Targeting cathepsin S promotes activation of OLF1-BDNF/TrkB axis to enhance cognitive function.

BACKGROUND: Cathepsin S (CTSS) is a cysteine protease that played diverse roles in immunity, tumor metastasis, aging and other pathological alterations. At the cellular level, increased CTSS levels have been associated with the secretion of pro-inflammatory cytokines and disrupted the homeostasis of Ca2+ flux. Once CTSS was suppressed, elevated levels of anti-inflammatory cytokines and changes of Ca2+ influx were observed. These findings have inspired us to explore the potential role of CTSS on cognitive functions. METHODS: We conducted classic Y-maze and Barnes Maze tests to assess the spatial and working memory of Ctss-/- mice, Ctss+/+ mice and Ctss+/+ mice injected with the CTSS inhibitor (RJW-58). Ex vivo analyses including long-term potentiation (LTP), Golgi staining, immunofluorescence staining of sectioned whole brain tissues obtained from experimental animals were conducted. Furthermore, molecular studies were carried out using cultured HT-22 cell line and primary cortical neurons that treated with RJW-58 to comprehensively assess the gene and protein expressions. RESULTS: Our findings reported that targeting cathepsin S (CTSS) yields improvements in cognitive function, enhancing both working and spatial memory in behavior models. Ex vivo studies showed elevated levels of long-term potentiation levels and increased synaptic complexity. Microarray analysis demonstrated that brain-derived neurotrophic factor (BDNF) was upregulated when CTSS was knocked down by using siRNA. Moreover, the pharmacological blockade of the CTSS enzymatic activity promoted BDNF expression in a dose- and time-dependent manner. Notably, the inhibition of CTSS was associated with increased neurogenesis in the murine dentate gyrus. These results suggested a promising role of CTSS modulation in cognitive enhancement and neurogenesis. CONCLUSION: Our findings suggest a critical role of CTSS in the regulation of cognitive function by modulating the Ca2+ influx, leading to enhanced activation of the BDNF/TrkB axis. Our study may provide a novel strategy for improving cognitive function by targeting CTSS.

Therapeutic efficacy of probiotics for symptoms of attention-deficit hyperactivity disorder in children and adolescents: meta-analysis.

BACKGROUND: The efficacy of probiotics as a therapeutic alternative for attention-deficit hyperactivity disorder (ADHD) remain unclear. AIMS: To investigate the effectiveness of probiotics for symptoms of ADHD and identify possible factors affecting their efficacy. METHOD: Randomised placebo-controlled trials were identified through searching major databases from inception to April 2023, using the main keywords 'probiotics' and 'ADHD' without limitation on languages or geographic locations. The outcome of interest included improvement in total symptoms of ADHD, symptoms of inattention and hyperactivity/impulsivity, and drop-out rate. Continuous and categorical data were expressed as effect sizes based on standardised mean differences (SMDs) and odds ratios, respectively, with 95% confidence intervals. RESULTS: Meta-analysis of seven trials involving 379 participants (mean age 10.37 years, range 4-18 years) showed no significant improvement in total symptoms of ADHD (SMD = 0.25; P = 0.12), symptoms of inattention (SMD = 0.14; P = 0.3) or hyperactivity/impulsivity (SMD = 0.08; P = 0.54) between the probiotic and placebo groups. Despite non-significance on subgroup analyses, there was a large difference in effect size between studies using probiotics as an adjunct to methylphenidate and those using probiotics as supplementation (SMD = 0.84 v. 0.07; P = 0.16), and a moderate difference in effect size between studies using multiple strains of probiotics and those using single-strain regimens (SMD = 0.45 v. 0.03; P = 0.19). CONCLUSIONS: Current evidence shows no significant difference in therapeutic efficacy between probiotics and placebos for treatment of ADHD symptoms. However, albeit statistically non-significant, higher therapeutic efficacies associated with multiple-strain probiotics or combining probiotics with methylphenidate may provide direction for further research.

Pretreatment with Lovastatin Improves Depression-Like Behavior After Traumatic Brain Injury Through Activation of the AMPK Pathway.

