Impact of pandemic-related movement restriction on public access defibrillation in Japan: a retrospective cohort study

OBJECTIVES

To analyse monthly changes in public access defibrillation (PAD) incidence and outcomes of out-of-hospital cardiac arrest (OHCA) during the 2020-2021 COVID-19 pandemic compared with those during the 2016-2019 prepandemic period with consideration of pandemic-related movement restriction.

DESIGN

Retrospective cohort study.

SETTING

An extended database was created by combining and reconciling the nationwide Utstein-style OHCA and the emergency medical service (EMS) transportation databases in Japan.

PARTICIPANTS

We analysed 226 182 EMS-witnessed, non-newborn and out-of-home OHCA cases in Japan.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were the PAD incidence and neurologically favourable 1-month survival rate. The secondary outcomes were bystander cardiopulmonary resuscitation (CPR) provision and dispatcher-assisted CPR attempts.

RESULTS

The proportion of out-of-home OHCA cases slightly decreased during the pandemic (from 33.7% to 31.9%). Although the pandemic was associated with a decreased PAD incidence, 2-year trend analyses by an interaction test showed that the PAD incidence was lower during the first nationwide declaration of a state of emergency (p<0.001) and in the pandemic's second year (p<0.01). Regardless of location, delays in basic life support (BLS) actions and EMS contact with patients were more common and the rate of PAD-induced return of spontaneous circulation was lower during the pandemic. PAD incidence reduction was significant only in locations with a recommendation of automated external defibrillator placement (p<0.001). In other locations, a pronounced delay in BLS was found during the pandemic. The neurologically favourable survival rate was reduced in parallel with the reduced PAD incidence during the pandemic (r=0.612, p=0.002).

CONCLUSIONS

Prolonged and repeated movement restrictions during the COVID-19 pandemic worsened the OHCA outcomes concurrently with disturbed BLS actions, including the reduced PAD incidence in out-of-home settings. Maintaining BLS training, re-arranging automated external defibrillator placement and establishing a local alert system for recruiting well-trained citizens to the scene are essential.

Deficiency of mastl, a mitotic regulator, results in cell detachment from developing tissues of zebrafish embryos

To form tissues with unique functions and structures, it is important that the cells that comprise them maintain physical contact. On the other hand, with each mitosis, drastic changes in cell shapes, cell adhesion, and cytoskeletal architecture may cause such contacts to be temporarily weakened, risking improper development and maintenance of tissues. Despite such risks, tissues form properly during normal development. However, it is not well understood whether mitotic abnormalities affect tissue formation. Here, analysis of zebrafish embryos with aberrant mitosis shows that proper progression of mitosis is important to maintain cell contact in developing tissues. By screening mutants with abnormal trunk and tail development, we obtained a mutant with perturbed expression of some tissue-specific genes in embryonic caudal regions. The responsible gene is mastl/gwl, which is involved in progression of mitosis. Analysis focusing on the chordo-neural hinge (CNH), the primordium of axial tissues, shows that cell detachment from the CNH is increased in mastl mutant embryos. Time-lapse imaging reveals that this cell detachment occurs during mitosis. These results suggest that cells are unable to maintain contact due to abnormalities in progression of mitosis in mastl mutants.

Structure-based engineering of Tor complexes reveals that two types of yeast TORC1 produce distinct phenotypes

Certain proteins assemble into diverse complex states, each having a distinct and unique function in the cell. Target of rapamycin (Tor) complex 1 (TORC1) plays a central role in signalling pathways that allow cells to respond to the environment, including nutritional status signalling. TORC1 is widely recognised for its association with various diseases. The budding yeast Saccharomyces cerevisiae has two types of TORC1, Tor1-containing TORC1 and Tor2-containing TORC1, which comprise different constituent proteins but are considered to have the same function. Here, we computationally modelled the relevant complex structures and then, based on the structures, rationally engineered a Tor2 mutant that could form Tor complex 2 (TORC2) but not TORC1, resulting in a redesign of the complex states. Functional analysis of the Tor2 mutant revealed that the two types of TORC1 induce different phenotypes, with changes observed in rapamycin, caffeine and pH dependencies of cell growth, as well as in replicative and chronological lifespan. These findings uncovered by a general approach with huge potential - model structure-based engineering - are expected to provide further insights into various fields such as molecular evolution and lifespan.

Cellular responses to compound stress induced by atmospheric-pressure plasma in fission yeast

The stress response is one of the most fundamental cellular processes. Although the molecular mechanisms underlying responses to a single stressor have been extensively studied, cellular responses to multiple stresses remain largely unknown. Here, we characterized fission yeast cellular responses to a novel stress inducer, non-thermal atmospheric-pressure plasma. Plasma irradiation generates ultraviolet radiation, electromagnetic fields and a variety of chemically reactive species simultaneously, and thus can impose multiple stresses on cells. We applied direct plasma irradiation to fission yeast and showed that strong plasma irradiation inhibited fission yeast growth. We demonstrated that mutants lacking sep1 and ace2, both of which encode transcription factors required for proper cell separation, were resistant to plasma irradiation. Sep1-target transcripts were downregulated by mild plasma irradiation. We also demonstrated that plasma irradiation inhibited the target of rapamycin kinase complex 1 (TORC1). These observations indicate that two pathways, namely the Sep1-Ace2 cell separation pathway and TORC1 pathway, operate when fission yeast cope with multiple stresses induced by plasma irradiation.

ecl family genes: Factors linking starvation and lifespan extension in Schizosaccharomyces pombe

In the fission yeast Schizosaccharomyces pombe, the duration of survival in the stationary phase, termed the chronological lifespan (CLS), is affected by various environmental factors and the corresponding gene activities. The ecl family genes were identified in the genomic region encoding non-coding RNA as positive regulators of CLS in S. pombe, and subsequently shown to encode relatively short proteins. Several studies revealed that ecl family genes respond to various nutritional starvation conditions via different mechanisms, and they are additionally involved in stress resistance, autophagy, sexual differentiation, and cell cycle control. Recent studies reported that Ecl family proteins strongly suppress target of rapamycin complex 1, which is a conserved eukaryotic nutrient-sensing kinase complex that also regulates longevity in a variety of organisms. In this review, we introduce the regulatory mechanisms of Ecl family proteins and discuss their emerging findings.

Metarhizium robertsii COH1 functionally complements Schizosaccharomyces pombe Ecl family proteins

The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signals and induce appropriate intracellular responses, including the extension of chronological lifespan and induction of sexual differentiation. Herein, we propose that the colonization of hemocoel 1 (COH1) protein of Metarhizium robertsii, an insect-pathogenic fungus, is a functional homolog of S. pombe Ecl1 family proteins.

