Noradrenergic Regulation of the Medial Prefrontal Cortex Mediates Stress Coping in Postpartum Female Mice.

The prevalence of depression in women increases during the postpartum period. We previously reported that subchronic exposure to social stress decreased passive coping in postpartum female mice. This study aimed to investigate whether noradrenaline regulation might regulate coping styles in mice. We first determined whether a different type of stress, subchronic physical stress, decreases passive coping in postpartum females. Postpartum female, virgin female, and male mice were exposed to subchronic restraint stress (restraint stress for 4 h for 5 consecutive days). Subchronic restraint stress decreased passive coping in postpartum females but not in virgin females and males in the forced swim and tail suspension tests. We next examined the neuronal mechanism by which subchronic stress decreases passive coping in postpartum female mice. Neuronal activity and expression of noradrenergic receptors in the medial prefrontal cortex (mPFC) were analyzed using immunohistochemistry and reverse transcription-quantitative polymerase chain reaction, respectively. The mPFC was manipulated using chemogenetics, knockdown, or an α2A adrenergic receptor (AR) antagonist. Immunohistochemistry revealed that subchronic restraint stress increased glutamatergic neuron activation in the mPFC via forced swim stress and decreased α2A AR expression in postpartum females. Chemogenetic activation of glutamatergic neurons in the mPFC, knockdown of α2AAR in the mPFC, and the α2A AR receptor antagonist atipamezole treatment decreased passive coping in postpartum females. Subchronic restraint stress decreased passive coping in postpartum females by increasing glutamatergic neuron activity in the mPFC through α2A AR attenuation. The noradrenergic regulation of the mPFC may be a new target for treating postpartum depression.

Measurement of individual external doses of Tokyo Electric Power Company Holdings employees working in Fukushima Prefecture and the relationship between individual external doses and air dose rates in areas including difficult-to-return zones.

Since the Fukushima Daiichi Nuclear Power Station accident, evacuation orders have been lifted except for the difficult-to-return zones (DRZs). Within the DRZs, there has been designated a special zone for reconstruction and revitalisation (SZRR). Decontamination of the SZRR has been promoted so that evacuation orders may be lifted. Previous studies measured individual external doses in the evacuation order-lifted zones (ELZs) and other living areas where the annual additional individual external dose was overall less than approximately 5 mSv y-1. However, there have been few reports about the measurement of individual external doses in a SZRR or outside of an SZRR (O-SZRR). In SZRRs and O-SZRRs, Tokyo Electric Power Company Holdings employees work mainly outdoors. Therefore, the employees' individual external doses and air dose rates were measured in these zones from March 2020 through January 2021. Our key results were:The median (minimum to maximum) individual external doses at outdoor locations were 0.16µSv h-1(0.05-0.63µSv h-1), 0.57µSv h-1(0.15-3.92µSv h-1), and 1.36µSv h-1(0.14-11.91µSv h-1) for the ELZ, SZRR, and O-SZRR, respectively.The conversion coefficients for the air dose rate measured by airborne monitoring to individual external dose were 0.23, 0.38, and 0.50 for the ELZ, SZRR, and O-SZRR, respectively. The conversion coefficients were below 0.6, which was used in the national government model for estimating external exposure dose from air dose rate. In addition, the conversion coefficients for the SZRR and O-SZRR in air dose rates of less than 1.5µSv h-1differed from those obtained for the entire measurement range of this study.The conversion coefficient from air dose rate at a height of 1 m above ground level to individual external dose was researched across a broader and higher range of air dose rates than in the previous study (0.24-20.89µSv h-1). The conversion coefficient is confirmed to be 0.7, similar to previous studies.

Locus Coeruleus-Noradrenergic Neurons Regulate Stress Coping During Subchronic Exposure to Social Threats: A Characteristic Feature in Postpartum Female Mice.

