of these findings, probed in a patient with a recent aphasic stroke, suggest that training with strategies utilizing unaffected cortical regions might improve memory ability in patients with brain damage.

Breaking the silence: A qualitative analysis of trauma narratives submitted online by first responders.

OBJECTIVE: Trauma narration is important to PTSD recovery and is widely used in clinical interventions. First responders experience high rates of exposure to trauma yet there are no studies with a primarily first responder population despite that trauma exposure is a chronic and unavoidable aspect of their occupation. The aim of the current study was to qualitatively examine trauma narratives posted online through a supportive website dedicated for first responders. METHOD: 30 trauma narratives of police officers, firefighters, and emergency medical personnel were randomly chosen for inclusion in the study. While some narrative posters remained somewhat anonymous, overall, there was moderate diversity in terms of age, sex, job field, number of years on the job, and the locations of the employer. RESULTS: Online narration offered a less formalized opportunity for self-disclosure that allowed for authenticity, honesty, and vulnerability. Thematic analyses revealed 5 themes: idealization with the job, disillusionment with the job, on the job trauma, trauma sequalae, and coping with trauma. CONCLUSION: Findings suggest that first responders are exposed to trauma on the job that significantly alters their work and home lives. Although they experience psychopathology, and could benefit from formal treatment, their decision to seek treatment is impacted by stigma in the culture. Implications and future directions are discussed regarding the need to improve perceived connectedness and support and reduce stigma in online platforms and within the subculture to encourage healing. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Work-related traumatic stress spillover in first responder families: A systematic review of the literature.

OBJECTIVE: The aim of the current review was to examine the impact of trauma exposure on first responder families, particularly, in terms of their relationships, family roles and obligations, and engagement in risk factors. METHOD: Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRIMSA) guidelines, 3,213 articles were screened, and 16 studies met inclusion for the current review. A risk of bias assessment was conducted to determine the methodological rigor of included studies and data was extracted to highlight the research questions, targeted populations, study design, measurement instruments, and outcomes of the included studies. RESULTS: The majority of research questions were asked to understand the experience of being a spouse to a first responder and to identify the stressors, supports, and resources of first responders and their families. Additionally, studies in this area were determined to be conducted primarily with spouses or partners of first responders, utilizing predominantley cross-sectional methodologies and measurement instruments with good psychometric properties. CONCLUSIONS: A discussion of the limitations and gaps in the literature was included and generally highlighted a lack of diversity in sample demographic characteristics and study design. Five concrete recommendations for future research were made to address limitations and strengthen research in this area. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Mechanisms associated with the rapid decline in sea ice cover around a stranded ship in the Lazarev Sea, Antarctica.

In the satellite data era starting from 1979, the extent of Antarctic sea ice increased moderately for the first 37 years. However, the extent decreased to record low levels from 2016 to 2020, with the drop being greatest in the Weddell and Lazarev Seas of the Southern Ocean. An important question for the scientific fraternity and policymakers is to understand what ocean-atmospheric processes triggered such a rapid decline in sea ice. We employ in-situ, satellite, and atmospheric reanalysis data to examine the causative mechanism of anomalous sea ice variability in the Lazarev Sea at a time of ice growth in the annual cycle (March-April 2019), when a cargo ship was stuck in extensive ice cover and freed following the unusual decline in sea ice. High-resolution Sentinel-1 synthetic aperture radar captured a distinct view of the ship location and track within extensive ice cover of fast sea ice, dense pack ice, and icebergs in the Lazarev Sea on 27 March 2019. Subsequently, the sea ice cover declined and reached the fourth lowest extent in the entire satellite record during April 2019 which was 25.6% lower than the long-term mean value of 2.65 × 106 km2. We show that the anomalous sea ice variability was due to the occurrence of eastward-moving polar cyclones, including a quasi-stationary explosive development that impacted sea ice through extreme changes in ocean-atmospheric conditions. The cyclone-induced dynamic (poleward propagation of ocean waves and ice motion) and thermodynamic (heat and moisture plumes from midlatitudes, ocean mixed layer warming) processes coupled with high tides provided a conducive environment for an exceptional decline in sea ice over the region of ship movement.