BACKGROUND: The beneficial effect of pretreatment with statins on traumatic brain injury (TBI)-induced depression and anxiety and its mechanism of action remain unclear. In this study, we combined epidemiological and experimental animal data to clarify this issue. METHODS: We used the Taiwan National Health Insurance database to identify patients who were diagnosed with TBI from 2000 to 2013 and compared patients with and without statin treatment matched by age, sex, and underlying comorbidities in a 1:1 ratio. The risk of developing depression and/or anxiety was compared between patients with and without a statin using Cox proportional hazards regression. We also used a rat model to assess the effect of lovastatin pretreatment on neurobehavioral and neuropathological changes following TBI. RESULTS: The risk of developing depression was lower in the 41,803 patients in the statin cohort than nonstatin cohort (adjusted hazard ratio, 0.91 [95% confidence interval, 0.83-0.99]). In animal models, the lovastatin group had significantly reduced infarct volume, decreased immobility time and latency to eat, a reduced number of Fluoro- Jade-positive cells and levels of glial fibrillary acidic protein and tumor necrosis factor-alpha, and increased adenosine monophosphate -activated protein kinase (AMPK) and its upstream kinase liver kinase B1 in the hippocampal dentate gyrus. These effects were blocked in AMPK inhibitor-pretreated TBI rats. CONCLUSIONS: Our epidemiological data showed that a decreased risk of depression was associated with statin pretreatment, which was supported by an animal study. The underlying mechanism for this appears to involve AMPK activation in the statin pretreatment-induced alleviation of TBI.

Dissolution behavior of ZnO nanoparticles at environmentally relevant low concentrations in surface waters: Equilibrium and kinetics.

Environmentally relevant fate parameters are essential in accurate prediction of nanomaterial's exposure. This study investigates the dissolution kinetics and equilibrium of ZnO nanoparticles (ZnONPs) using environmentally relevant low concentrations (50-200 µg/L) of ZnONPs in river water and lake water samples, and a seawater-influenced river water. We found that ZnONPs at an initial concentration of 50 µg/L completely dissolved independent of water matrices, while at 100 and 200 µg/L the dissolution level of ZnONPs was strongly dependent on the water chemistry. Carbonate alkalinity was found to control the dissolution levels, and can react with dissolved Zn ion to form secondary solid product hydrozincite. An analysis of our kinetic data and comprehensive literature results reveals that the dissolution kinetic coefficients largely increased with decreased initial ZnONP concentrations especially in environmental water matrices. The result highlights the importance to measure and derive representative dissolution parameters of nanomaterials using environmentally relevant concentrations.

Modulation of methamphetamine memory reconsolidation by neural projection from basolateral amygdala to nucleus accumbens.

Drug-associated conditioned cues promote subjects to recall drug reward memory, resulting in drug-seeking and reinstatement. A consolidated memory becomes unstable after recall, such that the amnestic agent can disrupt the memory during the reconsolidation stage, which implicates a potential therapeutic strategy for weakening maladaptive memories. The basolateral amygdala (BLA) involves the association of conditioned cues with reward and aversive valences and projects the information to the nucleus accumbens (NAc) that mediates reward-seeking. However, whether the BLA-NAc projection plays a role in drug-associated memory reactivation and reconsolidation is unknown. We used methamphetamine (MeAM) conditioned place preference (CPP) to investigate the role of BLA-NAc neural projection in the memory reconsolidation. Two weeks before CPP training, we infused adeno-associated virus (AAV) carrying the designer receptor exclusively activated by designer drugs (DREADD) or control constructs. We infused clozapine-N-oxide (CNO) after the recall test to manipulate the neural activity of BLA-NAc projections in mice. We found that after recall, DREADD-mediated inhibition of BLA neurons projecting to the NAc core blunted consolidated MeAM-associated memory. Inhibition of BLA glutamatergic nerve terminals in the NAc core 1 h after recall disrupted consolidated MeAM-associated memory. However, inhibiting this pathway after the time window of reconsolidation failed to affect memory. Furthermore, under the condition without memory retrieval, DREADD-mediated activation of BLA-NAc core projection was required for amnesic agents to disrupt consolidated MeAM-associated memory. Our findings provide evidence that the BLA-NAc pathway activity is involved in the post-retrieval processing of MeAM-associated memory in CPP.