Stress-coping strategies have been implicated in depression. The control of stress coping may improve the symptom and higher prevalence of depression during the postpartum period in women. However, the neuronal mechanisms underlying stress coping remain to be fully elucidated in postpartum women. In this study, we examined how locus coeruleus-noradrenergic (LC-NA) neurons, which have been associated with both stress coping and depression, regulate changes in coping style induced by subchronic exposure to unfamiliar male mice as a social threat in postpartum female mice. In contrast to virgin females, dams exposed to unfamiliar males daily for four consecutive days showed reduced immobility duration in the forced swim test, indicating that exposure to unfamiliar males decreased passive stress coping in dams. Exposure to unfamiliar males also decreased sucrose palatability in the sucrose preference test and suppressed the crouching behavior in the maternal care test but did not affect anxiety-like behavior in the hole-board test in dams. In fiber photometry analyses, LC-NA neurons showed differential activity between dams and virgin females in response to unfamiliar males. Chemogenetic inhibition of LC-NA neurons during exposure to unfamiliar males prevented the social threat-induced decrease in immobility duration in the forced swim test in dams. Furthermore, inhibition or activation of LC-NA neurons exacerbated crouching behavior in dams. These results indicate that LC-NA neurons regulate the social threat-induced decrease in passive stress coping and relieve social threat-induced inhibition of maternal care in postpartum female mice.

Comparative analysis on characteristics of two activated partial thromboplastin time reagents.

BACKGROUND: For the lack of standardized activated partial thromboplastin time (APTT), it has been pointed out that there are differences in values among several reagents. Recently, we have performed a parallel measurement on two reagents, Thrombocheck APTT-SLA and Coagpia APTT-n, and resulted with some dissociated samples. The purpose of this study is to clarify the possible factors related to ΔAPTT, the difference in measured values between the two reagents. MATERIALS AND METHODS: In order to clarify the factors related to ΔAPTT, multiple regression analysis was performed on 8324 samples, using clinical laboratory data of all test items requested simultaneously with APTT. To confirm the items extracted from the multiple regression analysis, the target substance was spiked to pooled plasma and measured with two APTT reagents. Additionally, by spiking phospholipids, the effect on APTT measurement system was assessed. RESULT: Multiple regression analysis detected albumin-globulin ratio (AGR), C-reactive protein (CRP), hematocrit, and prothrombin time as factors related to ΔAPTT (p < 0.001). Results revealed no significant differences when albumin was added to change the AGR. Whereas with the addition of CRP, prolongation of APTT was observed in Coagpia APTT-n compared to Thrombocheck APTT-SLA (p < 0.001). This prolongation was canceled by the addition of phospholipids, suggesting the interaction of CRP with phospholipids leads to the pseudo-prolongation. CONCLUSION: It is considered that the pseudo-prolongation of APTT is triggered by the interaction of CRP on the phospholipid in Coagpia APTT-n, which contributed to the APTT dissociation.

Glutamatergic neurons from the medial prefrontal cortex to the dorsal raphe nucleus regulate maternal aggression in lactating mice.

Glutamatergic signals in the dorsal raphe nucleus (DRN) regulate maternal aggression and care in mice. We examined whether glutamatergic input from the medial prefrontal cortex (mPFC) to the DRN might regulate maternal aggression and care in mice. In the maternal aggression test, each dam was exposed to an identical intruder male twice for 5 min, 60 min apart. During the latter trial (opt trial), the terminals of glutamatergic neurons from the mPFC to the DRN were manipulated using optogenetic techniques. Compared to the former trial (pre-opt trial), the inhibition of glutamatergic input in the opt trial decreased bite frequency and prevented the shortening of biting latency. In contrast, the activation of glutamatergic input at 5 Hz increased the biting frequency. Meanwhile, the activation of glutamatergic input at 1, 10, and 20 Hz prevented the shortening of biting latency without affecting biting frequency. In the maternal care test, activation of glutamatergic input at 5 Hz did not affect maternal care. Our results suggest that glutamatergic neurons from the mPFC to the DRN differently regulate maternal aggression, depending on temporal patterns of their activation, and that the glutamatergic signals that enhance maternal aggression are not involved in the regulation of maternal care.

