Increased blood serotonin concentrations are correlated with reduced tension/anxiety in healthy postpartum lactating women.

The serotonin (5-HT) system in the brain plays an important role in mood regulation. The postpartum period is considered a high-risk time for mood and anxiety disorders. We assessed changes in 5-HT levels in whole blood (as an indicator of brain 5-HT concentrations) and mood states before and after delivery in 28 healthy, lactating postpartum women.

Activation of the anterior prefrontal cortex and serotonergic system is associated with improvements in mood and EEG changes induced by Zen meditation practice in novices.

To gain insight into the neurophysiological mechanisms involved in Zen meditation, we evaluated the effects of focused attention (FA) on breathing movements in the lower abdomen (Tanden) in novices. We investigated hemodynamic changes in the prefrontal cortex (PFC), an attention-related brain region, using 24-channel near-infrared spectroscopy during a 20-minute session of FA on Tanden breathing in 15 healthy volunteers. We found that the level of oxygenated hemoglobin in the anterior PFC was significantly increased during FA on Tanden breathing, accompanied by a reduction in feelings of negative mood compared to before the meditation session.

Prolonged gum chewing evokes activation of the ventral part of prefrontal cortex and suppression of nociceptive responses: involvement of the serotonergic system.

We have proposed a concept that prolonged rhythmic gum chewing causes a suppressed nociceptive flexion reflex via the serotonergic (5-HT) descending inhibitory pathway. However, the mechanism of activation of the 5-HT system by gum chewing remains undetermined. Several human and animal studies have reported that a direct connection exists between the prefrontal cortex (PFC) and 5-HT neurons in the dorsal raphe nucleus; therefore, we hypothesized that activation of the PFC region might be responsible for augmented 5-HT activity.

Ventral prefrontal cortex and serotonergic system activation during pedaling exercise induces negative mood improvement and increased alpha band in EEG.

This study evaluates a possible involvement of the prefrontal cortex (PFC) and serotonergic (5-HT) system in psychiatric and electroencephalography (EEG) changes during and after pedaling exercise (PE). The subjects performed PE for 15 min using a cycle ergometer. PE rate was kept at 60 rpm, and the work load (93+/-5.

Decreased blood serotonin in the premenstrual phase enhances negative mood in healthy women.

The purpose of this study was to evaluate mechanisms underlying the action of selective serotonin reuptake inhibitors on the improvement of negative mood symptoms in premenstrual syndrome. We assessed relationships between serotonin (5-HT) levels in the brain (estimated from 5-HT concentrations in whole blood) and negative mood states during the premenstrual phase in 13 healthy women. Mood states were evaluated using the Profile of Mood States questionnaire.