Brain 5-HT receptor binding and its neural network related to behavioral inhibition system.

The tendency to avoid punishment, called behavioral inhibition system, is an essential aspect of motivational behavior. Behavioral inhibition system is related to negative affect, such as anxiety, depression and pain, but its neural basis has not yet been clarified. To clarify the association between individual variations in behavioral inhibition system and brain 5-HT receptor availability and specify which brain networks were involved in healthy male subjects, using [F]altanserin positron emission tomography and resting-state functional magnetic resonance imaging.

Resting-state functional connectivity relates to interindividual variations in positive memory.

Individual differences in positive memory recollection are of interest in mental health, as positive memories can help protect people against stress and depression. However, it is unclear how individual differences in positive memory recollection are reflected in brain activity in the resting state. Here, we investigate the resting-state functional connectivity (FC) associated with interindividual variations in positive memory by employing cluster-level inferences based on randomization/permutation region of interest (ROI)-to-ROI analyses.

Histamine H receptor density is negatively correlated with neural activity related to working memory in humans.

Background: The histamine H receptor is regarded as a drug target for cognitive impairments in psychiatric disorders. H receptors are expressed in neocortical areas, including the prefrontal cortex, the key region of cognitive functions such as working memory. However, the role of prefrontal H receptors in working memory has not yet been clarified.

Neuromolecular basis of faded perception associated with unreality experience.

Perceptual changes in shape, size, or color are observed in patients with derealization symptoms; however, the underlying neural and molecular mechanisms are not well understood. The current study explored the relationship between neural activity associated with altered colorfulness perception assessed by fMRI and striatal dopamine D receptor availability measured by [C]raclopride PET in healthy participants. Inside an fMRI scanner, participants performed the saturation adaptation task, where they rated how much vivid/faded visual objects looked like real/unreal ones using a visual analog scale.

Neural basis of negativity bias in the perception of ambiguous facial expression.

Negativity bias, which describes the tendency to interpret ambiguous stimuli or events as negative, is often observed in patients with depression and may prevent psychological well-being. Here, we used ambiguous facial stimuli, with negative (sad) and positive (happy) emotions simultaneously accessible, to examine neural activation during perceptual decision-making in healthy participants. The negativity bias was positively correlated with the activity of the bilateral pregenual anterior cingulate cortex (pgACC) when ambiguous faces were perceived as sad versus happy.

Norepinephrine Transporter in Major Depressive Disorder: A PET Study.

Objective: The norepinephrine transporter has been suggested to play a crucial role in major depressive disorder. However, norepinephrine transporter availability in major depressive disorder and its role with clinical symptoms are not known. The authors tested norepinephrine transporter availability in patients with major depressive disorder with the aim to identify any associations between test results and clinical symptoms.