Regulation of maternal care by corticotropin-releasing factor receptors in the dorsal raphe nucleus in mice.

We previously reported that the dorsal raphe nucleus (DRN) was involved in the regulation of maternal care in lactating female mice. The DRN receives multiple innervations from a variety of the brain regions. Corticotropin-releasing factor (CRF) Type 1 and Type 2 receptors are distributed in the DRN. Both receptors have been implicated in regulating negative aspects including stress, fear, and anxiety. However, it remains unknown how CRF receptors in the DRN regulate maternal care. In the present study, we investigated how CRF receptors in the DRN is involved in regulating maternal care in lactating female mice. Injection of antalarmin or antisauvagine-30, which is an antagonist of CRF Type 1 or Type 2 receptor, respectively, into the DRN increased the latency to retrieving pups into the nest and to crouching over pups, and decreased the duration of crouching over pups, indicating that blockage of CRF receptor signaling in the DRN decreased maternal care. Each treatment did not affect anxiety-related behaviors, which were assayed using the hole-board test. These results suggest that CRF receptor signaling in the DRN positively regulates maternal care in lactating female mice. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Combination of a SARS-CoV-2 IgG Assay and RT-PCR for Improved COVID-19 Diagnosis.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is generally diagnosed by reverse transcription (RT)-PCR or serological assays. The SARS-CoV-2 viral load decreases a few days after symptom onset. Thus, the RT-PCR sensitivity peaks at three days after symptom onset (approximately 80%). We evaluated the performance of the ARCHITECT® SARS-CoV-2 IgG assay (henceforth termed IgG assay; Abbott Laboratories, Lake County, IL, USA), and the combination of RT-PCR and the IgG assay for COVID-19 diagnosis. METHODS: In this retrospective study, 206 samples from 70 COVID-19 cases at two hospitals in Tokyo that were positive using RT-PCR were used to analyze the diagnostic sensitivity. RT-PCR-negative (N=166), COVID-19-unrelated (N=418), and Japanese Red Cross Society (N=100) samples were used to evaluate specificity. RESULTS: Sensitivity increased daily after symptom onset and exceeded 84.4% after 10 days. Specificity ranged from 98.2% to 100% for samples from the three case groups. Seroconversion was confirmed from 9 to 20 days after symptom onset in 18 out of 32 COVID-19 cases with multiple samples and from another case with a positive result in the IgG assay for the first available sample. CONCLUSIONS: The combination of RT-PCR and IgG assay improves the robustness of laboratory diagnostics by compensating for the limitations of each method.

Immunochromatography and chemiluminescent enzyme immunoassay for COVID-19 diagnosis.

INTRODUCTION: The rapid and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required to prevent the spread of COVID-19. This study evaluated the utility of two SARS-CoV-2 antigen detection methods. METHODS: We evaluated two types of antigen detection methods using immunochromatography (Espline) and quantitative chemiluminescent enzyme immunoassay (Lumipulse). RT-PCR was performed as a standard procedure for COVID-19 diagnosis. Lumipulse and RT-PCR were performed for all 486 nasopharyngeal swabs and 136 saliva samples, and the Espline test was performed for 271 nasopharyngeal swabs and 93 saliva samples. RESULTS: The sensitivity and specificity of the Espline test were 10/11 and 260/260 (100%), respectively for the nasopharyngeal swabs and 3/9 and 84/84 (100%), respectively for the saliva samples. High sensitivities for both saliva (8/9) and nasopharyngeal swabs (22/24) were observed in the Lumipulse test. The specificities of the Lumipulse test for nasopharyngeal swabs and saliva samples were 460/462 (99.6%) and 123/127 (96.9%), respectively. CONCLUSION: The Espline test is not effective for saliva samples but is useful for simple and rapid COVID-19 tests using nasopharyngeal swabs because it does not require special devices. The Lumipulse test is a powerful high-throughput tool for COVID-19 diagnosis because it has high detection performance for nasopharyngeal swabs and saliva samples.

