Self-assembly of Ni(II) with a chiral ligand pair vs. mixture of the chiral ligand pair: structural features and recognition ability of Ni2L4 cages

The self-assembly of NiCl2 with a chiral bidentate ligand pair, (1R,2S)-(+)- and (1S,2R)-(-)-1-(nicotinamido)-2,3-dihydro-1H-inden-2-yl nicotinate (r,s-L and s,r-L) in a mixture of ethanol and dioxane, gives rise to stable crystals consisting of [2Cl@Ni2Cl2(s,r-L)4(H2O)2]·4C4H8O2·EtOH and [2Cl@Ni2Cl2(r,s-L)4(H2O)2]·4C4H8O2·EtOH chiral cages, respectively, with two encapsulated chloride anions in the cavities. The most interesting feature is that the self-assembly of NiCl2 with the mixture of r,s-L and s,r-L (1 : 1-1 : 4) produces crystals of thermodynamically stable achiral cages, [2Cl·2H2O@Ni2Cl2(s,r-L)2(r,s-L)2(H2O)2]·7C4H8O2, in the molar ratio range. Furthermore, the [2Cl@Ni2Cl2(s,r-L)4(H2O)2]·4C4H8O2·EtOH and [2Cl@Ni2Cl2(r,s-L)4(H2O)2]·4C4H8O2·EtOH chiral crystals can recognize the pairs of L-,D-tryptophan and L-,D-cysteine via cyclic voltammetry (CV) signals, in contrast to the [2Cl·2H2O@Ni2Cl2(s,r-L)2(r,s-L)2(H2O)2]·7C4H8O2 achiral crystal.

Formation Process of SiF6@Cu2L4 Chiral Cage Pairs in a Glass Vessel: Catechol Oxidation Catalysis and Chiral Recognition

Self-assembly of CuX2 (X- = BF4-, PF6-, and SbF6-) with a pair of chiral bidentate ligands, (1R,2S)-(+)- and (1S,2R)-(-)-1-(nicotinamido)-2,3-dihydro-1H-inden-2-yl-nicotinate (r,s-L or s,r-L), in a mixture solvent including ethanol in a glass vessel gives rise to SiF62--encapsulated Cu2L4 chiral cage products. The SiF62- anion from the reaction of X- with SiO2 of the glass-vessel surface acts as a cage template or cage bridge. One of the products, [SiF6@Cu2(SiF6)(s,r-L)4]·3CHCl3·4EtOH, is one of the most effective heterogeneous catalysts for the oxidation of 3,5-di-tert-butylcatechol. Furthermore, an l-DOPA/d-DOPA pair is recognizable by the cyclic voltammetry (CV) signals of its combination with chiral cages [SiF6@Cu2(BF4)2(s,r- or r,s-L)4]·4CHCl3·2EtOH pair and [SiF6@Cu2(SiF6)(s,r- or r,s-L)4]·3CHCl3·4EtOH pair.

Association of immunotoxicological indices with lung cancer biomarkers in poultry, grape, and rose farming workers

Exposure to occupational hazards like dust, pesticides, diesel emission particles, or physical hazards in the agricultural sector is known to cause adverse health effects on farm workers. Our study aimed at addressing the association of immunomodulatory status with plasma levels of lung cancer biomarkers in farming population, attempting to recognition of vulnerable farming group. Blood samples from apparently healthy 51 chicken husbandry, 19 grape orchard, and 21 rose greenhouse workers were subjected to evaluate plasma levels of two representative lung cancer biomarkers, pro-gastrin releasing peptide (Pro-GRP) and cytokeratin fragment 19 (CYFRA 21-1). Peripheral blood mononuclear cells obtained from farmers were used for natural killer (NK) cell phenotyping and cytokines (interferon-gamma, IFN-γ and interleukin-13, IL-13) profiling in the culture supernatant. Compared to the rose greenhouse farmers, the grape orchard and chicken husbandry workers revealed a significantly upregulated plasma Pro-GRP and CYFRA 21-1 level. A low proportion of NK cells was observed among the female grape orchard workers and a lowered IFN- γ:IL-13 ratio was seen in the grape and chicken husbandry workers than the rose workers. Our findings imply that grape orchard and chicken husbandry workers have more disturbed immune homeostasis implicated with augmentation in the levels of lung cancer biomarkers than the rose greenhouse workers.