Regulation of stress-provoked aggressive behavior using endocannabinoids.

Reactive impulsive aggression is characterized by outbursts of rage and violence when subjects encounter threatening stressful events. Although impulsive aggression and violence create a high-cost burden on health and society, relatively little is known about treatment. Early adolescent social isolation (SI) alters brain development and functions. It induces hyper-excitatory in the ventral hippocampus (vHip) to promote acute stress-provoked outbursts of aggression, referred to as impulsive aggression, in mouse models. Cannabinoid type 1 receptors (CB1Rs) act on presynaptic sites and suppress neurotransmitter release into synapses. Given that CB1R activation inhibits neurotransmitter releases and modulates excitatory network activity, we tested the hypothesis that CB1R activation reduces impulsive aggression in SI mice through decreasing excitatory activity in the vHip. Here, we report that CB1R agonists, WIN-552122 (WIN) or arachidonylcyclopropylamide (ACPA), ameliorated acute stress-provoked attack behavior in the resident-intruder test without affecting general locomotion activity. Increasing endocannabinoids (eCBs) by inhibiting degradation enzymes in the vHip reduced impulsive aggression, and the effect was blunted by administration of AM251, a CB1R antagonist. Acute stress in SI mice induced c-Fos expression, a marker of neuronal activation, on vHip neurons projecting to the ventromedial hypothalamus (VMH), a well-known brain area that controls attack behavior. eCB augmentation inhibited c-Fos expression in VMH-projecting vHip neurons surrounded by CB1Rs. These results suggest that enhancing eCB signaling in order to activate CB1Rs suppresses impulsive aggression via suppressing vHip→VMH neural activity and point to a role of CB1R activation in ameliorating impulsive aggression in adults who have had adverse experiences during early adolescence.

A Review on the Environmental Fate Models for Predicting the Distribution of Engineered Nanomaterials in Surface Waters.

Exposure assessment is a key component in the risk assessment of engineered nanomaterials (ENMs). While direct and quantitative measurements of ENMs in complex environmental matrices remain challenging, environmental fate models (EFMs) can be used alternatively for estimating ENMs' distributions in the environment. This review describes and assesses the development and capability of EFMs, focusing on surface waters. Our review finds that current engineered nanomaterial (ENM) exposure models can be largely classified into three types: material flow analysis models (MFAMs), multimedia compartmental models (MCMs), and spatial river/watershed models (SRWMs). MFAMs, which is already used to derive predicted environmental concentrations (PECs), can be used to estimate the releases of ENMs as inputs to EFMs. Both MCMs and SRWMs belong to EFMs. MCMs are spatially and/or temporally averaged models, which describe ENM fate processes as intermedia transfer of well-mixed environmental compartments. SRWMs are spatiotemporally resolved models, which consider the variability in watershed and/or stream hydrology, morphology, and sediment transport of river networks. As the foundation of EFMs, we also review the existing and emerging ENM fate processes and their inclusion in recent EFMs. We find that while ENM fate processes, such as heteroaggregation and dissolution, are commonly included in current EFMs, few models consider photoreaction and sulfidation, evaluation of the relative importance of fate processes, and the fate of weathered/transformed ENMs. We conclude the review by identifying the opportunities and challenges in using EFMs for ENMs.

MicroRNA-206 Regulates Stress-Provoked Aggressive Behaviors in Post-weaning Social Isolation Mice.

When facing stressful conditions, some people tend to be impulsively aggressive whereas others are not. However, the causes and underlying mechanisms remain elusive. It has been reported that acute stress induces outbursts of aggression in post-weaning social isolation (SI) mice but not in group housing (GH) mice. Here we report epigenetic regulation of impulsive aggression in SI mice. At post-natal day 21, mice were randomly assigned to GH or SI groups. We found that SI mice exhibited a higher level of microRNA 206 (miR-206) compared with GH mice. Intra-hippocampal injection of AM206, an antagomir of miR-206, decreased stress-induced attack behavior in SI mice and increased BDNF expression. Moreover, BDNF expression was required for AM206 effects on the reduction of aggression. On the other hand, miR-206 overexpression in GH mice induced attack behavior. Intranasal administration of AM206 rather than a scramble control significantly reduced attack behavior and depression-like behavior in SI mice. Our results suggest that miR-206 mediates development of maladaptive impulsive aggression in early life adversity and that its antagomir could potentially be a therapeutic target against stress-exacerbated aggressive behavior.