The physiological response during optogenetic-based cardiac pacing in awake freely moving mice

There are several methods to control a heart rate, such as electrical stimulation and drug administration. However, these methods may be invasive or affect other organs. Recently, an optogenetic-based cardiac pacing method has enabled us to stimulate the cardiac muscle in non-contact. In many previous studies, the pacing was applied ex vivo or in anesthetized animals. Therefore, the physiologic response of animals during optogenetic pacing remains unclear. Here, we established a method of optogenetic-based cardiac pacing in awake, freely moving mice and simultaneously measured electrocardiogram, blood pressure, and respiration. As a result, light-induced myocardial contraction produces blood flow and indirectly affects the respiration rhythm. Additionally, light illumination enabled heart rate recovery in bradycardic mice. These findings may be employed for further research that relates a heartbeat state to animal behavior. Together, this method may drive the development of less invasive pacemakers without pacing leads.

Endothelial Insulin Resistance Exacerbates Experimental Periodontitis

Epidemiological studies suggest that the severity of periodontitis is higher in people with diabetes than in healthy individuals. Insulin resistance might play a crucial role in the pathogenesis of multiple diabetic complications and is reportedly induced in the gingiva of rodents with type 2 diabetes; however, the molecular mechanisms underlying the pathogenesis of diabetes-related periodontitis remain unclear. Therefore, we aimed to investigate whether endothelial insulin resistance in the gingiva may contribute to the pathogenesis of periodontitis as well as elucidate its underlying molecular mechanisms. We demonstrated that insulin treatment downregulated lipopolysaccharide (LPS)-induced or tumor necrosis factor α (TNFα)-induced VCAM1 expression in endothelial cells (ECs) via the PI3K/Akt activating pathway, resulting in reduced cellular adhesion between ECs and leukocytes. Hyperglycemia-induced selective insulin resistance in ECs diminished the effect of insulin on LPS- or TNFα-stimulated VCAM1 expression. Vascular endothelial cell-specific insulin receptor knockout (VEIRKO) mice exhibited selective inhibition of the PI3K/Akt pathway in the gingiva and advanced experimental periodontitis-induced alveolar bone loss via upregulation of Vcam1, Tnfα, Mcp-1, Rankl, and neutrophil migration into the gingiva compared with that in the wild-type (WT) mice despite being free from diabetes. We also observed that insulin-mediated activation of FoxO1, a downstream target of Akt, was suppressed in the gingiva of VEIRKO and high-fat diet (HFD)-fed mice, hyperglycemia-treated ECs, and primary ECs from VEIRKO. Further analysis using ECs transfected with intact and mutated FoxO1, with mutations at 3 insulin-mediated phosphorylation sites (T24A, S256D, S316A), suggested that insulin-mediated regulation of VCAM1 expression and cellular adhesion of ECs with leukocytes was attenuated by mutated FoxO1 overexpression. These results suggest that insulin resistance in ECs may contribute to the progression of periodontitis via dysregulated VCAM1 expression and cellular adhesion with leukocytes, resulting from reduced activation of the PI3K/Akt/FoxO1 axis.

Peripheral vs. Core Body Temperature as Hypocretin/Orexin Neurons Degenerate: Exercise Mitigates Increased Heat Loss

Hypocretins/Orexins (Hcrt/Ox) are hypothalamic neuropeptides implicated in diverse functions, including body temperature regulation through modulation of sympathetic vasoconstrictor tone. In the current study, we measured subcutaneous (T_sc) and core (T_b) body temperature as well as activity in a conditional transgenic mouse strain that allows the inducible ablation of Hcrt/Ox-containing neurons by removal of doxycycline (DOX) from their diet (orexin-DTA mice). Measurements were made during a baseline, when mice were being maintained on food containing DOX, and over 42 days while the mice were fed normal chow which resulted in Hcrt/Ox neuron degeneration. The home cages of the orexin-DTA mice were equipped with running wheels that were either locked or unlocked. In the presence of a locked running wheel, T_sc progressively decreased on days 28 and 42 in the DOX(-) condition, primarily during the dark phase (the major active period for rodents). This nocturnal reduction in T_sc was mitigated when mice had access to unlocked running wheels. In contrast to T_sc, T_b was largely maintained until day 42 in the DOX(-) condition even when the running wheel was locked. Acute changes in both T_sc and T_b were observed preceding, during, and following cataplexy. Our results suggest that ablation of Hcrt/Ox-containing neurons results in elevated heat loss, likely through reduced sympathetic vasoconstrictor tone, and that exercise may have some therapeutic benefit to patients with narcolepsy, a disorder caused by Hcrt/Ox deficiency. Acute changes in body temperature may facilitate prediction of cataplexy onset and lead to interventions to mitigate its occurrence.

ILF3 prion-like domain regulates gene expression and fear memory under chronic stress

The prion-like domain (PrLD) is a class of intrinsically disordered regions. Although its propensity to form condensates has been studied in the context of neurodegenerative diseases, the physiological role of PrLD remains unclear. Here, we investigated the role of PrLD in the RNA-binding protein NFAR2, generated by a splicing variant of the Ilf3 gene. Removal of the PrLD in mice did not impair the function of NFAR2 required for survival, but did affect the responses to chronic water immersion and restraint stress (WIRS). The PrLD was required for WIRS-sensitive nuclear localization of NFAR2 and WIRS-induced changes in mRNA expression and translation in the amygdala, a fear-related brain region. Consistently, the PrLD conferred resistance to WIRS in fear-associated memory formation. Our study provides insights into the PrLD-dependent role of NFAR2 for chronic stress adaptation in the brain.

The ecl family gene ecl3+ is induced by phosphate starvation and contributes to sexual differentiation in fission yeast

In Schizosaccharomyces pombe, ecl family genes are induced by several signals, such as starvation of various nutrients, including sulfur, amino acids and Mg2+, and environmental stress, including heat or oxidative stress. These genes mediate appropriate cellular responses and contribute to the maintenance of cell viability and induction of sexual differentiation. Although this yeast has three ecl family genes with overlapping functions, any environmental conditions that induce ecl3+ remain unidentified. We demonstrate that ecl3+ is induced by phosphate starvation, similar to its chromosomally neighboring genes, pho1+ and pho84+, which respectively encode an extracellular acid phosphatase and an inorganic phosphate transporter. ecl3+ expression was induced by the transcription factor Pho7 and affected by the cyclin-dependent kinase (CDK)-activating kinase Csk1. Phosphate starvation induced G1 arrest and sexual differentiation via ecl family genes. Biochemical analyses suggested that this G1 arrest was mediated by the stabilization of the CDK inhibitor Rum1, which was dependent on ecl family genes. This study shows that ecl family genes are required for appropriate responses to phosphate starvation and provides novel insights into the diversity and similarity of starvation responses.