Dopamine and serotonin alterations by Hizikia fusiformis extracts under in vitro cortical primary neuronal cell cultures

BACKGROUND/OBJECTIVES

Hizikia fusiformis (HF) is a class of brown seaweeds whose active ingredients exert central nervous system protective effects, such as neuroprotection; however, the underlying mechanisms remain unknown. Given that dopamine (DA) and serotonin (5HT) are two major neurotransmitters involved in various psychiatric disorders and neuronal growth in early neurodevelopmental processes, we investigated whether HF extract could modulate the molecular expression associated with DA and 5HT transmission as well as the structural formation of neurons.

MATERIALS/METHODS

In vitro cell cultures were prepared from cerebral cortical neurons obtained from CD-1 mice on embryonic day 14. Cultured cells were treated with 0.1, 1.0, or 10.0 μg/mL of HT extract for 24 h, followed by fluorescence immunostaining for DA and 5HT-related receptors and transporters and some neuronal structural formation-associated molecules.

RESULTS

HF extract dose-dependently upregulated the expression levels of selective DA and 5HT receptors, and downregulated the levels of DA and 5HT transporters. Moreover, HF extract increased the neurofilament light chain expression.

CONCLUSION

These results suggest that HF may modulate DA and 5HT transmission, thereby affecting neurodevelopment.

Pair of chiral 2D silver(I) enantiomers: chiral recognition of L- and D-histidine via differential pulse voltammetry

Self-assembly of AgPF₆ with a pair of chiral tridentate ligands (1S,1'S,1''S,2R,2'R,2''R) and (1R,1'R,1''R,2S,2'S,2''S)-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl)triisonicotinate (s,r-L) and (r,s-L) in a mixture of methanol and dioxane yields 2D sheets consisting of [Ag(s,r-L)](PF₆)·3C₄H₈O₂·0.5H₂O and [Ag(r,s-L)](PF₆)·3C₄H₈O₂·0.5H₂O, respectively. The differential pulse voltammetric (DPV) technique using the pair of chiral 2D-sheet enantiomers was employed for chiral discrimination of amino acid enantiomers, and was found to be an effective tool for enantio-recognition of L- and D-histidines. Both the size and the binding site of amino acids were strongly dependent on electrochemical enantio-recognition via the chiral 2D sheets.

The Habenula in the Link Between ADHD and Mood Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset, neurodevelopmental disorder, whereas major depressive disorder (MDD) is a mood disorder that typically emerges in adulthood. Accumulating evidence suggests that these seemingly unrelated psychiatric disorders, whose symptoms even appear antithetical [e.g., psychomotor retardation in depression vs. hyperactivity (psychomotor acceleration) in ADHD], are in fact associated with each other. Thus, individuals with ADHD exhibit high comorbidity with MDD later in life. Moreover, genetic studies have shown substantial overlaps of susceptibility genes between ADHD and MDD. Here, we propose a novel and testable hypothesis that the habenula, the epithalamic brain region important for the regulation of monoamine transmission, may be involved in both ADHD and MDD. The hypothesis suggests that an initially hypoactive habenula during childhood in individuals with ADHD may undergo compensatory changes during development, priming the habenula to be hyperactive in response to stress exposure and thereby increasing vulnerability to MDD in adulthood. Moreover, we propose a new perspective on habenular deficits in psychiatric disorders that consider the habenula a neural substrate that could explain multiple psychiatric disorders.

Alterations of amygdala-prefrontal cortical coupling and attention deficit/hyperactivity disorder-like behaviors induced by neonatal habenula lesion: normalization by Ecklonia stolonifera extract and its active compound fucosterol

Alterations of monoamine transmission in mesocorticolimbic regions have been suggested in the pathophysiology of attention deficit/hyperactivity disorder (ADHD). The habenula is an important brain area in regulation of monoamine transmission. In this study, we investigated behavioral and electrophysiological alterations induced by neonatal habenula lesion (NHL) in rats. In NHL rats, age-dependent behavioral alterations relevant to the ADHD symptoms, such as hyperlocomotion, impulsivity, and attention deficit, were observed. Local field potentials (LFPs) in mesocorticolimbic regions of anesthetized rats were examined with in vivo electrophysiological recordings. Abnormally enhanced synchronization of slow (delta) and fast (gamma) LFP oscillations between the amygdala (AMY) and prefrontal cortex (PFC) was found in juvenile, but not in adult, NHL rats. We further examined the effects of an extract and the active compound from the perennial large brown algae Ecklonia stolonifera (ES), which have previously been demonstrated to modulate monoamine transmission, on these NHL-induced alterations. One week of ES extract treatments normalized the NHL-induced behavioral alterations, whereas the active compound fucosterol improved attention deficit and impulsivity, but not hyperlocomotion, in NHL rats. Consistent with the behavioral effects, ES extract treatments also normalized augmented AMY-PFC coupling. These results suggest that altered limbic-cortical information processing may be involved in ADHD-like behavioral alterations induced by NHL, which could be ameliorated by the natural substance, such as ES that affects monoamine transmission.