The Ventral Hippocampus Controls Stress-Provoked Impulsive Aggression through the Ventromedial Hypothalamus in Post-Weaning Social Isolation Mice.

Impulsively aggressive individuals may suddenly attack others when under stress, but the neural circuitry underlying stress-provoked aggression is poorly understood. Here, we report that acute stress activates ventral hippocampus (vHip) neurons to induce attack behavior in post-weaning socially isolated mice. Chemogenetic inhibition of vHip neural activity blunts stress-provoked attack behavior, whereas chemogenetic activation promotes it. The activation of cell bodies in vHip neurons projecting into the ventromedial hypothalamus (VMH) induces attack behavior, suggesting that the vHip-VMH projection contributes to impulsive aggression. Furthermore, optogenetic inhibition of vHip glutamatergic neurons blocks stress-provoked attacks, whereas optogenetic activation of vHip glutamatergic neurons drives attack behavior. These results show direct evidence that vHip-VMH neural circuitry modulates attack behavior in socially isolated mice.

Effects of Epiphytes and Depth on Seagrass Spectral Profiles: Case Study of Gulf St. Vincent, South Australia.

Seagrasses are a crucial indicator species of coastal marine ecosystems that provide substratum, shelter, and food for epiphytic algae, invertebrates, and fishes. More accurate mapping of seagrasses is essential for their survival as a long-lasting natural resource. Before reflectance spectra could properly be used as remote sensing endmembers, factors that may obscure the detection of reflectance signals must be assessed. The objectives in this study are to determine the influence of (1) epiphytes, (2) water depth, and (3) seagrass genus on the detection of reflectance spectral signals. The results show that epiphytes significantly dampen bottom-type reflectance throughout most of the visible light spectrum, excluding 670-679 nm; the depth does influence reflectance, with the detection of deeper seagrasses being easier, and as the depth increases, only Heterozostera increase in the exact "red edge" wavelength at which there is a rapid change in the near-infrared (NIR) spectrum. These findings helped improve the detection of seagrass endmembers during remote sensing, thereby helping protect the natural resource of seagrasses.

Mechanism underlying NMDA blockade-induced inhibition of aggression in post-weaning socially isolated mice.

When faced with stressful conditions, people with a tendency toward impulsive aggression may suddenly hurt others. We have previously shown that the blockade of NMDA receptors (NMDARs) within the ventral hippocampus (VH) produces anti-aggressive effects. However, little is known about the mechanism for tamping down stress-provoked attack behavior. Here, we report that expression of brain-derived neurotrophic factor (BDNF) after inhibition of NMDARs in the VH is required for blunting stress-provoked attack behavior in post-weaning socially isolated mice. Administration of NMDAR antagonist MK-801 decreased the phosphorylated eukaryotic elongation factor 2 (p-eEF2) and increased BDNF expression in the VH. Infusion of eEF2 kinase inhibitor NH125 to the VH decreased attack behavior and increased BDNF expression. Knockdown of BDNF in the VH blocked the anti-aggressive effect of MK-801 and NH125. Furthermore, MK-801 rapidly increased the activity of protein phosphatase 2A (PP2A). Intra-VH infusion of PP2A inhibitor okadaic acid blocked the anti-aggressive effects of MK-801. These results suggest that blockade of NMDAR reduces attack behavior through increasing PP2A activity leading to dephosphorylation of eEF2 and an increase in BDNF expression. Our findings indicate that the enhancement of BDNF expression is beneficial for preventing impulsive aggression in at-risk beings.

Impact of social relationships on Alzheimer's memory impairment: mechanistic studies.

