Mood and metabolic consequences of sleep deprivation as a potential endophenotype’ in bipolar disorder

It has been commonly recognized that circadian rhythm and sleep/wake cycle are causally involved in bipolar disorder. There has been a paucity of systematic research considering the relations between sleep and mood states in bipolar disorder. The current study examines the possible influences of sleep deprivation on mood states and endocrine functions among first-degree relatives of patients with bipolar disorder and healthy controls. Blood samples were taken at two time points in the consecutive mornings at predeprivation and postdeprivation periods. Participants simultaneously completed the Profiles of Mood States at two time points after giving blood samples. Plasma T3 and TSH levels increased after total sleep deprivation in both groups. Sleep deprivation induced TSH levels were reversely associated with depression–dejection among healthy controls. A paradoxical effect was detected for only the first-degree relatives of the patients that changes in plasma cortisol levels negatively linked to depression–dejection and anger–hostility scores after total sleep deprivation. Plasma DHEA levels became correlated with vigor-activity scores after sleep deprivation among first-degree relatives of bipolar patients. On the contrary, significant associations of depression–dejection, anger–hostility, and confusion–bewilderment with the baseline plasma DHEA levels became statistically trivial in the postdeprivation period. Findings suggested that first-degree relatives of patients with bipolar disorder had completely distinct characteristics with respect to sleep deprivation induced responses in terms of associations between endocrine functions and mood states as compared to individuals whose relatives had no psychiatric problems. Considering the relationships between endocrine functions and mood states among relatives of the patients, it appears like sleep deprivation changes the receptor sensitivity which probably plays a pivotal role on mood outcomes among the first-degree relatives of patients with bipolar disorder.     

Genetic determination of mesencephalic tyrosine hydroxylase activity in the mouse

The hereditary factors that affect mesencephalic tyrosine hydroxylase (TH) activity were investigated in highly inbred mouse strains (CXBI/ByJ, C57BL/6ByJ, and BALB/cJ). The progenitor strains and their F₁ hybrids, were compared for mesencephalic TH activity with each other and with replicated F₂ generations. Quantitative and non-parametric genetic analysis of the data raise the possibility that there is a major gene with robust additive effect that is primarily responsible for the difference between the progenitor strains with intermediate and high mesencephalic TH activity. Strain differences in mesencephalic TH activity have been linked to differences in number of dopamine (DA) neurons in that area. If genetic variation of mesencephalic TH activity is entirely attributable to variation in number of mesencephalic dopamine (DA) neurons, identification of the genetic sources of variation of mesencephalic TH activity may take us a step closer to animal models and preparations that are needed in the study of the physiological and constitutional mechanisms of human disorders in which DA neurotransmission is involved.     

What's wrong with fear conditioning?

Fear conditioning is one of the prime paradigms of behavioural neuroscience and a source of tremendous insight in the fundamentals of learning and memory and the psychology and neurobiology of emotion. It is also widely regarded as a model for the pathogenesis of anxiety disorders in a diathesis-stress model of psychopathology. Starting from the apparent paradox between the adaptive nature of fear conditioning and the dysfunctional nature of pathological anxiety, we present a critique of the human fear conditioning paradigm as an experimental model for psychopathology. We discuss the potential benefits of expanding the human fear conditioning paradigm by (1) including action tendencies as an important index of fear and (2) paying more attention to “weak” (i.e., ambiguous) rather than “strong” fear learning situations (Lissek et al., 2006), such as contained in selective learning procedures. We present preliminary data that illustrate these ideas and discuss the importance of response systems divergence in understanding individual differences in vulnerability for the development of pathological anxiety.     

Reliability of a computer-based neurobehavioral assessment test battery for Bangladeshi adolescent children

In developing countries, there is a need for low-cost neurobehavioral (NB) test batteries for vulnerable populations, particularly for children exposed to environmental neurotoxicants. The objective of the current study was to assess the feasibility and test-retest reliability of the Behavioral Assessment and Research System (BARS) in children from a rural community in Bangladesh. Fifty healthy adolescents living in the Health Effects of Arsenic Longitudinal Study (HEALS) area in Araihazar, Bangladesh completed all six tests from the BARS in two test sessions scheduled two weeks apart. The BARS tests evaluated NB functions such as motor coordination, attention, memory, and information processing speed. The reliability assessment, evaluated by test-retest correlations demonstrated moderate to strong correlations (i.e., correlation coefficients ranged from 0.43 to 0.85), which were statistically significant (p < 0.05). Paired t-tests for comparing the test and retest outcomes indicated significant improvement in NB performance, highlighting learning and practice effects. NB performance improved with increasing age in most cases. Adolescent boys performed better than the girls in Finger Tapping, Digit Span, and Simple Reaction Time, whereas the girls performed better in Continuous Performance and Symbol Digit tests. The reliability scores (Pearson’s correlations 0.43−0.85) were consistent with other children studies in different cultural settings. The effects of age and sex on NB tests were also consistent with findings reported in other countries. Overall, the findings of the study support the feasibility of using this computer-based test system to assess vulnerability of brain health due to environmental exposures among rural Bangladeshi children.     