Cognitive and Affective Processes Associated with Social Biases

BACKGROUND

Our social activities are quite often erroneous and irrational, based on biased judgements and decision-making, known as social biases. However, the cognitive and affective processes that produce such biases remain largely unknown. In this study, we investigated associations between social schemas, such as social judgment and conformity, entailing social biases and psychological measurements relevant to cognitive and affective functions.

METHOD

This study recruited 42 healthy adult subjects. A psychological test and a questionnaire were administered to assess biased social judgements by superficial attributes and social conformity by adherence to social norms, respectively, along with additional questionnaires and psychological tests for cognitive and affective measurements, including negative affects, autistic traits, and Theory of Mind (ToM). Associations of social judgment and conformity with cognitive and affective functions were examined using a multiple regression analysis and structural equation modeling.

RESULTS

Anxiety and the cognitive realm of ToM were mutually associated with both social judgments and conformity, although social judgements and conformity were still independent processes. Social judgements were also associated with autistic traits and the affective realm of ToM, whereas social conformity was associated with negative affects other than anxiety and an intuitive decision-making style.

CONCLUSIONS

These results suggest that ToM and negative affects may play important roles in social judgements and conformity, and the social biases connoted in these social schemas.

Supramolecular isomerism between cyclodimeric and sinusoidal 1D coordination polymers: competition of tunable argentophilic vs. electrostatic interactions

Anion exchanges of metallacyclodimeric nitrate to polyatomic anions crystallize in situ, resulting in a systematic supramolecular isomerism to 1D coordination polymers in mother liquor.

Flexibility and anion exchange of [(X)@Pd2L4] cages for recognition of size and charge of polyatomic anions

The self-assembly of Pd(NO3)2 with L (L = 1,2-bis(dimethyl(pyridin-3-yl)silyl)ethane) gives rise to [PdL2](NO3)2 in high yields. Anion exchange of [PdL2](NO3)2 with X- (X- = BF4-, ClO4-, and PF6-) changes the skeleton into a cage of [(X)@Pd2L4](X)3. Successive anion exchange of [(X)@Pd2L4](X)3 (X- = BF4-, ClO4-, and PF6-) with X- (X- = ReO4- and SiF62-) produces [(ReO4)@Pd2L4](ReO4)3 and [(SiF6)@Pd2L4](SiF6), respectively, irrespective of anion charge. The flexible nature and conformation of cages are significantly dependent on the nestled polyatomic anions. Thus, this system can be used as a molecular recognizer of the size and charge of ubiquitous polyatomic anions.

Monoamine and genome-wide DNA methylation investigation in behavioral addiction

Behavioral addiction (BA) is characterized by repeated, impulsive and compulsive seeking of specific behaviors, even with consequent negative outcomes. In drug addiction, alterations in biological mechanisms, such as monoamines and epigenetic processes, have been suggested, whereas whether such mechanisms are also altered in BA remains unknown. In this preliminary study with a small sample size, we investigated monoamine concentrations and genome-wide DNA methylation in blood samples from BA patients and control (CT) subjects. Higher dopamine (DA) metabolites and the ratio between DA and its metabolites were observed in the BA group than in the CT group, suggesting increased DA turnover in BA. In the methylation assay, 186 hyper- or hypomethylated CpGs were identified in the BA group compared to the CT group, of which 64 CpGs were further identified to correlate with methylation status in brain tissues with database search. Genes identified with hyper- or hypomethylation were not directly associated with DA transmission, but with cell membrane trafficking and the immune system. Some of the genes were also associated with psychiatric disorders, such as drug addiction, schizophrenia, and autism spectrum disorder. These results suggest that BA may involve alterations in epigenetic regulation of the genes associated with synaptic transmission, including that of monoamines, and neurodevelopment.