Alzheimer's disease (AD) is characterized by progressive memory and neuronal loss culminating in cognitive impairment that not only affects a person's living ability but also becomes a society's as well as a family's economic burden. AD is the most common form of dementia in older persons. It is expected that the number of people with AD dementia will increase dramatically in the next 30 years, projecting to 75 million in 2030 and 131.5 million in 2050 worldwide. So far, no sufficient evidence is available to support that any medicine is able to prevent or reverse the progression of the disease. Early studies have shown that social environment, particularly social relationships, can affect one's behavior and mental health. A study analyzing the correlation between loneliness and risk of developing AD revealed that lonely persons had higher risk of AD compared with persons who were not lonely. On the other hand, it has been reported that we can prevent cognitive decline and delay the onset of AD if we keep mentally active and frequently participate in social activities. In this review, we focus on the impact of social behaviors on the progression of cognitive deficit in animal models of AD with a particular emphasis on a mechanistic scheme that explains how social isolation exacerbates cognitive impairment and how social interaction with conspecifics rescues AD patients' memory deficit.

Involvement of protein phosphatases in the destabilization of methamphetamine-associated contextual memory.

Destabilization refers to a memory that becomes unstable when reactivated and is susceptible to disruption by amnestic agents. Here we delineated the cellular mechanism underlying the destabilization of drug memory. Mice were conditioned with methamphetamine (MeAM) for 3 d, and drug memory was assessed with a conditioned place preference (CPP) protocol. Anisomycin (ANI) was administered 60 min after the CPP retrieval to disrupt reconsolidation. We found that destabilization of MeAM CPP after the application of ANI was blocked by the N-methyl-d-aspartate receptor (NMDAR) antagonist MK-801 and the NR2B antagonist ifenprodil (IFN) but not by the NR2A antagonist NVP-AAM077 (NVP). In addition, decrease in the phosphorylation of GluR1 at Serine845 (p-GluR1-Ser845), decrease in spine density, and a reduction in the AMPAR/NMDAR ratio in the basolateral amygdala (BLA) were reversed after the MK-801 treatment. The effect of ANI on destabilization was prevented by the protein phosphatase 2B (calcineurin, CaN) inhibitors cyclosporine A (CsA) and FK-506 and the protein phosphatase 1 (PP1) inhibitors calyculin A (CA) and okadaic acid (OA). These results suggest that memory destabilization involves the activation of NR2B-containing NMDARs, which in turn allows the influx of Ca(2+) Increased intracellular Ca(2+) stimulates CaN, leading to the dephosphorylation and inactivation of inhibitor 1 and the activation of PP1. PP1 then dephosphorylates p-GluR1-Ser845 to elicit AMPA receptor (AMPAR) endocytosis and destabilization of the drug memory.

Significant treatment effect of adjunct music therapy to standard treatment on the positive, negative, and mood symptoms of schizophrenic patients: a meta-analysis.

BACKGROUND: Music therapy (MT) has been used as adjunct therapy for schizophrenia for decades. However, its role is still inconclusive. A recent meta-analysis demonstrated that MT for schizophrenic patients only significantly benefits negative symptoms and mood symptoms rather than positive symptoms. In addition, the association between specific characteristics of MT and the treatment effect remains unclear. The aim of this study was to update the published data and to explore the role of music therapy in adjunct treatment in schizophrenia with a thorough meta-analysis. METHODS: We compared the treatment effect in schizophrenic patients with standard treatment who did and did not receive adjunct MT through a meta-analysis, and investigated the clinical characteristics of MT through meta-regression. RESULTS: The main finding was that the treatment effect was significantly better in the patients who received adjunct MT than in those who did not, in negative symptoms, mood symptoms, and also positive symptoms (all p < 0.05). This significance did not change after dividing the patients into subgroups of different total duration of MT, amounts of sessions, or frequency of MT. Besides, the treatment effect on the general symptoms was significantly positively associated with the whole duration of illness, indicating that MT would be beneficial for schizophrenic patients with a chronic course. CONCLUSIONS: Our meta-analysis highlights a significantly better treatment effect in schizophrenic patients who received MT than in those who did not, especially in those with a chronic course, regardless of the duration, frequency, or amounts of sessions of MT. These findings provide evidence that clinicians should apply MT for schizophrenic patients to alleviate disease severity.