Oral Administration of Probiotic Bifidobacterium breve Improves Facilitation of Hippocampal Memory Extinction via Restoration of Aberrant Higher Induction of Neuropsin in an MPTP-Induced Mouse Model of Parkinson's Disease.

We previously reported that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease (PD) model mice (PD mice) facilitate hippocampal memory extinction, which may be the cause of cognitive impairment in PD. Recent studies on the consumption of probiotics have reported a variety of beneficial effects on the central nervous system via the microbiota-gut-brain axis. In this study, we investigated the effects of oral administration of Bifidobacterium breve strain A1 [MCC1274] (B. breve A1) on the facilitation of hippocampal memory extinction observed in PD mice. We found that four-day consecutive oral administration of B. breve A1 restored facilitation of contextual fear extinction in PD mice. Hippocampal mRNA expression levels of postsynaptic density protein-95 and synaptophysin significantly decreased in the PD mice, but mRNA and protein expression levels of neuropsin increased. Furthermore, CA1 apical spine density was significantly reduced in PD mice. On the other hand, administration of B. breve A1 to PD mice recovered all these expression levels and the CA1 spine density to control levels. These results suggest that increased induction of neuropsin is involved in abnormal changes in hippocampal synaptic plasticity, and that B. breve A1 imposes reins on its expression, resulting in the restoration of abnormal hippocampal synaptic plasticity and the facilitation of fear extinction in PD mice.

Complete whole-genome sequence of the novel Pseudomonas species strain TUM18999, isolated from a patient with a burn wound in Japan.

OBJECTIVES: Pseudomonas is a Gram-negative bacterial genus with numerous member species. In this study, using whole-genome sequencing, we characterized a novel Pseudomonas sp. strain TUM18999, isolated as a pathogen from a human patient. METHODS: The TUM18999 strain was isolated from a patient's burn wound. Minimum inhibitory concentrations (MICs) were determined using the broth microdilution method. The whole-genome sequence was obtained using Miseq and MinION, and we conducted phylogenetic analysis based on single nucleotide polymorphisms of the core genome. RESULTS: Antimicrobial susceptibility testing revealed a high ceftazidime MIC (32 mg/L). Moreover, carbapenemase production was confirmed using the modified carbapenem inactivation method. We found that the complete genome of TUM18999 was 6,826,062 bp long, with 6175 coding sequences (CDS) and a DNA G+C content (non-plasmid) of 66.4 mol%. Consistent with the high similarities with the 16S rRNA sequences of P. otitidis MCC10330 (98.6%) and P. alcaligenes NBRC 14159 (99.2%), similarities (<90%) were also observed with the gyrB genes of both strains. The average nucleotide identities for P. alcaligenes NBRC 14159 and P. otitidis MCC10330 were also <90%. The core-genome single nucleotide polymorphism phylogenetic tree indicated that the TUM18999 strain was most closely related to P. otitidis MCC10330. In addition, the TUM18999 strain carried the novel gene, species-specific subclass B3 metallo-ß-lactamase (MBL), and its similarities with P. alcaligenes metallo-ß-lactamase-1 (PAM-1) and P. otitidis metallo-ß-lactamase-1 (POM-1) were 90.24% and 73.14%, respectively. CONCLUSION: We characterized the complete whole genome sequence of the novel Pseudomonas sp. TUM18999 carrying the novel gene species-specific subclass B3 MBL.

Investigation of the factors that induce maternal aggression towards juveniles among several mouse strains.