Concurrent and Delayed Behavioral and Monoamine Alterations by Excessive Sucrose Intake in Juvenile Mice

Our daily diet in the modern society has substantially changed from that in the ancient past. Consequently, new disorders associated with such dietary changes have emerged. For instance, excessive intake of compounds, such as sucrose (SUC), has recently been reported to induce pathological neuronal changes in adults, such as food addiction. It is still largely unclear whether and how excessive intake of such nutrients affects neurodevelopment. We investigated changes in behavior and monoamine signaling caused by excessive, semi-chronic intake of SUC and the non-caloric sweetener saccharin (SAC) in juvenile mice, using a battery of behavioral tests and high-performance liquid chromatography. Both SUC and SAC intake induced behavioral alterations such as altered amphetamine responses, sucrose preference, stress response, and anxiety, but did not affect social behavior and cognitive function such as attention in juvenile and adult mice. Moreover, SUC and SAC also altered dopamine and serotonin transmission in mesocorticolimbic regions. Some of these behavioral and neural alterations were triggered by SAC and SUC but others were distinct between the treatments. Moreover, alterations induced in juvenile mice were also different from those observed in adult mice. These results suggest that excessive SUC and SAC intake during the juvenile period may cause concurrent and delayed behavioral and monoamine signaling alterations in juvenile and adult mice, respectively.

Hexafluorosilicate anion in the formation of a coordination cage: anion competition

The construction of a coordination cage in a system of dual anions including hexafluorosilicate was investigated. Significant catalytic effects on catechol oxidation catalysis performance ranks among the most efficient yet recorded.

Gerontological education: Course and experiential differences across academic colleges

A knowledgeable workforce is key to meeting the demands of an aging population that is expected to nearly triple by 2030 and their attitudes influence propensity to seek aging-related careers. Postsecondary education offers an opportunity to increase aging-related knowledge and facilitates intergenerational experiential-learning opportunities; however, research is lacking regarding attitudes toward aging and experiences among an academically diverse sample. To address this gap, the aims of this study were to (1) examine differences in students' attitudes toward older adults by academic college, (2) assess differences in aging-related coursework and course experiences by academic college, and (3) explore key factors associated with students' attitudes toward older adults. Online survey methodology was used with a sample of 816 undergraduate students from a single university who represented all academic colleges offering undergraduate degrees. Significant differences among students' attitudes toward older adults by academic college were noted: those enrolled in the College of Human Sciences reported better stereotype, separation, and affective attitudes. Furthermore, factors associated with students' aging-related attitudes were sex, affiliation with academic college, perception of "old," contact frequency, and desire to learn aging-related content. The authors suggest interdisciplinary and disciplinary-specific educational recommendations to improve students' attitudes toward older adults.

Adsorption of anthracene substitutes into suprachannels: bulk vs. included guests

Investigation of FRET of included anthracene substitutes within unusual hydrophobic suprachannels was carried out.

The Roles of Serotonin in Decision-making under Social Group Conditions

People in a social group often have to make decisions under conflict, for instance, to conform to the group or obey authority (subjects at higher social rank in the group). The neural mechanisms underlying how social group setting affects decision-making have largely remained unclear. In this study, we designed novel behavioral tests using food access priority and fear conditioning paradigms that captured decision-making under conflict associated with social group environments in mice and examined the roles of serotonin (5-HT) on these processes. Using these behavioral tests, administration of the selective 5-HT reuptake inhibitor, which increased 5-HT transmission, was found to attenuate conflicts in decision-making that may be associated with human cases of social obedience and conformity in mice under group housing. The results suggest that 5-HT plays important roles in the regulation of individual behaviors that organize social group dynamics.

Dopamine-dependent visual attention preference to social stimuli in nonhuman primates

RATIONALE

Dopamine (DA) plays a central role in reward processing. Accumulating evidence suggests that social interaction and social stimuli have rewarding properties that activate the DA reward circuits. However, few studies have attempted to investigate how DA is involved in the processing of social stimuli.

OBJECTIVES

In this study, we investigated the effects of pharmacological manipulations of DA D1 and D2 receptors on social vs. nonsocial visual attention preference in macaques.

METHODS

Japanese macaques were subjected to behavioral tests in which visual attention toward social (monkey faces with and without affective expressions) and nonsocial stimuli was examined, with D1 and D2 antagonist administration.