A force balance model for a cell size-dependent meiotic nuclear oscillation in fission yeast

Fission yeast undergoes premeiotic nuclear oscillation, which is dependent on microtubules and is driven by cytoplasmic dynein. Although the molecular mechanisms have been analyzed, how a robust oscillation is generated despite the dynamic behaviors of microtubules has yet to be elucidated. Here, we show that the oscillation exhibits cell length-dependent frequency and requires a balance between microtubule and viscous drag forces, as well as proper microtubule dynamics. Comparison of the oscillations observed in living cells with a simulation model based on microtubule dynamic instability reveals that the period of oscillation correlates with cell length. Genetic alterations that reduce cargo size suggest that the nuclear movement depends on viscous drag forces. Deletion of a gene encoding Kinesin-8 inhibits microtubule catastrophe at the cell cortex and results in perturbation of oscillation, indicating that nuclear movement also depends on microtubule dynamic instability. Our findings link numerical parameters from the simulation model with cellular functions required for generating the oscillation and provide a basis for understanding the physical properties of microtubule-dependent nuclear movements.

[Patient Radiation Dose for Percutaneous Coronary Intervention by Treatment Area: Dosimetry Using DRLs 2020]

PURPOSE

Skin injury in patients due to radiation exposure has been a complication in percutaneous coronary intervention (PCI) for a long time. To the best of our knowledge, there have been no reports comparing radiation dose by treatment area with diagnostic reference levels (DRLs) 2020, although the radiation dose varies by treatment area in PCI.

METHODS

In this study, the treatment areas were classified into four segments (i.e., AHA #1-3, AHA #4, AHA #5-10, and AHA #11-15), and each segment was compared with DRLs 2020. This retrospective study included 984 consecutive patients with single-vessel disease and non-chronic total occlusion. PCI was performed on a single device.

RESULTS

The median radiation dose was 1640.8 mGy, and the radiation dose for AHA #4 was 2732.0 mGy, which was significantly higher than the other treatment areas (p<0.001). In AHA #4, the radiation dose increased due to the heavy use of the left cranial view, and the patient background contributed to the increased lesion complexity. Therefore, it was challenging to evaluate AHA #4 and the other treatment areas with a uniform DRL value.

CONCLUSION

Establishing a subdivided index for each treatment area is crucial if DRLs are used as a reference during procedures and as a guide for dose optimization.

Epidemiology of out-of-hospital cardiac arrests caused by anaphylaxis and factors associated with outcomes: an observational study

OBJECTIVES

Describe the epidemiologic features of out-of-hospital cardiac arrest (OHCA) caused by anaphylaxis and identify outcome-associated factors.

DESIGN

Observational study.

SETTING

Data from the Japanese Fire and Disaster Management Agency database.

PARTICIPANTS

A total of 292 patients from 879 057 OHCA events between 2013 and 2019 with OHCA caused by anaphylaxis and for whom prehospital resuscitation was attempted were included in the analysis.

OUTCOME MEASURES

The incidence of anaphylaxis-induced OHCA, neurologically favourable 1-month survival, defined as cerebral performance category 1 or 2, and 1-month survival.

RESULTS

The proportion of OHCAs caused by anaphylaxis was high in non-elderly and male patients from July to September and during business hours. Bystander-witnessed (adjusted OR=4.43; 95% CI 1.84 to 10.7) and emergency medical service-witnessed events (adjusted OR=3.28; 95% CI 1.21 to 8.87) were associated with higher rates of neurologically favourable 1-month survival as well as better 1-month survival. Shockable initial ECG rhythms were recorded in only 19 patients (6.5%), and prehospital defibrillation was attempted in 16 such patients (84.2%). Neither shockable initial rhythms nor prehospital defibrillation was associated with better outcomes. Patients requiring advanced airway management had poor neurological outcomes (adjusted OR=0.17; 95% CI 0.07 to 0.42) and worse 1-month survival (adjusted OR=0.28; 95% CI 0.14 to 0.58).

CONCLUSIONS

Few cases of OHCA were attributable to anaphylaxis. Witnessed OHCAs, particularly those witnessed by bystanders, were associated with better neurological outcomes. Airway complications requiring advanced airway management were likely associated with poor outcomes.

Activity of putative orexin neurons during cataplexy

It is unclear why orexin-deficient animals, but not wild-type mice, show cataplexy. The current hypothesis predicts simultaneous excitation of cataplexy-inhibiting orexin neurons and cataplexy-inducing amygdala neurons. To test this hypothesis, we measured the activity of putative orexin neurons in orexin-knockout mice during cataplexy episodes using fiber photometry. We created two animal models of orexin-knockout mice with a GCaMP6 fluorescent indicator expressed in putative orexin neurons. We first prepared orexin-knockout mice crossed with transgenic mice carrying a tetracycline-controlled transactivator transgene under the control of the orexin promoter. TetO-GCaMP6 was then introduced into mice via an adeno-associated virus injection or natural crossing. The resulting two models showed restricted expression of GCaMP6 in the hypothalamus, where orexin neurons should be located, and showed excitation to an intruder stress that was similar to that observed in orexin-intact mice in our previous study. The activity of these putative orexin neurons increased immediately before the onset of cataplexy-like behavior but decreased (approximately − 20% of the baseline) during the cataplexy-like episode. We propose that the activity of orexin neurons during cataplexy is moderately inhibited by an unknown mechanism. The absence of cataplexy in wild-type mice may be explained by basal or residual activity-induced orexin release, and emotional stimulus-induced counter activation of orexin neurons may not be necessary. This study will serve as a basis for better treatment of cataplexy in narcolepsy patients.

Effect of large-scale disasters on bystander-initiated cardiopulmonary resuscitation in family-witnessed, friend-witnessed and colleague-witnessed out-of-hospital cardiac arrest: a retrospective analysis of prospectively collected, nationwide, population-based data

IMPORTANCE

The effect of large-scale disasters on bystander cardiopulmonary resuscitation (BCPR) performance is unknown.

OBJECTIVE

To investigate whether and how large-scale earthquake and tsunami as well as subsequent nuclear pollution influenced BCPR performance for out-of-hospital cardiac arrest (OHCA) witnessed by family and friends/colleagues.

DESIGN AND SETTING

Retrospective analysis of prospectively collected, nationwide, population-based data for OHCA cases.

PARTICIPANTS

From the nationwide OHCA registry recorded between 11 March 2010 and 1 March 2013, we extracted 74 684 family-witnessed and friend/colleague-witnessed OHCA cases without prehospital physician involvement.

EXPOSURE

Earthquake and tsunamis that were followed by nuclear pollution and largely affected the social life of citizens for at least 24 weeks.

MAIN OUTCOME AND MEASURE

Neurologically favourable outcome after 1 month, 1-month survival and BCPR.

METHODS

We analysed the 4-week average trend of BCPR rates in the years affected and before and after the disaster. We used univariate and multivariate logistic regression analyses to investigate whether these disasters affected BCPR and OHCA results.