A Toxicokinetic Study of Nickel‐Induced Immunosuppression in Rats

Abstract

The aim of the present study was to investigate dose‐ and time‐dependent effects of NiCl₂ on T‐lymphocyte and macrophage‐derived cytokine production in rats. Moreover we have determined the concentrations of nickel in the plasma that are required to elicit alterations in T‐lymphocyte and macrophage function. NiCl₂ suppressed T‐lymphocyte proliferation and Th1 (IFN‐γ) and Th2 (IL‐10) cytokine production in a dose‐ and time‐dependent fashion. In addition, NiCl₂ inhibited production of the pro‐inflammatory cytokine TNF‐α and increased production of the anti‐inflammatory cytokine IL‐10 from lipopolysaccharide (LPS) stimulated cultures. We have determined that the minimal plasma concentrations of nickel required to provoke immunosuppression are in the range 209–585 ng/mL. In the time‐course study NiCl₂ (3.3 mg/kg) provoked immunological changes that were maximal 1 h following administration, and some of these changes persisted for up to 24 h post administration. Overall these data clearly demonstrate that NiCl₂ suppresses T‐cell function and promotes an immunosuppressive macrophage phenotype in rats. This study also indicates that measuring T‐cell proliferation is as sensitive a marker of NiCl₂‐induced immunotoxicity as measuring T‐cell or macrophage cytokine production. Co‐measurement of circulating nickel concentrations and immune parameters yields valuable information with regard to the potency of nickel to alter immune function in vivo. These data also suggest that quite a large quantity of nickel needs to reach the systemic circulation before any adverse effects on immune function are observed.     

原发性中枢神经系统血管炎的高分辨率MRI表现

目的探讨HR-MRI对原发性中枢神经系统血管炎(PACNS)的诊断价值。方法分析24例PACNS患者的临床和MRI资料,分析HR-MRI影像学表现。结果在HR-MRI上24例PACNS患者中,存在43个病变,可见管壁环周增厚36个、管壁偏心性增厚7个。管壁内壁均光滑。外壁模糊38个、外壁清晰5个。33个病变可见管壁向心性增强,7个病变管壁偏心性增强,无强化3个。病变累及血管壁的长度中位长度为5.4 mm(范围3.0~7.8 mm),病变部位血管壁厚度的中位厚度为0.69 mm(范围0.52~0.85 mm)。结论高分辨率磁共振成像能够清晰显示受累血管的管壁环周增厚、内壁光滑和外壁模糊、血管壁向心性强化,对PACNS的鉴别诊断有很大的作用。     

The loss of regeneration competency in the animal kingdom at the expense of immunity: A journey in retrospect

Regeneration refers to the structural growth of damaged organs or tissues and their functional integration into the existing system. Injury induced regenerative response is extremely variable across the animal kingdom. On one hand the early acoelomates can reform the entire animal even from dissociated cells, on the other; the capacity in humans is mostly restricted to wound healing. A general trend of regenerative ability is the existence of an inverse relationship between the robustness of immune system and the degree of regeneration throughout the animal kingdom. This review summarizes the evolutionary advancement of immune system in different groups and gives an account of their respective regenerative competency.     

A field-programmable gate array based system for high frame rate laser Doppler blood flow imaging

This paper presents a general embedded processing system implemented in a field-programmable gate array providing high frame rate and high accuracy for a laser Doppler blood flow imaging system. The proposed system can achieve a basic frame rate of flow images at 1 frame/second for 256×256 images with 1024 fast Fourier transform (FFT) points used in the processing algorithm. Mixed fixed-floating point calculations are utilized to achieve high accuracy but with a reasonable resource usage. The implementation has a root mean square deviation of the relative difference in flow values below 0.1% when compared with a double-precision floating point implementation. The system can contain from one or more processing units to obtain the required frame rate and accuracy. The performance of the system is significantly higher than other methods reported to date. Furthermore, a dedicated field-programmable gate array (FPGA) board has been designed to test the proposed processing system. The board is linked with a laser line scanning system, which uses a 64×1 photodetector array. Test results with various operating parameters show that the performance of the new system is better, in terms of noise and imaging speed, than has been previously achieved.