RESULTS

The macaques exhibited significantly longer durations of gazing toward the images with social cues than did those with nonsocial cues. Both D1 and D2 antagonist administration decreased duration of gazing toward the social images with and without affective valences. In addition, although D1 antagonist administration increased the duration of gazing toward the nonsocial images, D2 antagonism had no effect.

CONCLUSIONS

These results suggest that both D1 and D2 receptors may have roles in the processing of social signals but through separate mechanisms.

The Roles of Dopamine D1 Receptor on the Social Hierarchy of Rodents and Nonhuman Primates

BACKGROUND

Although dopamine has been suggested to play a role in mediating social behaviors of individual animals, it is not clear whether such dopamine signaling contributes to attributes of social groups such as social hierarchy.

METHODS

In this study, the effects of the pharmacological manipulation of dopamine D1 receptor function on the social hierarchy and behavior of group-housed mice and macaques were investigated using a battery of behavioral tests.

RESULTS

D1 receptor blockade facilitated social dominance in mice at the middle, but not high or low, social rank in the groups without altering social preference among mates. In contrast, the administration of a D1 receptor antagonist in a macaque did not affect social dominance of the drug-treated animal; however, relative social dominance relationships between the drug-treated and nontreated subjects were altered indirectly through alterations of social affiliative relationships within the social group.

CONCLUSIONS

These results suggest that dopamine D1 receptor signaling may be involved in social hierarchy and social relationships within a group, which may differ between rodents and primates.

Prefrontal cortical activity associated with visual stimulus categorization in non-human primates measured with near-infrared spectroscopy

In biomedical research of brain dysfunction in psychiatric disorders, utilization of animal models is essential. However, translation of findings in animal models into the realm of human clinical conditions requires reliable biomarkers that are assessed with the methods mutually employed in animal models and human patients. Near-infrared spectroscopy (NIRS) is a functional neuroimaging technique that has now been widely utilized in human basic and clinical research. However, its application to animal models has been barely conducted. In this study, we developed the method to measure neural activity in the cortex of Japanese macaques using NIRS, and examined cortical responses to presentation of a set of visual stimuli that were categorized into four different groups (flower, monkey, snake, food). Prefrontal cortical (PFC) oxy- and deoxy-hemoglobin changes were found to reliably distinguish the categories of these visual stimuli. The results suggest that cortical activity measurement with NIRS in primates can be a valuable model for identifying biomarkers associated with psychiatric disorders.

Biological mechanisms underlying evolutionary origins of psychotic and mood disorders

Psychotic and mood disorders are brain dysfunctions that are caused by gene environment interactions. Although these disorders are disadvantageous and involve behavioral phenotypes that decrease the reproductive success of afflicted individuals in the modern human society, the prevalence of these disorders have remained constant in the population. Here, we propose several biological mechanisms by which the genes associated with psychotic and mood disorders could be selected for in specific environmental conditions that provide evolutionary bases for explanations of when, why, and where these disorders emerged and have been maintained in humans. We discuss the evolutionary origins of psychotic and mood disorders with specific focuses on the roles of dopamine and serotonin in the conditions of social competitiveness/hierarchy and maternal care and other potential mechanisms, such as social network homophily and symbiosis.

Association between catechol-O-methyl transferase gene polymorphisms and fibromyalgia in a Korean population: A case-control study

BACKGROUND

Although polymorphisms of the catechol-O-methyl transferase (COMT) gene have been implicated in altered pain sensitivity, results concerning the association between COMT gene polymorphisms and fibromyalgia (FM) are equivocal. We assessed the associations between COMT single-nucleotide polymorphisms (SNP) and FM risk and symptom severity.

METHODS

In total, 409 FM patients and 423 controls were enrolled. Alleles and genotypes at five positions [rs6269 (A>G), rs4633 (C>T), rs4818 (C>G), rs4680 (C>G) and rs165599 (A>G)] in the COMT gene were genotyped from peripheral blood DNA.

RESULTS

Alleles and genotypes of the rs4818 COMT gene polymorphism were significantly associated with increased susceptibility to FM. The rs4818 GG genotype was more strongly associated with FM compared to the CC genotype (OR = 1.680, 95% CI: 1.057, 2.672, p = 0.027). Although allele and genotype frequencies did not differ among groups, the rs4633 CT genotype was not associated with the presence of FM following adjustment for age and sex (OR = 0.745; 95% CI: 0.558, 0.995; p = 0.046). However, no association was observed between clinical measures and individual COMT SNPs. In haplotype analysis, there was a significant association between ACG haplotype and FM susceptibility sex (OR = 2.960, 95% CI: 1.447, 6.056, p = 0.003) and the number of tender points (p = 0.046).

