Identification of the neural correlates of cyclothymic temperament using a working memory task in fMRI.

Background: Recently, we reported a significantly negative association of cyclothymic temperament scores with activations of the left lingual gyrus during esthetic judgments of paintings, suggesting that cyclothymic temperament may be associated with the left lingual gyrus. In view of potential associations of cyclothymic temperament, bipolar disorder and dementia, this study examined the relationship of temperament to lingual gyrus activity using a working memory task as a new context.

Methods: N-back tasks (0-, 1-, 2- and 3-back tasks) were performed on 34 healthy subjects using functional MRI.

Identification of the neural correlates of cyclothymic temperament using an esthetic judgment for paintings task in fMRI.

Background: There is a well-known association between artistic creativity and cyclothymic temperament but the neural correlates of cyclothymic temperament have not yet been fully identified. Recently, we showed that the left lingual gyrus and bilateral cuneus may be associated with esthetic judgment of representational paintings, we therefore sought to investigate brain activity during esthetic judgment of paintings in relation to measures of cyclothymic temperament.

Methods: Regions of interest (ROI) were set at the left lingual gyrus and bilateral cuneus using automated anatomical labeling, and percent signal changes of the ROIs were measured by marsbar toolbox.

Difference in brain activations during appreciating paintings and photographic analogs.

Several studies have investigated neural correlates of aesthetic appreciation for paintings but to date the findings have been heterogeneous. This heterogeneity may be attributed to previous studies' measurement of aesthetic appreciation of not only the beauty of paintings but also the beauty of motifs of the paintings. In order to better elucidate the beauty of paintings, it seems necessary to compare aesthetic appreciation of paintings and photographic analogs which included corresponding real images.

Association between affective temperaments and regional gray matter volume in healthy subjects.

Background: Affective temperaments such as cyclothymic and hyperthymic temperaments have been regarded as potential antecedents of bipolar disorder but the neural substrates underlying these temperaments have not been identified. The aim of this study is to determine whether these temperaments are associated with specific neural substrates in regional brain morphology in healthy subjects.

Methods: We conducted a cross-sectional neuroimaging study of 60 healthy subjects (30 males and 30 females) with affective temperaments.

Hyperthymic temperament and rapid reaction time in brightness preference.

Background: It is well-known that Type A behavior pattern is characterized by hard-driving, competitive behavior and time urgency. Also, people with hyperthymic temperament are known to have high energy levels and are full of plans. It is therefore hypothesized that hyperthymic temperament is associated with rapid processing and fast reaction time in making decisions.

Hyperthymic temperament and brightness preference in healthy subjects: further evidence for involvement of left inferior orbitofrontal cortex in hyperthymic temperament.

Background: Hyperthymic temperament has been generally accepted as one of premorbid temperament of bipolar disorders. Although several studies indicate that subjects with hyperthymic temperament receive more illuminance, our recent study suggests that the threshold of brightness and darkness judgment is not different between more and less hyperthymic subjects, and that hyperthymic temperament may be associated with left inferior orbitofrontal cortex, which has been reported to be associated with bipolar disorder. Therefore, at the next stage, it can be hypothesized that hyperthymic subjects may prefer brightness (i.

Hyperthymic temperament and brightness judgment in healthy subjects: involvement of left inferior orbitofrontal cortex.

Background: Hyperthymic temperament has been generally accepted as one of premorbid temperament of bipolar disorders. Since recent several studies indicate an association between illuminance and hyperthymic temperament, it can be hypothesized that more hyperthymic temperament subjects have a different threshold of brightness or darkness perception in comparison with less hyperthymic temperament subjects.

Methods: We compared the threshold of brightness and darkness judgment between more and less hyperthymic subjects, and by simultaneously using fMRI we compared activations of whole brain between these subjects by two sample t-test.

Salivary alpha-amylase and cortisol responsiveness following electrical stimulation stress in major depressive disorder patients.

Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis by chronic stress. In comparison, psychosocial stress-induced activation of salivary α-amylase (sAA) functions as a marker of sympathoadrenal medullary system (SAM) activity. However, in contrast to salivary cortisol, sAA has been less extensively studied in MDD patients.

Elevated salivary α-amylase and cortisol levels in unremitted and remitted depressed patients.

Abstract Objective. Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis via chronic stress. Psychosocial stress-induced activation of salivary α-amylase (sAA) represents sympathoadrenal medullary system (SAM) activity, and sAA has become an emerging biomarker for sympathetic nervous system activity.

Social support and enhanced suppression of adrenocorticotropic hormone and cortisol responses to hypothalamic-pituitary-adrenal function and thyrotropin-releasing hormone tests in patients with major depressive disorder.

The results of the thyrotropin-releasing hormone (TRH) stimulation test and the combined dexamethasone/corticotropin-releasing hormone (DEX/CRH) test are believed to correlate with social support status in patients with major depressive disorder. We studied 41 consecutive patients hospitalized for major depressive disorder and tested their responses to DEX/CRH and TRH on hospital days 4-7. DeltaMAX TSH and DeltaMAX cortisol were measured.

Administration of antisense DNA for ghrelin causes an antidepressant and anxiolytic response in rats.

Rationale: Ghrelin is a peptide of 28 amino acids found in mammals that increases the release of growth hormone, food intake, and body weight.

Objectives: We investigated the relationship between ghrelin and the states of anxiety and depression by giving rats either antisense DNA for ghrelin, scrambled DNA or vehicle into the lateral ventricle of rats.

Results: In forced swimming tests, rats that received antisense DNA decreased the length of time that they were immobile in the water.

Anxiolytic suppression of repetitive transcranial magnetic stimulation-induced anxiety in the rats.

Repetitive transcranial magnetic stimulation (rTMS) is effective for treatment of several psychiatric disorders such as depression and anxiety disorder. However, some reports suggest that rTMS induced anxiety in normal volunteers. Consistent with this observation, we have reported that chronic rTMS induces anxiety in normal rats which was suppressed by chronic treatment, but not acute paroxetine treatment.

Anxiolytic effect of hepatocyte growth factor infused into rat brain.

Background: Hepatocyte growth factor (HGF) has the capacity to selectively direct thalamocortical projections into an intermediate target, the pallidum, and eventually to their final cortical destination. HGF may have a role in the mediation of anxiety. Very little is known about other central behavioral effects of HGF.

Anxiogenic-like effect of corticotropin-releasing factor receptor 2 antisense oligonucleotides infused into rat brain.

Corticotropin-releasing factor (CRF) is widely distributed in the brain and coordinates behavioural responses to stress. Its receptor subtypes, CRF-R1 and CRF-R2, are expressed in the brain. For this study, we tested the effect of a continuous infusion of CRF-R2 antisense oligonucleotides into the lateral ventricle on anxiety-related behaviours in rats.

Spatial memory impairment in OLETF rats without cholecystokinin - a receptor.

Cholecystokinin (CCK) is one of the most abundant neurotransmitter peptides in the brain. As Otsuka Long-Evans Tokushima Fatty (OLETF) rats lack CCK-A receptor because of a genetic abnormality, we examined whether learning and memory were impaired in these animals using both Morris water maze (MWM) and step-through type passive avoidance (PA) learning test. In the MWM test, memory impairment was observed in OLETF rats.