Maternal care and aggression are representative of maternal behavior among lactating female mice. Even neonates and juveniles, who are not biological offspring, can induce maternal care and aggression in dams. Here, we investigated the factors that induce maternal aggression through exposure to juvenile mice. We first addressed the role of intruder age on the induction of maternal aggression in dams. BALB/c dams displayed attacking behavior towards 14-day-old C57BL/6J male intruders. Consumption of food pellets during the weaning period was unlikely to affect the induction of attacking behavior, as the intruders reared by breastfeeding, without food pellets, induced intensive attacking behavior in dams. Next, we compared the intruder-mediated induction of attacking behavior through different mouse strains. Specifically, BALB/c intruders induced a lower level of attacking behavior in BALB/c or ICR dams, compared to the other strains tested. However, BALB/c intruders induced intense attacking behavior in C57BL/6N dams, indicating that the occurrence of attacking behavior is dependent on the strains of dams as well as intruders. A cross-fostering experiment highlighted that the rearing by an original mother was required for C57BL/6J juveniles to induce attacking behavior. In contrast, BALB/c intruders may emit an inhibitory factor that limits attacking behavior. We finally explored which parts of the body emit these aggression-inducible signals. Removal of body hair around the proximal tail of the intruders significantly decreased the attacking behavior of dams, demonstrating that chemical cues, namely pheromones, attached to the body hair around the proximal tail may be essential for inducing attacking behavior in dams.

Oxytocin in the dorsal raphe nucleus antagonizes the inhibition of maternal care induced by food deprivation.

Lactation is indispensable for the pup's survival, but is considered a survival burden in dams under negative energy conditions. In the present study, we tested our hypothesis that oxytocin may facilitate energy investment to pups through behavioral control as well as milk ejection. Maternal care was observed in dams at 3 h but not 8 h after food deprivation. We investigated whether oxytocin in the dorsal raphe nucleus (DRN), which is involved in energy state-dependent regulation of maternal care, regulates maternal care. For this purpose, 2-pmol L368899, an oxytocin receptor antagonist, was injected into the DRN; after treatment, maternal care was inhibited in the dams with 3-h fasting, but not in the fed dams. In contrast, recovery of maternal care was observed in the dams with 8-h fasting who underwent 100-pmol oxytocin injection at the DRN. These results indicate that oxytocin in the DRN is required for displaying maternal behavior under fasting conditions, but not under fed conditions. Next, we investigated the site of oxytocin release. Presentation of pups decreased the oxytocin immunoreactivity at the paraventricular nucleus (PVN) of the hypothalamus in the 3-h-fasted dams, but not in the fed or 8-h-fasted dams. No change of the serum oxytocin level was observed. Few oxytocin-positive neurons projecting from the PVN to the DRN were detected through labeling with the retrograde tracer fluorogold. Oxytocin secreted at the PVN, which reaches the DRN, but not released as a hormone or neurotransmitter may mediate maternal care under food-restricted conditions.

Measuring individual external doses of Tokyo Electric Power Company Holdings employees living in Fukushima prefecture.

Since the accident at Fukushima Daiichi Nuclear Power Plant, individual external doses of residents have been investigated. To accurately analyse survey data, a variety of information, including the activity patterns of many residents, needs to be integrated. However, such large-scale surveys have not yet been conducted and actual individual external doses in Fukushima are unclear. In this study, the individual external doses of approximately 300 Tokyo Electric Power Company Holdings employees, who live and work in Fukushima Prefecture outside the Fukushima Daiichi Nuclear Power Plant, were measured. The employees carried GPS loggers and personal dosimeters capable of measuring dose in counts per minute. The employees' individual external doses were compared along with their activity patterns. It was found that the annual additional individual external dose estimated based upon actual measurements was 1 mSv or less, and the influence on the individual external dose was also revealed.

Serotonin 5-HT4 Receptor Agonists Improve Facilitation of Contextual Fear Extinction in an MPTP-Induced Mouse Model of Parkinson's Disease.

Previously, we found that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) model mice (PD mice) showed facilitation of hippocampal memory extinction via reduced cyclic adenosine monophosphate (cAMP)/cAMP-dependent response element-binding protein (CREB) signaling, which may cause cognitive impairment in PD. Serotonergic neurons in the median raphe nucleus (MnRN) project to the hippocampus, and functional abnormalities have been reported. In the present study, we investigated the effects of the serotonin 5-HT4 receptor (5-HT4R) agonists prucalopride and velusetrag on the facilitation of memory extinction observed in PD mice. Both 5-HT4R agonists restored facilitation of contextual fear extinction in PD mice by stimulating the cAMP/CREB pathway in the dentate gyrus of the hippocampus. A retrograde fluorogold-tracer study showed that γ-aminobutyric acid-ergic (GABAergic) neurons in the reticular part of the substantia nigra (SNr), but not dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNpc), projected to serotonergic neurons in the MnRN, which are known to project their nerve terminals to the hippocampus. It is possible that the degeneration of the SNpc DAergic neurons in PD mice affects the SNr GABAergic neurons, and thereafter, the serotonergic neurons in the MnRN, resulting in hippocampal dysfunction. These findings suggest that 5HT4R agonists could be potentially useful as therapeutic drugs for treating cognitive deficits in PD.