RESULTS

Multivariable logistic regression for tsunami-affected prefectures revealed that the BCPR rate during the impact phase in 2011 was significantly lower than that in 2010/2012 (42.5% vs 48.2%; adjusted OR; 95% CI 0.82; 0.68 to 0.99). A lower level of bystander compliance with dispatcher-assisted CPR instructions (62.1% vs 69.5%, 0.72; 95% CI 0.57 to 0.92) in the presence of a preserved level of voluntary BCPR performance (23.6% vs 23.8%) was also observed. Both 1-month survival and neurologically favourable outcome rates during the impact phase in 2011 were significantly poorer than those in 2010/2012 (8.5% vs 10.7%, 0.72; 95% CI 0.52 to 0.99, 4.0% vs 5.2%, 0.62; 95% CI 0.38 to 0.98, respectively).

CONCLUSION AND RELEVANCE

A large-scale disaster with nuclear pollution influences BCPR performance and clinical outcomes of OHCA witnessed by family and friends/colleagues. Basic life-support training leading to voluntary-initiated BCPR might serve as preparedness for disaster and major accidents.

The dorsal hippocampal protein targeting to glycogen maintains ionotropic glutamate receptor subunits expression and contributes to working and short-term memories in mice

Brain glycogen metabolism is known to be involved in the learning and memory processes. Protein targeting to glycogen (PTG) is a crucial molecule for glycogenesis, and its expression level is shown to be increased in the dorsal hippocampus during fear memory acquisition and recall, suggesting that PTG may contribute to the memory process. However, its detailed role in the dorsal hippocampus remains unclear. Therefore, we knocked down the expression of PTG in the dorsal hippocampus and attempted to analyze its function behaviorally. PTG expression was found to be enriched in astrocytes. Furthermore, short hairpin RNA against PTG suppressed the expression of PTG in astrocytes. Mice with knockdown of PTG in the dorsal hippocampus showed suppressed alternation behavior in the Y-maze test and reduced memory recall at the first hour after acquisition in the passive avoidance test. Knockdown of mouse dorsal hippocampal astrocyte-specific PTG also impaired working memory in the Y-maze test. GluR1, GluR2, and NR2a subunits expressions were significantly down-regulated in the dorsal hippocampus of mice in which PTG was knocked down. These results indicate that PTG in the dorsal hippocampal astrocytes may contribute to working and short-term memories by maintaining the expression of glutamate receptor subunits.

Association between the types of bystander cardiopulmonary resuscitation and the survival with good neurologic outcome of preschool pediatric out-of-hospital cardiac arrest cases in Japan: A propensity score matching analysis using an extended nationwide database

BACKGROUND

Pediatric out-of-hospital cardiac arrests (OHCAs) are frequently associated with a respiratory etiology. Despite the high proportion of preschool children with OHCAs, very few studies on this special population exist. This study characterizes the epidemiologic features of preschool pediatric OHCAs and analyzes the advantage of conventional (ventilations with chest compressions) bystander cardiopulmonary resuscitation (CPR) over compression-only bystander CPR (BCPR) on the one-month post-event neurological status of the patient.

METHODS

Japanese nationwide databases for all ambulance transport events and OHCAs occurring during a 4-year period between 2016 and 2019 were combined, totalling 3,608 patient events. Children ≤6-years-old were included; physician- and EMS-witnessed events, no prehospital resuscitation effort events, and neonatal patient events were excluded. Neurologically favorable 1-month survival rates were compared among groups using univariate and multivariate analyses before and after propensity score matching.

RESULTS

From the combined database, 2,882 pediatric OHCAs meeting selection criteria were categorized as no BCPR (984), compression-only BCPR (1,428), and conventional BCPR (470). The proportion of bystander-witnessed cases was low (22.3%). Most OHCA witnesses were family members (88.5%), and most OHCAs occurred at home (88.0%). The neurologically favorable 1-month survival rates were: no BCPR 2.4%, compression only, 3.2%, and conventional 6.6% (P < 0.01). Multivariate logistic regression analysis before and after matching showed that conventional BCPR was associated with higher neurologically favorable 1-month survival than compression-only BCPR. Subgroup analyses after matching demonstrated that conventional BCPR was associated with better outcomes in nonmedical (adjusted odds ratio; 95% confidence interval, 2.83; 1.09-7.32) and unwitnessed OHCA cases (3.42; 1.09-10.8).

CONCLUSIONS

Conventional CPR is rarely performed by bystanders in preschool pediatric OHCA. However, conventional BCPR results in neurologically favorable outcomes in nonmedical and unwitnessed cases.

Involvement of A5/A7 noradrenergic neurons and B2 serotonergic neurons in nociceptive processing: a fiber photometry study

In the central nervous system, the A6 noradrenaline (NA) and the B3 serotonin (5-HT) cell groups are well-recognized players in the descending antinociceptive system, while other NA/5-HT cell groups are not well characterized. A5/A7 NA and B2 5-HT cells project to the spinal horn and form descending pathways. We recorded G-CaMP6 green fluorescence signal intensities in the A5/A7 NA and the B2 5-HT cell groups of awake mice in response to acute tail pinch stimuli, acute heat stimuli, and in the context of a non-noxious control test, using fiber photometry with a calcium imaging system. We first introduced G-CaMP6 in the A5/A7 NA or B2 5-HT neuronal soma, using transgenic mice carrying the tetracycline-controlled transactivator transgene under the control of either a dopamine β-hydroxylase or a tryptophan hydroxylase-2 promoters and by the site-specific injection of adeno-associated virus (AAV-TetO(3G)-G-CaMP6). After confirming the specific expression patterns of G-CaMP6, we recorded G-CaMP6 green fluorescence signals in these sites in awake mice in response to acute nociceptive stimuli. G-CaMP6 fluorescence intensity in the A5, A7, and B2 cell groups was rapidly increased in response to acute nociceptive stimuli and soon after, it returned to baseline fluorescence intensity. This was not observed in the non-noxious control test. The results indicate that acute nociceptive stimuli rapidly increase the activities of A5/A7 NA or B2 5-HT neurons but the non-noxious stimuli do not. The present study suggests that A5/A7 NA or B2 5-HT neurons play important roles in nociceptive processing in the central nervous system. We suggest that A5/A7/B2 neurons may be new therapeutic targets. All performed procedures were approved by the Institutional Animal Use Committee of Kagoshima University (MD17105) on February 22, 2018.

Aversive emotion rapidly activates orexin neurons and increases heart rate in freely moving mice

The perifornical area of the hypothalamus has been known as the center for the defense response, or fight-or-flight response, which is characterized by a concomitant rise in arterial blood pressure, heart rate, and respiratory frequency. It is well established that orexin neurons, which are located in this region, play a critical role in this response. In this study, we further examined this role by recording orexin neuronal activity and heart rate in freely moving mice using an original dual-channel fiber photometry system in vivo. Analysis of orexin neuron activity in relation to autonomic responses to aversive stimuli revealed a rapid increase in neuronal activity just prior to changes in heart rate. In addition, we examined whether orexin neurons would be activated by a conditioned neutral sound that was previously associated with aversive stimulus. We show that the memory of the aversive stimulus activated orexin neurons and increased heart rate. Our data suggest that orexin neurons are a key component linking aversive emotions to autonomic defense response. Our data also suggest that targeting orexin neurons may enable treatment of psychiatric disorders associated with chronic stress and traumatic memories.