Involvement of metabotropic glutamate receptor 5 in the inhibition of methamphetamine-associated contextual memory after prolonged extinction training.

Addiction is thought to be a memory process between perception and environmental cues and addicted patients often relapse when they come into contact with the drug-related context once again. Here, we used a conditioned place preference protocol to seek a more effective extinction methodology of methamphetamine (METH) memory and delineate its underlying mechanism. Conditioning METH for 3 days in mice markedly increased the time spent in the METH-paired compartment. Then the mice were conditioned with saline for 6 days, from day 6 to day 11, a procedure termed extinction training. However, METH memory returned after a priming injection of METH. We prolonged extinction duration from 6 to 10 days and found that this extensive extinction (EE) training prevented priming effect. At the molecular level, we discovered that prolonged extinction training reversed the METH-conditioned place preference-induced increase in surface expression of GluA2 and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/NMDA ratio in the basolateral amygdala. In addition, we found that extinction with metabotropic glutamate receptor 5 (mGluR5) activation had similar results to EE: reduced relapse after extinction, decreased synaptic AMPA receptors AMPARs and the AMPA/NMDA ratio. On the contrary, EE with mGluR5 inhibition suppressed the results of EE. These data indicate that EE training-elicited inhibition of METH-primed reinstatement is mediated by the mGluR5. Conditioning mice with methamphetamine place preference (METH CPP) increases surface expression of AMPA receptors (AMPARs) in the basolateral amygdala. We found prolongation of extinction duration from 6 to 10 days prevented priming effect. At the molecular level, we discovered that extensive extinction (EE) reversed the METH CPP-induced increase in surface expression of GluA2 and AMPA/NMDA ratio. In addition, we found that extinction with the metabotropic glutamate receptor 5 (mGluR5) activation had similar results to EE: reduced relapse after extinction, decreased synaptic AMPARs and the AMPA/NMDA ratio. On the contrary, EE with mGluR5 inhibition suppressed the results of EE. These data indicate that EE training-elicited inhibition of METH-primed reinstatement is mediated by mGluR5 (PAM: positive allosteric modulator).

Atypical neuroleptic malignant syndrome in patients treated with aripiprazole and clozapine: a case-series study and short review.

OBJECTIVES: Neuroleptic malignant syndrome (NMS) requires emergency treatment and can be fatal. Combined aripiprazole and clozapine therapy is rarely used in clinical settings, and NMS related this combination still lacks evaluation. Herein, we present two cases of atypical NMS treated with aripiprazole and clozapine. METHODS: Case 1 was a schizophrenic male with a history of NMS under treatment with aripiprazole 20 mg. He was hospitalized and maintained with aripiprazole 5 mg and clozapine 225 mg. On the 25th day, atypical NMS occurred with rigidity, elevated creatine kinase, and stupor, which subsided with supportive therapy. He was discharged under treatment with aripiprazole 15 mg and fluoxetine 60 mg. Case 2 was a female with schizoaffective disorder without a history of NMS. She was hospitalized and maintained with clozapine 50 mg and aripirazole 30 mg. On the 11th day, atypical NMS occurred with mild fever, delirium, and rigidity, which subsided under supportive therapy. RESULTS AND CONCLUSIONS: Our cases highlight the atypical features of NMS in patients being treated with combined ari-piprazole and clozapine. Consciousness change, modest elevation of creatine kinase, and leukocytosis were the most consistent findings; hyperthermia accounts for only some of the cases. This is a reminder of the importance of earlier detection of the soft signs and atypical features of NMS under this combined treatment.

Development of ocean color algorithms for estimating chlorophyll-a concentrations and inherent optical properties using gene expression programming (GEP).