Performance evaluation of an Indoxyl Sulfate Assay Kit "NIPRO".

Background The relationship between renal disease and cardiovascular disease (CVD) is currently known as cardiorenal syndrome. Indoxyl sulfate (IS) is one of the uremic toxins that accelerates the progression of cardiorenal syndrome. This report presents a new method for measuring IS in a simpler way. Methods We evaluated the analytical performance of an IS Assay Kit "NIPRO" loaded on LABOSPECT 008. The evaluated analytical performances included accuracy, precision, dilution linearity, limit of detection (LOD), limit of quantitation (LOQ), recovery test, interference test and comparison against assays performed by high-performance liquid chromatography (HPLC). Results Total precision showed a <5.3% coefficient of variation at IS concentrations of 3.57-277.73 µmol/L, and satisfactory results were observed in the dilution linearity, LOD, LOQ, recovery and interference tests. The IS Assay Kit "NIPRO" showed a high correlation with the HPLC conventional method (r = 0.993). Conclusions The IS Assay Kit "NIPRO" demonstrated satisfactory analytical performance, and this suggests it could shortly become another common method to measure circulating IS.

Glutamatergic Signals in the Dorsal Raphe Nucleus Regulate Maternal Aggression and Care in an Opposing Manner in Mice.

Lactating female mice nurture their pups and attack intruders in their territory. When an intruder invades a dam's territory, she needs to switch her behavior from care to aggression to protect her pups and territory. Although the neuronal mechanisms underlying each distinct behavior have been studied, it is unclear how these behaviors are displayed alternatively. The dorsal raphe nucleus (DRN) regulates both nurturing and aggressive behaviors. In the present study, we examined whether the DRN is involved in regulating alternative display of maternal care and aggression. We first examined neuronal activity in the medial prefrontal cortex (mPFC) and lateral habenula (LHb), which send glutamatergic input to the DRN, in dams by injecting Fluorogold, a retrograde tracer, into the DRN. The number of c-Fos- and Fluorogold-positive neurons in the mPFC and LHb increased in the dams that displayed biting behavior in response to an intruder, but remained unchanged in the dams that displayed nurturing behavior. Injections of N-methyl-d-aspartic acid (NMDA) receptor antagonists or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor antagonists into the DRN inhibited biting behavior but not nurturing behavior. In contrast, injections of NMDA or AMPA into the DRN inhibited nurturing behavior. These results suggest that glutamatergic signals in the DRN, which may originate from the mPFC and/or LHb, regulate the preferential display of biting behavior over nurturing behavior in dams.

Feasibility study of large-scale production of iodine-125 at the high temperature engineering test reactor.

The feasibility of a large-scale iodine-125 production from natural xenon gas at high-temperature gas-cooled reactors (HTGRs) was investigated. A high-temperature engineering test reactor (HTTR), which is located in Japan at Oarai-machi Research and Development Center, was used as a reference HTGR reactor in this study. First, a computer code based on a Runge-Kutta method was developed to calculate the quantities of isotopes arising from the neutron irradiation of natural xenon gas target. This code was verified with a good agreement with a reference result. Next, optimization of irradiation planning was carried out. As results, with 4 days of irradiation and 8 days of decay, the 125I production could be maximized and the 126I contamination was within an acceptable level. The preliminary design of irradiation channels at the HTTR was also optimized. The case with 3 irradiation channels and 20-cm diameter was determined as the optimal design, which could produce approximately 1.8 × 105GBq/y of 125I production.

