Neural and sympathetic activity associated with exploration in decision-making: further evidence for involvement of insula.

We previously reported that sympathetic activity was associated with exploration in decision-making indexed by entropy, which is a concept in information theory and indexes randomness of choices or the degree of deviation from sticking to recent experiences of gains and losses, and that activation of the anterior insula mediated this association. The current study aims to replicate and to expand these findings in a situation where contingency between options and outcomes is manipulated. Sixteen participants performed a stochastic decision-making task in which we manipulated a condition with low uncertainty of gain/loss (contingent-reward condition) and a condition with high uncertainty of gain/loss (random-reward condition).

Genetic variations in the human cannabinoid receptor gene are associated with happiness.

Happiness has been viewed as a temporary emotional state (e.g., pleasure) and a relatively stable state of being happy (subjective happiness level).

Brain activation by music in patients in a vegetative or minimally conscious state following diffuse brain injury.

Objective: The aim of this study was to objectively evaluate the brain activity potential of patients with impaired consciousness in a chronic stage of diffuse brain injury (DBI) using functional MRI (fMRI) following music stimulation (MS).

Methods: Two patients in a minimally conscious state (MCS) and five patients in a vegetative state (VS) due to severe DBI were enrolled along with 21 healthy adults. This study examined the brain regions activated by music and assessed topographical differences of the MS-activated brain among healthy adults and these patients.

Brain-immune interaction accompanying odor-evoked autobiographic memory.

The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation.

Vagal nerve activity as a moderator of brain-immune relationships.

We investigated whether vagal tone, as assessed by heart rate variability (HRV), moderates the neural correlates of immune and physiological responses to acute stress. Participants with low and high baseline HRV underwent a reversal learning task as an acute stressor. Natural killer cells, norepinephrine, and adrenocorticotropic hormone in peripheral blood changed with acute stress in the high HRV group only.

Diagnostic accuracy of [¹⁸F]-fluoro-L-dihydroxyphenylalanine positron emission tomography scan for persistent congenital hyperinsulinism in Japan.

Objective: We aimed to elucidate the accuracy and limitations of [(18)F]-fluoro-L-dihydroxyphenylalanine ([(18) F]DOPA) positron emission tomography (PET) for Japanese patients with congenital hyperinsulinism. Although [(18)F]DOPA PET is reported to be useful for precisely localizing the focal form of congenital hyperinsulinism, previous reports are mostly from European and North American centres.

Patients: Seventeen Japanese infants with congenital hyperinsulinism.

Genetic variations in the serotonin transporter gene-linked polymorphic region influence attraction for a favorite person and the associated interactions between the central nervous and immune systems.

Limbic system activation that occurs when a person experiences several emotions is primarily represented by the amygdala output that influences autonomic brainstem nuclei that control autonomic nervous function, thus modulating the endocrine and immune systems. Amygdala activity is modulated by the serotonin transporter gene-linked polymorphic region (5HTTLPR); however, whether variations in 5HTTLPR influence central nervous and immune activities in response to positive stimuli remains unclear. Here, we found that seeing a favorite person induced significantly higher amygdala activity in individuals with the 5HTTLPR SS genotype than in others.

Polymorphism of the serotonin transporter gene modulates brain and physiological responses to acute stress in Japanese men.

A short (S) variant, compared to a long (L) variant, of the promoter region of the serotonin transporter gene-linked polymorphic region (5HTTLPR) has been related to emotional hyper-reactivity. We tested whether the 5HTTLPR could modulate acute stress responses in the brain and, the cardiovascular and neuroendocrine systems. Ten Japanese male participants carrying double copies of the S alleles and 10 Japanese males carrying S and L alleles conducted a mental arithmetic task, and their regional cerebral blood flow by (15)O positron emission tomography and cardiovascular and neuroendocrine parameters were measured.

Brain and autonomic association accompanying stochastic decision-making.

To examine the functional association between brain and autonomic activities accompanying decision-making, we simultaneously recorded regional cerebral blood flow using (15)O-water positron emission tomography and event-related brain potentials (ERPs) time-locked to feedback of reward and punishment, as well as cardiovascular parameters, during a stochastic decision-making task. We manipulated the uncertainty of outcomes in the task; specifically, we compared a condition with high predictability of reward/punishment (contingent-reward condition) and a condition with low predictability of reward/punishment (random-reward condition). The anterior cingulate cortex (ACC) was commonly activated in both conditions.

Regulation of natural killer cell redistribution by prefrontal cortex during stochastic learning.

Acute stress elicits redistribution of lymphocyte subsets, especially natural killer (NK) cells, probably for preparatory defense against potential invasion of antigens in fight-flight situations. We previously reported that regulation of lymphocyte redistribution is based on the evaluation of the controllability of a stressor (Kimura, K., Ohira, H.

Associations among positive mood, brain, and cardiovascular activities in an affectively positive situation.

It is hypothesized that experiencing positive emotions such as pleasure leads to a perception of the body being in a positive state. This study demonstrated associations among positive mood, brain, and cardiovascular activities by simultaneously recording these activities when positive emotions were evoked in participants watching films revolving around a love story. Heart rate variability analysis revealed increased parasympathetic nervous activity while watching the film.

Associations among central nervous, endocrine, and immune activities when positive emotions are elicited by looking at a favorite person.

Recent studies on psychoneuroimmunology have indicated that positive psychological events are related to immune functions; however, limited information is available regarding associations among the central nervous, endocrine, and immune systems when positive emotions are elicited. In the present study, we demonstrated associations among these systems by simultaneously recording brain, endocrine, and immune activities when positive emotions were evoked in participants as they watched films featuring their favorite persons. Interestingly, the activity of peripheral circulating natural killer cells and the peripheral dopamine level were elevated while participants experienced positive emotions, and these values were positively correlated.

Imaging brain and immune association accompanying cognitive appraisal of an acute stressor.

Acute stress elicits multiple responses in autonomic, endocrine, and immune systems. Cognitive appraisal is believed to be one important modulator of such stress responses. To investigate brain substrates of crosstalks between the homeostasis-maintaining systems accompanying appraisal of stressor controllability, we simultaneously recorded regional cerebral blood flow (rCBF) using 15O-water positron emission tomography, cardiovascular indices (heart rate (HR) and blood pressure (BP)), neuroendocrine indices (concentrations of epinephrine, norepinephrine, and adrenocorticotropic hormone (ACTH) in blood), and immune indices (proportions of subsets of lymphocytes (NK cells, helper T cells, cytotoxic T cells, and B cells) in blood), in 11 male subjects who performed a mental arithmetic task with either high controllability (HC) and low controllability (LC).

Association of neural and physiological responses during voluntary emotion suppression.

Recent neuroimaging studies have shown that several prefrontal regions play critical roles in inhibiting activation of limbic regions during voluntary emotion regulation. The present study aimed to confirm prior findings and to extend them by identifying the frontal neural circuitry associated with regulation of peripheral physiological responses during voluntary emotion suppression. Ten healthy female subjects were presented with affectively positive, neutral, and negative pictures in each of an Attending and Suppression task.