CONCLUSIONS

This large-scale study suggests that polymorphisms of the COMT gene may be associated with FM risk and pain sensitivity in Korean FM patients. However, our results differed to those of previous studies, suggesting ethnic variation in COMT gene polymorphisms in FM.

WHAT DOES THIS STUDY ADD

By contrast to Caucasian and Latin-American populations, the COMT gene polymorphisms are associated with FM risk and pain sensitivity in Korean FM patients, suggesting ethnic variation in COMT gene polymorphisms.

Photoreaction of adsorbed diiodomethane: halide effects of a series of neutral palladium(ii) coordination cages

The synthetic aspect of a series of [Pd₆X₁₂L₄] (X⁻ = Cl⁻, Br⁻, I⁻) cages, including Br/I replacement reaction and halide effects on physicochemical properties, adsorption of CH₂I₂, and photo-cyclopropanation, has been investigated.

Dopamine in socioecological and evolutionary perspectives: implications for psychiatric disorders

Dopamine (DA) transmission in brain areas such as the prefrontal cortex (PFC) and nucleus accumbens (NAcc) plays important roles in cognitive and affective function. As such, DA deficits have been implicated in a number of psychiatric disorders such as schizophrenia and attention deficit/hyperactivity disorder (ADHD). Accumulating evidence suggests that DA is also involved in social behavior of animals and humans. Although most animals organize and live in social groups, how the DA system functions in such social groups of animals, and its dysfunction causes compromises in the groups has remained less understood. Here we propose that alterations of DA signaling and associated genetic variants and behavioral phenotypes, which have been normally considered as “deficits” in investigation at an individual level, may not necessarily yield disadvantages, but even work advantageously, depending on social contexts in groups. This hypothesis could provide a novel insight into our understanding of the biological mechanisms of psychiatric disorders, and a potential explanation that disadvantageous phenotypes associated with DA deficits in psychiatric disorders have remained in humans through evolution.

Chronic stress effects on working memory: association with prefrontal cortical tyrosine hydroxylase

Chronic stress causes deficits in cognitive function including working memory, for which transmission of such catecholamines as dopamine and noradrenaline transmission in the prefrontal cortex (PFC) are crucial. Since catecholamine synthesis depends on the rate-limiting enzyme, tyrosine hydroxylase (TH), TH is thought to play an important role in PFC function. In this study, we found that two distinct population existed in Sprague-Dawley rats in terms of working memory capacity, one with higher working memory capacity, and the other with low capacity. This distinction of working memory capacity became apparent after rats were exposed to chronic stress. In addition, such working memory capacity and alterations of working memory function by chronic stress were associated with TH expression in the PFC.

Prefrontal cortical dopamine from an evolutionary perspective

In this article, we propose the hypothesis that the prefrontal cortex (PFC) acquired neotenic development as a consequence of mesocortical dopamine (DA) innervation, which in turn drove evolution of the PFC into becoming a complex functional system. Accordingly, from the evolutionary perspective, decreased DA signaling in the PFC associated with such adverse conditions as chronic stress may be considered as an environmental adaptation strategy. Psychiatric disorders such as schizophrenia and attention deficit/hyperactivity disorder may also be understood as environmental adaptation or a by-product of such a process that has emerged through evolution in humans. To investigate the evolutionary perspective of DA signaling in the PFC, domestic animals such as dogs may be a useful model.

Reconsideration of animal models of schizophrenia and other psychiatric disorders with evolutionary perspective

Studies utilizing animal models for understanding biological mechanisms of such psychiatric disorders as schizophrenia have been now flourishing. Animal models are a essential part of translational research, and without them, it is not possible to develop therapeutic strategies to treat psychiatric disorders. Accordingly, importance of animal models has been increasingly emphasized. However, on the other side, limitations of such an animal model approach have been growingly deceptive. The aim of this review article is to discuss limitations of translational research utilizing animal models, and propose a new direction of research with evolutionary perspective to understand psychiatric disorders.

