Relationship between hypothalamic-pituitary-adrenal axis dysregulation and insulin resistance in elderly patients with depression.

Cortisol dysregulation has been proposed to be involved in depression. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with major depressive disorder (MDD) was previously reported to be higher in the elderly. Furthermore, insulin resistance and the prevalence of type 2 diabetes are known to increase with aging.

Association between social functioning and prefrontal hemodynamic responses in elderly adults.

Social functioning has received widespread attention as one of the most important outcomes in psychiatric disorders and has been related to cognitive functioning and the underlying brain activity. Cognitive decline, however, appears not only in the psychiatric population but also in aged individuals. In our previous study, we demonstrated a significant relationship between social functioning and prefrontal cortex (PFC) activity in patients with depression.

Relationship between prefrontal function during a cognitive task and social functioning in male Japanese workers: a multi-channel near-infrared spectroscopy study.

To investigate whether prefrontal function during a cognitive task reflects the social functioning of male Japanese workers, prefrontal function during a working memory task in 181 male workers was measured by multi-channel near-infrared spectroscopy (NIRS). Social functioning was assessed using the Social Adaptation Self-Evaluation Scale (SASS). The results indicated that cortical oxygenation level increases in dorsolateral prefrontal region showed significant positive correlations with the interest and motivation factor scores on the SASS.

Reduced prefrontal cortex activation during the working memory task associated with poor social functioning in late-onset depression: multi-channel near-infrared spectroscopy study.

A number of studies have demonstrated impairment of working memory (WM) in patients with major depressive disorder (MDD). However, the relationship between the underlying brain activity associated with impairment of WM function in MDD patients and their clinical characteristics is not yet clear. The objective of this study is to evaluate prefrontal hemodynamic response related to a WM task in patients with late-onset depression (LOD) and to assess the relationship between activation in the prefrontal cortex and clinical characteristics.

The relationship between the prefrontal activation during a verbal fluency task and stress-coping style in major depressive disorder: a near-infrared spectroscopy study.

This study aimed to identify coping styles used by patients with major depressive disorder (MDD) in comparison with those used by healthy controls, and to explore their association with prefrontal hemodynamic response related to a cognitive task. Regional hemodynamic changes were monitored during a verbal fluency task (VFT) using a 52-channel near-infrared spectroscopy (NIRS) apparatus in 26 MDD patients in depressive state and 30 matched healthy controls, and their correlation with coping styles assessed by Coping Inventory for Stressful Situations (CISS) were examined. We found the Emotion-oriented coping style was significantly higher, whereas the Task-oriented coping and Avoidance-oriented coping style were lower in the MDD group compared with controls.

Fish consumption is positively associated with social functioning: a cross-sectional study in male Japanese workers.

This study investigated the association of fish consumption with social functioning. One hundred forty male Japanese workers completed the social adaptation self-evaluation scale (SASS) and their customary fish consumption was assessed. The total, interest, and motivation factor scores on SASS showed significant positive correlations with fish consumption.

A multi-channel near-infrared spectroscopy study of prefrontal cortex activation during working memory task in major depressive disorder.

Many neuropsychological studies demonstrate impairment of working memory in patients with major depressive disorder (MDD). However, there are not enough functional neuroimaging studies of MDD patients seeking for the underlying brain activity relevant to working memory function. The objective of this study is to evaluate prefrontal hemodynamic response related to working memory function in patients with MDD.

Reduced frontopolar activation during verbal fluency task associated with poor social functioning in late-onset major depression: Multi-channel near-infrared spectroscopy study.

Aim: Functional neuroimaging studies to date have indicated prefrontal dysfunction in late-onset major depression (LOD). The relationships between prefrontal dysfunction and clinical characteristics including social functioning, however, have been unclear. The objective of the present study was to evaluate prefrontal hemodynamic response related to an executive task in LOD and to assess the relationship between activation in the prefrontal regions and clinical characteristics including social functioning.

Individual and additive effects of neuromodulators on the slow components of afterhyperpolarization currents in layer V pyramidal cells of the rat medial prefrontal cortex.

The effects of 5-hydroxytryptamine (5-HT), noradrenaline (NA), dopamine (DA) and the muscarinic receptor agonist carbachol (CCh) on the voltage step-induced outward currents underlying afterhyperpolarization (AHP), consisting of a medium (I(mAHP)) and slow (I(sAHP)) component, were investigated in layer V pyramidal cells of the rat medial prefrontal cortex (mPFC). Whole-cell voltage clamp recordings were performed in vitro to quantitatively measure I(mAHP) and I(sAHP) and to examine their functional link to spike-frequency adaptation in the presence of agonists. CCh, 5-HT and NA all reduced the I(sAHP) and the spike adaptation, and, in some cells, replaced the I(sAHP) by the slow inward currents (I(sADP)) underlying the slow afterdepolarization (sADP).

Effects of cyclohexanonic long-chain fatty alcohol, tCFA15 on amino acids in diabetic rat brain: a preliminary study.

The aim of this study was to evaluate the effects of streptozotocin-induced type 1diabetes and a subchronic treatment with cyclohexanonic long-chain fatty alcohol, 3-(15-hydroxypentadecyl)-2,4,4-trimethyl-2-cyclohexen 1-one (tCFA15) on contents of amino acids including aspartate, glutamate, glutamine, GABA, glycine, taurine, alanine, serine, threonine, and arginine in the prefrontal cortex, hippocampus and striatum. Levels of glutamate, threonine, taurine, alanine, arginine, and the ratio of glutamate/glutamine were altered region-differently in the brain of diabetic rats. However, tCFA15 region-specifically antagonized the changes in taurine and arginine levels and the ratio of glutamate/glutamine.

Correlation between plasma levels of glutamate, alanine and serine with severity of depression.

The goal of this study was to evaluate the utility of using plasma levels of amino acids as an indicator of the severity of depression. The samples were collected from 23 depressed patients receiving antidepressant medication, and were compared to 31 healthy subjects. The plasma levels of amino acids were determined using HPLC with fluorometric detection.

Plasma levels of homovanillic acid, 5-hydroxyindoleacetic acid and cortisol, and serotonin turnover in depressed patients.

Plasma levels of ACTH, cortisol and monoamines were examined in 23 depressed patients and 31 healthy subjects. Patients showed increased plasma cortisol levels, but not plasma adrenocorticotropic hormone (ACTH) levels. The plasma levels of a dopamine metabolite, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), were significantly decreased in the patients.