Magnesium depletion extends fission yeast lifespan via general amino acid control activation

Nutrients including glucose, nitrogen, sulfur, zinc, and iron are involved in the regulation of chronological lifespan (CLS) of yeast, which serves as a model of the lifespan of differentiated cells of higher organisms. Herein, we show that magnesium (Mg²⁺) depletion extends CLS of the fission yeast Schizosaccharomyces pombe through a mechanism involving the Ecl1 gene family. We discovered that ecl1⁺ expression, which extends CLS, responds to Mg²⁺ depletion. Therefore, we investigated the underlying intracellular responses. In amino acid auxotrophic strains, Mg²⁺ depletion robustly induces ecl1⁺ expression through the activation of the general amino acid control (GAAC) pathway—the equivalent of the amino acid response of mammals. Polysome analysis indicated that the expression of Ecl1 family genes was required for regulating ribosome amount when cells were starved, suggesting that Ecl1 family gene products control the abundance of ribosomes, which contributes to longevity through the activation of the evolutionarily conserved GAAC pathway. The present study extends our understanding of the cellular response to Mg²⁺ depletion and its influence on the mechanism controlling longevity.

Dense Transposon Integration Reveals Essential Cleavage and Polyadenylation Factors Promote Heterochromatin Formation

Heterochromatin functions as a scaffold for factors responsible for gene silencing and chromosome segregation. Heterochromatin can be assembled by multiple pathways, including RNAi and RNA surveillance. We identified factors that form heterochromatin using dense profiles of transposable element integration in Schizosaccharomyces pombe. The candidates include a large number of essential proteins such as four canonical mRNA cleavage and polyadenylation factors. We find that Iss1, a subunit of the poly(A) polymerase module, plays a role in forming heterochromatin in centromere repeats that is independent of RNAi. Genome-wide maps reveal that Iss1 accumulates at genes regulated by RNA surveillance. Iss1 interacts with RNA surveillance factors Mmi1 and Rrp6, and importantly, Iss1 contributes to RNA elimination that forms heterochromatin at meiosis genes. Our profile of transposable element integration supports the model that a network of mRNA cleavage and polyadenylation factors coordinates RNA surveillance, including the mechanism that forms heterochromatin at meiotic genes.

Lee et al. use dense profiles of transposon integration to identify genes important for the formation of heterochromatin. Among many candidates, Iss1 is a canonical mRNA cleavage and polyadenylation factor found to be important for heterochromatin at meiotic genes by recruiting the nuclear exosome.

Patient outcomes of school-age, out-of-hospital cardiac arrest in Japan: A nationwide study of schoolchildren as witnesses

Aim

Using the data from the All‐Japan Utstein Registry, this study evaluates the neurologically favourable patient outcomes and associated factors of out‐of‐hospital cardiac arrest (OHCA) with Japanese schoolchildren as witnesses.

Methods

We analysed 1,068 school‐age children (6–18 years old) who underwent OHCA from 2011 to 2016. Among the 1,068 cases, 179 were witnessed by schoolchildren and 889 were witnessed by other bystanders. Propensity score‐matched and logistic regression analyses were used to evaluate the outcomes and associated factors.

Results

The crude neurologically favourable outcome in the schoolchildren‐witnessed group was considerably higher than that in the other‐bystander‐witnessed group (19.6% versus 12.3%; P < 0.010). However, the difference was not significant in the propensity score‐matched analysis (19.6% versus 21.8%; P = 0.602). The multivariable logistic regression analyses of school‐age OHCA with schoolchildren as witnesses demonstrated that bystander cardiopulmonary resuscitation (CPR) provision (odds ratio [OR] 4.12, 95% confidence interval [CI] 1.44–11.75), shockable initial rhythm (OR 3.39, 95% CI 1.43–8.04), and defibrillation (OR 4.58, 95% CI 1.65–12.71) provided by any bystander were positively associated with favourable outcomes. By contrast, dispatcher‐assisted CPR provision (OR 0.28, 95% CI 0.11–0.70), exogenous cause (OR 0.16, 95% CI 0.03–0.86), adrenaline administration (0.25; 95% CI 0.07–0.92), and prolonged response time (OR 0.86; 95% CI 0.75–0.98) were negatively associated with favourable outcomes.

Conclusions

Patient outcomes did not differ significantly between schoolchildren‐ and other‐bystander‐witnessed cases of school‐age OHCA. Although schoolchildren as witnesses might not be inferior to other bystanders in school‐age OHCA, further studies are needed to examine the effect of bystander CPR by schoolchildren and basic life support education in schools.

Novel Links between TORC1 and Traditional Non-Coding RNA, tRNA

Target of rapamycin (TOR) is a serine/threonine kinase that modulates cell growth and metabolism in response to environmental changes. Transfer RNA (tRNA) is an abundant and ubiquitous small non-coding RNA that is essential in the translation of mRNAs. Beyond its canonical role, it has been revealed that tRNAs have more diverse functions. TOR complex 1 (TORC1), which is one of the two TOR complexes, regulates tRNA synthesis by controlling RNA polymerase III. In addition to tRNA synthesis regulation, recent studies have revealed hidden connections between TORC1 and tRNA, which are both essential players in eukaryotic cellular activities. Here, we review the accumulating findings on the regulatory links between TORC1 and tRNA-particularly those links in the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe.

Involvement of A13 dopaminergic neurons located in the zona incerta in nociceptive processing: a fiber photometry study

The roles of serotonergic and noradrenergic signaling in nociceptive processing in the central nervous system are well known. However, dopaminergic signaling is also relevant to various physical functions, including nociception. The zona incerta is a subthalamic nucleus in which the A13 dopaminergic cell group resides, but how this A13 group affects nociceptive processing remains unknown. Recently, we showed that acute nociceptive stimuli rapidly induce the activity of A10 (ventral tegmental area) dopamine neurons via fiber photometry. In this study, we measured the activity of A13 dopaminergic neurons in response to acute nociceptive stimuli using the same system. Adeno-associated viruses (AAV-CAG-FLEX-G-CaMP6 and AAV-CAG-FLEX-mCherry) were unilaterally injected into the A13 site in transgenic mice carrying a dopamine transporter promotor-regulated Cre recombinase transgene to specifically introduce G-CaMP6/mCherry into A13 dopaminergic cell bodies through site-specific infection. We measured G-CaMP6/mCherry fluorescence intensity in the A13 site to acute nociceptive stimuli (pinch stimulus and heat stimulus). These stimuli significantly induced a rapid increase in G-CaMP6 fluorescence intensity, but non-nociceptive control stimuli did not. In contrast, mCherry fluorescence intensity was not significantly changed by nociceptive stimuli or non-nociceptive stimuli. Our finding is the first report to measure the activity of A13 dopaminergic neurons to aversive stimuli. A13 dopaminergic neurons project to the periaqueductal gray and the central nucleus of the amygdala, which are both well known as key regions in nociceptive processing. Therefore, together with our A10 study, our results indicate that A13 dopaminergic neurons play important roles in nociceptive processing.