Risk factors for osteoporosis in long-term survivors of intracranial germ cell tumors

SUMMARY

We measured bone mineral densities in 28 intracranial germ cell tumor long-term survivors. There was the high prevalence of osteoporosis and osteopenia, 25.0% and 42.9%, respectively, and three additional risk factors, male sex, a low lean mass, and adult growth hormone replacement, were identified.

INTRODUCTION

Intracranial germ cell tumor long-term survivors (iGCTLS) have many risk factors for osteoporosis, including irradiation from cancer therapy and multiple hormone deficiencies. However, no study of bone mineral density (BMD) has been conducted in iGCTLS because these tumors are rare. The aims of this study were to evaluate the prevalence of osteoporosis and to identify risk factors associated with reduced bone mass in iGCTLS.

METHODS

We evaluated BMD and body composition of 28 iGCTLS (10.9 ± 5.2 years after cancer treatment; 13 males) using dual-energy X-ray absorptiometry. To determine risk factors, we analyzed the medical history, including the nature of the tumor, treatment modality, endocrine status, hormone replacement therapy, lifestyle, and biochemical parameters.

RESULTS

Twenty-five percent of iGCTLS were diagnosed with osteoporosis and 42.9% with osteopenia. Most males (92.3%) had low BMD. Lean mass (LM) was positively correlated with BMD in all regions of interest, and the starting age of adult growth hormone (GH) replacement was negatively correlated with the BMD Z-score at the femur neck. In logistic regression analysis, male sex and low LM were related to low BMD.

CONCLUSIONS

The iGCTLS had a high prevalence of low BMD. We found that male sex, low LM, and delayed start of adult GH replacement were risk factors for osteoporosis. Therefore, the BMD of all iGCTLS should be evaluated, and if it is low, proper management should be started early.

Reactive oxygen species-dependent necroptosis in Jurkat T cells induced by pathogenic free-living Naegleria fowleri

Naegleria fowleri, a free-living amoeba, is the causative pathogen of primary amoebic meningoencephalitis in humans and experimental mice. N. fowleri is capable of destroying tissues and host cells through lytic necrosis. However, the mechanism by which N. fowleri induces host cell death is unknown. Electron microscopy indicated that incubation of Jurkat T cells with N. fowleri trophozoites induced necrotic morphology of the Jurkat T cells. N. fowleri also induced cytoskeletal protein cleavage, extensive poly (ADP-ribose) polymerase hydrolysis and lactate dehydrogenase (LDH) release. Although no activation of caspase-3 was observed in Jurkat T cells co-incubated with amoebae, intracellular reactive oxygen species (ROS) were strongly generated by NADPH oxidase (NOX). Pretreating cells with necroptosis inhibitor necrostatin-1 or NOX inhibitor diphenyleneiodonium chloride (DPI) strongly inhibited amoeba-induced ROS generation and Jurkat cell death, whereas pan-caspase inhibitor z-VAD-fmk did not. N. fowleri-derived secretory products (NfSP) strongly induced intracellular ROS generation and cell death. Necroptotic effects of NfSP were effectively inhibited by pretreating NfSP with proteinase K. Moreover, NfSP-induced LDH release and intracellular ROS accumulation were inhibited by pretreating Jurkat T cells with DPI or necrostatin-1. These results suggest that N. fowleri induces ROS-dependent necroptosis in Jurkat T cells.

Calpain mediates degradation of cytoskeletal proteins during Jurkat T-cell death induced by Entamoeba histolytica

Entamoeba histolytica is known to induce host cell death via activation of calpain and caspases. In this study, we investigated the specific proteases involved in the degradation of cytoskeletal proteins during Jurkat T-cell death induced by E. histolytica. Amoebic trophozoites induced marked degradation of paxillin, Cas, vimentin, vinculin and talin, as well as α- or β-spectrin, in Jurkat T cells. The cleavage effects of E. histolytica were strongly retarded by pretreatment with a calpain inhibitor, but not with a pan-caspase inhibitor. In addition, calpain knockdown with siRNA in Jurkat T cells effectively inhibited E. histolytica-induced PARP, paxillin, α-spectrin, β-spectrin and talin degradation, as compared to scrambled siRNA. These results suggest that calpain plays a crucial role in the cleavage of cytoskeletal proteins during cell death induced by E. histolytica.

Is schizophrenia developmental adaptation to environmental menaces?

