Contribution of the brain-derived neurotrophic factor and neurometabolites to the motor performance.

Individual motor performance ability is affected by various factors. Although the key factor has not yet completely been elucidated, the brain-derived neurotrophic factor (BDNF) genotype as well as neurometabolites may become contibuting factors depending on the learning stage. We investigated the effects of the Met allele of the BDNF gene and those of the neurometabolites on visuomotor learning. In total, 43 healthy participants performed a visuomotor learning task consisting of 10 blocks using the right index finger (Val66Val, n = 15; Val66Met, n = 15; and Met66Met, n = 13). Glutamate plus glutamine (Glx) concentrations in the primary motor cortex, primary somatosensory cortex (S1), and cerebellum were evaluated using 3-T magnetic resonance spectroscopy in 19 participants who participated in the visuomotor learning task. For the learning stage, the task error (i.e., learning ability) was significantly smaller in the Met66Met group compared with that observed in the remaining groups, irrespective of the learning stage (all p values < 0.003). A significant difference was observed between the Val66Val and Met66Met groups in the learning slope (i.e., learning speed) in the early learning stage (p = 0.048) but not in the late learning stage (all p values> 0.54). Moreover, positive correlations were detected between the learning slope and Glx concentrations in S1 only in the early learning stage (r = 0.579, p = 0.009). The BDNF genotype and Glx concentrations in S1 partially contribute to interindividual variability on learning speed in the early learning stage.

Rikkunshi-to attenuates adverse gastrointestinal symptoms induced by fluvoxamine.

BACKGROUND: Upper gastrointestinal (GI) symptoms such as nausea and vomiting are common adverse events associated with selective serotonin reuptake inhibitors (SSRIs), and may result in discontinuation of drug therapy in patients with depressive disorder. Rikkunshi-to (formulation TJ-43), a traditional herbal medicine, has been reported to improve upper GI symptoms and comorbid depressive symptoms in patients with functional dyspepsia. The aim of the present study was to determine if TJ-43 reduces GI symptoms and potentiates an antidepressant effect in a randomized controlled study of depressed patients treated with fluvoxamine (FLV). METHODS: Fifty patients with depressive disorder (19-78 years, mean age 40.2 years) were treated with FLV (n = 25) or FLV in combination with TJ-43 (FLV+TJ-43) (n = 25) for eight weeks. The following parameters of the two groups were compared: The number of patients who complained of adverse events and their symptoms; GI symptoms quality of life (QOL) score, assessed by the Gastrointestinal Symptom Rating Scale (GSRS), Japanese edition, before and two weeks after beginning treatment; and depressive symptoms assessed by the Self-Rating Depression Scale (SDS), before and 2, 4, and 8 weeks after beginning treatment. RESULTS: The number of patients who complained of adverse events in the FLV+TJ-43 group (n = 6) was significantly lower than the number complaining in the FLV group (n = 13) (P < 0.05). The number of patients who complained of nausea was also lower in the FLV+TJ-43 group (n = 3) than in the FLV group (n = 9) (P < 0.05). By two weeks after treatment, GSRS scores had improved in the FLV+TJ-43 group, but not in the FLV group. SDS scores were not different between the two groups at any of the assessment points. CONCLUSION: This study suggests that Rikkunshi-to reduces FLV-induced adverse events, especially nausea, and improves QOL related to GI symptoms without affecting the antidepressant effect of FLV.