Involvement of the Nucleus Accumbens in Chocolate-induced Cataplexy

Happiness is key for both mental and physical well-being. To further understand the brain mechanisms involved, we utilized the cataplexy that occurs in narcoleptic animal models as a quantitative behavioral measure because it is triggered by actions associated with happiness, such as laughter in humans and palatable foods in mice. Here we report that the rostral part of the nucleus accumbens (NAc) shell is strongly activated during the beginning of chocolate-induced cataplexy in orexin neuron-ablated mice. We made a local lesion in the NAc using ibotenic acid and observed the animals' behavior. The number of cataplexy bouts was negatively correlated to the lesion size. We also examined the hedonic response to palatable food by measuring the number of tongue protrusions in response to presentation of honey, which was also found to be negatively correlated to the lesion size. Next, we used clozapine N-oxide to either activate or inactivate the NAc through viral DREADD expression. As expected, the number of cataplexy bouts increased with activation and decreased with inactivation, and saline control injections showed no changes. Hedonic response in the DREADD experiment varied and showed both increases and decreases across mice. These results demonstrated that the rostral part of the NAc plays a crucial role in triggering cataplexy and hedonic orofacial movements. Since the NAc is also implicated in motivated behavior, we propose that the NAc is one of the key brain structures involved in happiness and is a driving force for positive emotion-related behaviors.

Prehospital Epinephrine as a Potential Factor Associated with Prehospital Rearrest

Objective: To investigate the impact of epinephrine on prehospital rearrest and re-attainment of prehospital return of spontaneous circulation (ROSC). Methods: Data for 9,292 (≥ 8 years) out-of-hospital cardiac arrest (OHCA) patients transported to hospitals by emergency medical services were collected in Ishikawa Prefecture, Japan during 2010-2018. Univariate and multivariable analyses were retrospectively performed for 1,163 patients with prehospital ROSC. Results: Of 1,163 patients, rearrest occurred in 272 (23.4%) but not in 891 (76.6%). Both single and multiple doses of epinephrine administered before prehospital ROSC (adjusted odds ratio (OR): 3.62, 95% confidence interval (CI): 2.42-5.46 for 1 mg, and 4.27, 2.58-6.79 for ≥ 2 mg) were main factors associated with rearrest. The association between initial and rearrest rhythms was significantly associated with epinephrine administration (p = 0.02). However, the rearrest rhythm was primarily associated with the initial rhythm (p < 0.01). The majority of patients with the non-shockable initial rhythm had pulseless electrical activity (PEA) as the rearrest rhythm, regardless of epinephrine administration (80.4% for administration, 81.6% for no administration). When the initial rhythm was shockable, the primary rearrest rhythms in patients with and without epinephrine administration before prehospital ROSC were PEA (52.2%) and ventricular fibrillation/pulseless ventricular tachycardia (56.8%), respectively. Only epinephrine administration after rearrest was associated with prehospital re-attainment of ROSC (adjusted OR: 2.49, 95% CI: 1.20-5.19). Stepwise multivariable logistic regression analyses revealed that neurologically favorable outcome was poorer in patients with rearrest than those without rearrest (9.9% vs. 25.0%, adjusted OR: 0.42, 95% CI: 0.23-0.73). The total prehospital doses of epinephrine were associated with poorer neurological outcome in a dose-dependent manner (adjusted OR: 0.22, 95% CI: 0.13-0.36 for 1 mg; 0.09, 0.04-0.19 for 2 mg; 0.03, 0.01-0.09 for ≥ 3 mg, no epinephrine as a reference). Transportation to hospitals with a unit for post-resuscitation care was associated with better neurological outcome (adjusted OR: 1.53, 95% CI: 1.02-2.32). Conclusions: The requirement for epinephrine administration before prehospital ROSC was associated with subsequent rearrest. Routine epinephrine administrations and rearrest were associated with poorer neurological outcome of OHCA patients with prehospital ROSC.

Involvement of supralemniscal nucleus (B9) 5-HT neuronal system in nociceptive processing: a fiber photometry study

Nociception is important perception that has harmful influence on daily life of humans. As to main pain management system, some descending pathways are called descending antinociceptive systems (DAS). As main pathways of DAS, it is well known that dorsal raphe (B6/B7) - rostral ventromedial medulla (B3) - spinal dorsal horn includes serotonergic system. However, possible role of supralemniscal (B9) serotonin (5-HT) cell group in pain management is still open question. In this study, we measured activities of B9 5-HT neuronal cell bodies and B9 5-HT neuron-derived axons located in the locus coeruleus (LC) and ventral tegmental area (VTA), which are also main players of pain management, using fiber photometry system. We introduced the G-CaMP6 in B9 5-HT neurons using transgenic mice carrying a tetracycline-controlled transactivator transgene (tTA) under the control of a tryptophan hydroxylase-2 (TPH2) promoter and site-specific injection of adeno associated virus (AAV-TetO(3G)-G-CaMP6). After confirmation of specific expression of G-CaMP6 in the target population, G-CaMP6 fluorescence intensity in B9 group and LC/VTA groups was measured in awake mice exposed to acute tail pinch and heat stimuli. G-CaMP6 fluorescence intensity rapidly increased by both stimuli in all groups, but not significantly reacted by nonnociceptive control stimuli. The present results clearly indicate that acute nociceptive stimuli cause a rapid increase in the activities of B9-LC/B9-VTA 5-HTergic pathways, suggesting that B9 5-HT neurons play important roles in nociceptive processing.

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping

BACKGROUND AND PURPOSE

Intraplaque hemorrhage in the carotid artery is related to an increased risk of cerebrovascular ischemic events. We aimed to investigate whether quantitative susceptibility mapping can characterize carotid artery plaque components and quantify the severity of intraplaque hemorrhage.

MATERIALS AND METHODS

For this ex vivo quantitative susceptibility mapping study, 9 carotid endarterectomy specimens were imaged on a 3T MR imaging scanner using a 3D multi-echo gradient-echo sequence and a microscopy coil. The samples were examined histologically using immunostains, including glycophorin A and Prussian blue. The areas of erythrocytes, iron deposits, calcification, and fibrous matrices observed on stained sections were compared with quantitative susceptibility mapping findings and their mean susceptibility values.

RESULTS

Intraplaque hemorrhage and iron deposits were observed only in areas hyperintense on quantitative susceptibility mapping; calcifications and fibrous matrices were prevalent in hypointense areas. The mean susceptibility values for necrotic cores with intraplaque hemorrhage but no iron deposits, cores with iron deposits but no intraplaque hemorrhage, cores without either intraplaque hemorrhage or iron deposits, and cores with calcification were 188 ± 51, 129 ± 49, -11 ± 17, and -158 ± 78 parts per billion, respectively. There was a significant difference in the mean susceptibility values among the 4 histologic components (P < .01). The mean susceptibility values of the whole plaque positively correlated with the percentage area positive for glycophorin A (r = 0.65, P < .001) and Prussian blue (r = 0.47, P < .001).