Schizophrenia is a devastating mental disorder, with its symptoms typically emerging during late adolescence to young adulthood. In contrast, accumulating evidence suggests that schizophrenia is a developmental disorder in which brain abnormalities may occur even before birth. This has brought the major challenge to explain such discrepancy of brain deficits occurring during prenatal period and emergence of symptoms during adulthood. A number of ideas have been proposed to explain delayed emergence of symptoms at adulthood in relation to maturational processes of various brain systems during adolescence. However, these still lack clear relationship to prenatal deficits. Thus, a key to better understand the pathology of schizophrenia is to unveil a theory or model that can explain the relationship between prenatal deficits and post-pubertal onset of symptoms. Here we propose a novel hypothesis, along with discussion of several lines of evidences supporting it, that schizophrenia may not be a disorder in a strict sense, but rather be understood as the biological state occurring as consequence of adaptation to severe environmental conditions during the prenatal periods, which explains the relationship between prenatal developmental deficits and the postnatal maturational process for onset of symptoms.

Chronic stress modulation of prefrontal cortical NMDA receptor expression disrupts limbic structure-prefrontal cortex interaction

Chronic stress causes various detrimental effects including cognitive and affective dysfunctions. Given the recent findings emphasizing the importance of information processing between the prefrontal cortex (PFC) and limbic structures on cognitive and affective functions, impairments of these functions caused by chronic stress may be associated with stress-induced adaptive and maladaptive responses in limbic structure-PFC interaction. In this study we have shown that chronic stress disrupts limbic structure-PFC interaction by modulating N-methyl-D-aspartate (NMDA) receptor expression in the PFC. We found that chronic stress decreased expression of NR1, NR2A and NR2B subunits of NMDA receptors in the PFC but not in the motor cortex. However, the reduction in NR2B subunits of NMDA receptors was larger in the dorsal part than the ventral part of PFC. In agreement with this observation, administration of the NMDA antagonist that was more selective for NMDA receptors containing NR2B subunits induced alterations of synchronous local field potentials between the PFC and limbic structures, synaptic plasticity induction in the limbic structure-PFC pathway, and spike firing of PFC neurons that were similar to those observed in the dorsal PFC of rats exposed to chronic stress. In contrast, administration of the NMDA antagonist that was not subunit-selective resulted in electrophysiological alterations resembling to those observed in the ventral PFC of rats exposed to chronic stress. These results suggest that chronic stress disrupts NMDA receptor-dependent limbic structure-PFC information processing.

Neurodevelopmental disruption of cortico-striatal function caused by degeneration of habenula neurons

Background

The habenula plays an important role on cognitive and affective functions by regulating monoamines transmission such as the dopamine and serotonin, such that its dysfunction is thought to underlie a number of psychiatric conditions. Given that the monoamine systems are highly vulnerable to neurodevelopmental insults, damages in the habenula during early neurodevelopment may cause devastating effects on the wide-spread brain areas targeted by monoamine innervations.

Methodology/Principal Findings

Using a battery of behavioral, anatomical, and biochemical assays, we examined the impacts of neonatal damage in the habenula on neurodevelopmental sequelae of the prefrontal cortex (PFC) and nucleus accumbens (NAcc) and associated behavioral deficits in rodents. Neonatal lesion of the medial and lateral habenula by ibotenic acid produced an assortment of behavioral manifestations consisting of hyper-locomotion, impulsivity, and attention deficit, with hyper-locomotion and impulsivity being observed only in the juvenile period, whereas attention deficit was sustained up until adulthood. Moreover, these behavioral alterations were also improved by amphetamine. Our study further revealed that impulsivity and attention deficit were associated with disruption of PFC volume and dopamine (DA) receptor expression, respectively. In contrast, hyper-locomotion was associated with decreased DA transporter expression in the NAcc. We also found that neonatal administration of nicotine into the habenula of neonatal brains produced selective lesion of the medial habenula. Behavioral deficits with neonatal nicotine administration were similar to those caused by ibotenic acid lesion of both medial and lateral habenula during the juvenile period, whereas they were different in adulthood.

Conclusions/Significance

Because of similarity between behavioral and brain alterations caused by neonatal insults in the habenula and the symptoms and suggested neuropathology in attention deficit/hyperactivity disorder (ADHD), these results suggest that neurodevelopmental deficits in the habenula and the consequent cortico-striatal dysfunctions may be involved in the pathogenesis and pathophysiology of ADHD.