This paper proposes new inversion algorithms for the estimation of Chlorophyll-a concentration (Chla) and the ocean's inherent optical properties (IOPs) from the measurement of remote sensing reflectance (Rrs). With in situ data from the NASA bio-optical marine algorithm data set (NOMAD), inversion algorithms were developed by the novel gene expression programming (GEP) approach, which creates, manipulates and selects the most appropriate tree-structured functions based on evolutionary computing. The limitations and validity of the proposed algorithms are evaluated by simulated Rrs spectra with respect to NOMAD, and a closure test for IOPs obtained at a single reference wavelength. The application of GEP-derived algorithms is validated against in situ, synthetic and satellite match-up data sets compiled by NASA and the International Ocean Color Coordinate Group (IOCCG). The new algorithms are able to provide Chla and IOPs retrievals to those derived by other state-of-the-art regression approaches and obtained with the semi- and quasi-analytical algorithms, respectively. In practice, there are no significant differences between GEP, support vector regression, and multilayer perceptron model in terms of the overall performance. The GEP-derived algorithms are successfully applied in processing the images taken by the Sea Wide Field-of-view Sensor (SeaWiFS), generate Chla and IOPs maps which show better details of developing algal blooms, and give more information on the distribution of water constituents between different water bodies.

Social isolation-induced increase in NMDA receptors in the hippocampus exacerbates emotional dysregulation in mice.

Epidemiological studies have shown that early life adverse events have long-term effects on the susceptibility to subsequent stress exposure in adolescence, but the precise mechanism is unclear. In the present study, mice on postnatal day 21-28 were randomly assigned to either a group or isolated cages for 8 weeks. The socially isolated (SI) mice exhibited a higher level of spontaneous locomotor activity, a longer duration of immobility in the forced swimming test (FST), significantly less prepulse inhibition (PPI) and an increase in aggressive (but not attack) behavior. However, acute stress markedly exacerbated the attack counts of the SI mice but did not affect the group housing (GH) mice. SI mice exhibited higher synaptosomal NR2A and NR2B levels in the hippocampus as compared to the GH mice. Whole-cell patch clamp recordings of CA1 neurons in hippocampal slices showed that the SI mice exhibited a higher input-output relationship of NMDAR-EPSCs as compared to the GH mice. Application of the NR2B -specific antagonist ifenprodil produced a greater attenuating effect on NMDAR-EPSCs in slices from the SI mice. NMDAR EPSCs recorded from the SI mice had a slower deactivation kinetic. MK-801, CPP and ifenprodil, the NMDA antagonists, reversed acute stress-induced exaggeration of aggressive and depressive behaviors. Furthermore, acute stress-induced exacerbation of attack behavior in the SI mice was abolished after the knockdown of NR2B expression. These results suggest that social isolation-induced increased expression of NMDA receptors in the hippocampus involves stress exacerbation of aggressive behaviors. Amelioration of aggressive behaviors by NMDA antagonists may open a new avenue for the treatment of psychopathologies that involve outbursts of emotional aggression in neglected children.

Development and evaluation of a genetic algorithm-based ocean color inversion model for simultaneously retrieving optical properties and bottom types in coral reef regions.

This work presents a novel approach that integrates a shallow water semi-analytical (SSA) model and a genetic algorithm (GA) to retrieve water column inherent optical properties (IOPs) and identify bottom types simultaneously from measurement of subsurface remote sensing reflectance. This GA-SSA approach is designed based on the assumption that each pixel is homogeneous with regard to the bottom type when viewed at small (centimeter) scales, and it is validated against a synthetic data set (N=11,250) that consists of five types of bottom, three levels of bottom depth, 15 concentrations of chlorophyll-a (Chl-a), and a wide range of modeled IOP variations in clear and optically complex waters representing the coral reef environment. The results indicate that the GA-SSA approach is accurate and robust in the retrieval of IOPs and its success rate in identifying the real bottom type is limited by the level of Chl-a and bottom depth. When a pixel is homogeneous at a small scale, the maximum allowable concentrations for GA-SSA to perfectly identify all the five bottom types are 0.7 mg/m3 at 5 m bottom depth, 0.2 mg/m3 at 10 m, and 0.07 mg/m3 at 15 m. A promising 80% recognition rate of the benthic community is possible with GA-SSA when an underwater hyperspectral imager is deployed to examine the health status of coral reefs in a clean (Chl-a<1 mg/m3) and shallow (bottom depth<10 m) environment. Further study that collects field data for direct validation is required to ensure that the GA-SSA approach is also applicable in real coral reef regions.