Muscarinic M2 receptor promotes vasopressin synthesis in mice supraoptic nuclei.

Muscarinic acetylcholine receptors have been suggested to be implicated in arginine-vasopressin secretion because intracerebroventricular muscarinic agonist administration induces arginine-vasopressin release into the circulation. Although which subtype is involved in the regulation of arginine-vasopressin secretion is unclear, M2 receptors have been reported to be highly expressed in the hypothalamus. In the present study, M2 receptor-knockout mice were used to elucidate whether M2 receptor regulates arginine-vasopressin synthesis in the paraventricular nuclei and supraoptic nuclei of the hypothalamus. The number of arginine-vasopressin-immunoreactive neurons in M2 receptor-knockout mice was significantly decreased in the supraoptic nuclei, but not in the paraventricular nuclei compared with wild-type mice. Plasma arginine-vasopressin level in M2 receptor-knockout mice was also significantly lower than in the wild-type mice. Urinary volume and frequency as well as water intake in M2 receptor-knockout mice were significantly higher than those in wild-type mice. The V2 vasopressin receptor expression in kidneys of M2 receptor-knockout mice was comparable with that of wild-type mice, and increased urination in M2 receptor-knockout mice was significantly decreased by administration of desmopressin, a specific V2 receptor agonist, suggesting that V2 receptors in the kidneys of M2 receptor-knockout mice are intact. These results suggest that M2 receptors promote arginine-vasopressin synthesis in the supraoptic nuclei and play a role in the regulation and maintenance of body fluid.

Proposal of a neutron transmutation doping facility for n-type spherical silicon solar cell at high-temperature engineering test reactor.

The p-type spherical silicon solar cell is a candidate for future solar energy with low fabrication cost, however, its conversion efficiency is only about 10%. The conversion efficiency of a silicon solar cell can be increased by using n-type silicon semiconductor as a substrate. This study proposed a new method of neutron transmutation doping silicon (NTD-Si) for producing the n-type spherical solar cell, in which the Si-particles are irradiated directly instead of the cylinder Si-ingot as in the conventional NTD-Si. By using a 'screw', an identical resistivity could be achieved for the Si-particles without a complicated procedure as in the NTD with Si-ingot. Also, the reactivity and neutron flux swing could be kept to a minimum because of the continuous irradiation of the Si-particles. A high temperature engineering test reactor (HTTR), which is located in Japan, was used as a reference reactor in this study. Neutronic calculations showed that the HTTR has a capability to produce about 40t/EFPY of 10Ωcm resistivity Si-particles for fabrication of the n-type spherical solar cell.

The Accessory Olfactory System Facilitates the Recovery of the Attraction to Familiar Volatile Female Odors in Male Mice.

Odors in female mice induce sexual arousal in male mice. Repeated exposure to female odors attenuates male attraction, which recovers when the odors are removed. The neuronal mechanisms for the recovery of male attraction have not been clarified. In this study, we examined how olfactory systems are involved in the recovery of male attraction to female odors following habituation in mice. Presentation with volatile female odors for 5 min induced habituation in males. To evaluate male attraction to familiar volatile female odors, we measured the duration for investigating volatile female odors from the same female mouse, which was presented twice for 5 min with 1-, 3-, or 5-min interval. Intranasal irrigation with ZnSO4 solution almost completely suppressed investigating behavior, indicating that the main olfactory system is indispensable for inducing the attraction to volatile female odors. In contrast, removal of the vomeronasal organ, bilateral lesions of the accessory olfactory bulb (AOB), or pharmacological blockage of neurotransmission in the AOB did not affect the investigation time at the first odor presentation. However, each one of the treatments decreased the investigation time in the second presentation, compared to that in the first presentation, at longer intervals than control treatment, indicating that the disturbance of neurotransmission in the accessory olfactory system delayed the recovery of the attraction attenuated by the first presentation. These results suggest that the accessory olfactory system facilitates the recovery of the attraction to familiar volatile female odors in male mice.