CONCLUSIONS

Our findings suggest that quantitative susceptibility mapping can characterize the composition of carotid plaques and quantify the degree of intraplaque hemorrhage and iron deposits.

Association of school hours with outcomes of out-of-hospital cardiac arrest in schoolchildren

Objective

To investigate the association of school hours with outcomes of schoolchildren with out-of-hospital cardiac arrest (OHCA).

Methods

From the 2005-2014 nationwide databases, we extracted the data for 1660 schoolchildren (6-17 years) with bystander-witnessed OHCA. Univariate analyses followed by propensity-matching procedures and stepwise logistic regression analyses were applied. School hours were defined as 08:00 to 18:00.

Results

The neurologically favourable 1-month survival rate during school hours was better than that during non-school hours only on school days: 18.4% and 10.5%, respectively. During school hours on school days, patients with OHCA more frequently received bystander cardiopulmonary resuscitation (CPR) and public access defibrillation (PAD), and had a shockable initial rhythm and presumed cardiac aetiology. The neurologically favourable 1-month survival rate did not significantly differ between school hours on school days and all other times of day after propensity score matching: 16.4% vs 16.1% (unadjusted OR 1.02; 95% CI 0.69 to 1.51). Stepwise logistic regression analysis during school hours on school days revealed that shockable initial rhythm (adjusted OR 2.44; 95% CI 1.12 to 5.42), PAD (adjusted OR 3.32; 95% CI 1.23 to 9.10), non-exogenous causes (adjusted OR 5.88; 95% CI 1.85 to 20.0) and a shorter emergency medical service (EMS) response time (adjusted OR 1.15; 95% CI 1.02 to 1.32) and witness-to-first CPR interval (adjusted OR 1.08; 95% CI 1.01 to 1.15) were major factors associated with an improved neurologically favourable 1-month survival rate.

Conclusions

School hours are not an independent factor associated with improved outcomes of OHCA in schoolchildren. The time delays in CPR and EMS arrival were independently associated with poor outcomes during school hours on school days.

Acute nociceptive stimuli rapidly induce the activity of serotonin and noradrenalin neurons in the brain stem of awake mice

Nociception is an important type of perception that has major influence on daily human life. There are some descending pathways related to pain management and modulation, which are collectively known as the descending antinociceptive system (DAS). Noradrenalin (NA) in the locus coeruleus (LC) and serotonin (5-HT) in the rostral ventromedial medulla (RVM) are components of the DAS. Most 5-HT neurons in the dorsal raphe (DR) have ascending projections rather than descending projections, and they project to the thalamus that modulates nociception. Both the DAS and the DR are believed to be involved in pain-emotion symptoms. In this study, we utilized a fiber photometry system to specifically examine the activity of LC NA neurons and RVM/DR 5-HT neurons using mice carrying tetracycline-controlled transactivator transgene (tTA) under the control of either a dopamine β-hydroxylase promoter or a tryptophan hydroxylase-2 promoter and site-specific infection of an adeno-associated virus carrying a TetO G-CaMP6 gene. After confirmation of specific expression of G-CaMP6 in the target populations, changes in green fluorescent signal intensity were recorded in awake mice upon exposure to acute nociceptive stimulation consisting of a pinch and application of heat (55 °C) to the tail. Both stimuli resulted in rapid and transient (<15 s) increases in the activity of LC NA neurons and RVM/DR 5-HT neurons while the control stimuli did not induce any changes. The present results clearly indicate that acute nociceptive stimuli increase the activity of LC NA neurons and RVM/DR 5 H T neurons and suggest a possible therapeutic target for pain treatment.

Proposal of patient-specific growth plate cartilage xenograft model for FGFR3 chondrodysplasia

OBJECTIVE

FGFR3 chondrodysplasia is caused by a gain-of-function mutation of the FGFR3 gene. The disease causes abnormal growth plate cartilage and lacks effective drug treatment. We sought to establish an in vivo model for the study of FGFR3 chondrodysplasia pathology and drug testing.

DESIGN

We created cartilage from human induced pluripotent stem cells (hiPSCs) and transplanted the cartilage into the subcutaneous spaces of immunodeficient mice. We then created cartilage from the hiPSCs of patients with FGFR3 chondrodysplasia and transplanted them into immunodeficient mice. We treated some mice with a FGFR inhibitor after the transplantation.

RESULTS

Xenografting the hiPSC-derived cartilage reproduced human growth plate cartilage consisting of zones of resting, proliferating, prehypertrophic and hypertrophic chondrocytes and bone in immunodeficient mice. Immunohistochemistry of xenografts using anti-human nuclear antigen antibody indicated that all chondrocytes in growth plate cartilage were human, whereas bone was composed of human and mouse cells. The pathology of small hypertrophic chondrocytes due to up-regulated FGFR3 signaling in FGFR3 skeletal dysplasia was recapitulated in growth plate cartilage formed in the xenografts of patient-specific hiPSC-derived cartilage. The mean diameters of hypertrophic chondrocytes between wild type and thanatophoric dysplasia were significantly different (95% CI: 13.2-26.9; n = 4 mice, one-way analysis of variance (ANOVA)). The pathology was corrected by systemic administration of a FGFR inhibitor to the mice.

CONCLUSION

The patient-specific growth plate cartilage xenograft model for FGFR3 skeletal dysplasia indicated recapitulation of pathology and effectiveness of a FGFR inhibitor for treatment and warrants more study for its usefulness to study disease pathology and drug testing.

Incidence of respiratory depression after epidural administration of morphine for cesarean delivery: findings using a continuous respiratory rate monitoring system

BACKGROUND

Epidural morphine is widely used for postoperative analgesia after cesarean delivery. However, respiratory depression can occur after neuraxial administration of morphine. Previous reports describing respiratory depression in obstetric patients have relied on intermittent visual counting of the respiratory rate. In this study, we estimated the incidence of respiratory depression in patients who had received epidural morphine after cesarean delivery, using a continuous respiratory rate monitoring system with a finger sensor.

METHODS

One hundred patients scheduled to undergo elective cesarean delivery and receive intraoperative neuraxial morphine between April and December 2016 were recruited for this single-center, prospective observational study. Postoperatively, all patients received epidural morphine 3 mg and were equipped with the Nellcor respiratory rate monitoring system. Respiratory depression was defined as both bradypnea (respiratory rate ≤10 breaths/min) and oxygen desaturation (mild ≤95%; moderate ≤90%; severe ≤85%) for longer than one minute. The number of patients with respiratory depression between administration of morphine and first ambulation was recorded hourly.

RESULTS

Complete monitoring was obtained for 89 of 100 women. The median duration of monitoring was 19.0 hours. Forty-six patients (52%) developed mild respiratory depression at least once before ambulation, but only one (1%) developed moderate respiratory depression. None required supplemental oxygen or naloxone.

CONCLUSIONS

Approximately half the women experienced mild respiratory depression, but only one developed moderate respiratory depression. Continuous respiratory rate monitoring until ambulation may assist in early identification of respiratory depression after neuraxial administration of morphine.

The Effects of KBT-3022, a New Anti-platelet Agent, on Hemorheological Properties in Guinea Pigs

Using guinea pigs, a study was conducted on the effects of KBT-3022, a new anti-platelet agent, on hemorheological properties in various tests including blood filterability, blood viscosity, shear stress-induced red blood cell (RBC) deformability and contents of ATP and 2,3-diphosphoglycerate (2,3-DPG). Oral administration of KBT-3022 at 1 and 10 mg/kg significantly increased blood filterability, and significantly reduced blood viscosity at 10 mg/kg without changing the hematocrit, plasma fibrinogen concentration or plasma viscosity. KBT-3022 (10 mg/kg, p.o.) improved RBC deformability in response to shear stress, which was evoked by passing the blood through a thin tube. This dose of KBT-3022 also increased the contents of ATP and 2,3-DPG in RBC. These findings indicate that KBT-3022 may reduce blood viscosity as a sequel to improvement of RBC deformability through direct action on RBC. The increase in the intracellular levels of ATP and 2,3-DPG was considered to be involved in this improvement of hemorheological properties. These hemorheological effects of KBT-3022 appear to be promising for the treatment of patients with ischemic vascular disease.

Acute Aversive Stimuli Rapidly Increase the Activity of Ventral Tegmental Area Dopamine Neurons in Awake Mice

The ventral tegmental area (VTA) is one of the origins of the brain dopaminergic system and is involved in regulating various physiological functions such as pain processing and motivation. In this study, we utilized a fiber photometry system to specifically investigate the activity of dopamine neurons in the VTA using dopamine transporter promoter-driven Cre recombinase-expressing mice and site-specific infection of adeno-associated virus carrying the FLEX G-CaMP6 gene. As expected, expression of G-CaMP6 was restricted to VTA dopamine neurons. We recorded G-CaMP6 green fluorescent signal, which reflected dopaminergic neuronal activity, in awake mice exposed to tail pinch, ultrasonic sound, predator odor, and a male intruder mouse. These stimuli resulted in a rapid and short-lasting increase in the activity of VTA dopamine neurons while the control stimuli of a gentle tail touch and appearance of empty box did not induce any changes. In addition, fluorescence intensity was not changed by any of these stimuli in the control animals expressing hrGFP instead of G-CaMP6 in VTA dopamine neurons. Our data clearly show that acute aversive stimuli rapidly increase the activity of VTA dopamine neurons and thus suggest a salience-processing role.

YTH-RNA-binding protein prevents deleterious expression of meiotic proteins by tethering their mRNAs to nuclear foci

Accurate and extensive regulation of meiotic gene expression is crucial to distinguish germ cells from somatic cells. In the fission yeast Schizosaccharomyces pombe, a YTH family RNA-binding protein, Mmi1, directs the nuclear exosome-mediated elimination of meiotic transcripts during vegetative proliferation. Mmi1 also induces the formation of facultative heterochromatin at a subset of its target genes. Here, we show that Mmi1 prevents the mistimed expression of meiotic proteins by tethering their mRNAs to the nuclear foci. Mmi1 interacts with itself with the assistance of a homolog of Enhancer of Rudimentary, Erh1. Mmi1 self-interaction is required for foci formation, target transcript elimination, their nuclear retention, and protein expression inhibition. We propose that nuclear foci formed by Mmi1 are not only the site of RNA degradation, but also of sequestration of meiotic transcripts from the translation machinery.

Clarification of muscle synergy structure during standing-up motion of healthy young, elderly and post-stroke patients

Standing-up motion is an important daily activity. It has been known that elderly and post-stroke patients have difficulty in performing standing-up motion. The standing-up motion is retrained by therapists to maximize independence of the elderly and post-stroke patients, but it is not clear how the elderly and post-stroke patients control their redundant muscles to achieve standing-up motion. This study employed the concept of muscle synergy to analyze how healthy young adults, healthy elderly people and post-stroke patients control their muscles. Experimental result verified that four muscle synergies can represent human standing-up motion. In addition, it indicated that the post-stroke patients shift the weights of muscle synergies to finish standing-up motion comparing to healthy subjects. Moreover, different muscle synergy structures were associated with the CoM and joint kinematics.

tRNA production links nutrient conditions to the onset of sexual differentiation through the TORC1 pathway

Target of rapamycin (TOR) kinase controls cell growth and metabolism in response to nutrient availability. In the fission yeast Schizosaccharomyces pombe, TOR complex 1 (TORC1) promotes vegetative growth and inhibits sexual differentiation in the presence of ample nutrients. Here, we report the isolation and characterization of mutants with similar phenotypes as TORC1 mutants, in that they initiate sexual differentiation even in nutrient-rich conditions. In most mutants identified, TORC1 activity is downregulated and the mutated genes are involved in tRNA expression or modification. Expression of tRNA precursors decreases when cells undergo sexual differentiation. Furthermore, overexpression of tRNA precursors prevents TORC1 downregulation upon nitrogen starvation and represses the initiation of sexual differentiation. Based on these observations, we propose that tRNA precursors operate in the S. pombe TORC1 pathway to switch growth mode from vegetative to reproductive.

Activation of ventral tegmental area dopaminergic neurons reverses pathological allodynia resulting from nerve injury or bone cancer

Chronic pain induced by nerve damage due to trauma or invasion of cancer to the bone elicits severe ongoing pain as well as hyperalgesia and allodynia likely reflecting adaptive changes within central circuits that amplify nociceptive signals. The present study explored the possible contribution of the mesolimbic dopaminergic circuit in promoting allodynia related to neuropathic and cancer pain. Mice with ligation of the sciatic nerve or treated with intrafemoral osteosarcoma cells showed allodynia to a thermal stimulus applied to the paw on the injured side. Patch clamp electrophysiology revealed that the intrinsic neuronal excitability of ventral tegmental area (VTA) dopamine neurons projecting to the nucleus accumbens (N.Acc.) was significantly reduced in those mice. We used tyrosine hydroxylase (TH)-cre mice that were microinjected with adeno-associated virus (AAV) to express channelrhodopsin-2 (ChR2) to allow optogenetic stimulation of VTA dopaminergic neurons in the VTA or in their N.Acc. terminals. Optogenetic activation of these cells produced a significant but transient anti-allodynic effect in nerve injured or tumor-bearing mice without increasing response thresholds to thermal stimulation in sham-operated animals. Suppressed activity of mesolimbic dopaminergic neurons is likely to contribute to decreased inhibition of N.Acc. output neurons and to neuropathic or cancer pain-induced allodynia suggesting strategies for modulation of pathological pain states.