Depression continues to be a major global health problem. Although antidepressants are used for its treatment, efficacy is often inconsistent. Thus, the search for alternative therapeutic medicines for its treatment is still important. In this study, the antidepressant-like effect of Pseudospondias microcarpa extract (30-300 mg kg(-1), p.o.) was investigated in two predictive models of depressi...

1 In cats intracerebroventricular administration of 5, 10, 20 mug of peruvoside, a cardiac glycoside obtained from the plant, Thevetia neriifolia, and 10 and 20 mug of ouabain, produced marked neurotoxicity. This was dose-related. 2 Prior administration reserpine (2 mg/kg i.m., 500 mug i.c.v.) or tetrabenazine (25 mg/kg i.v., 50 mg/kg i.v. and 2 mg/,g i.c.v.) suppressed the neurotoxicity, but l...

Neuropathic pain can be considered as a form of chronic stress that may share common neuropathological mechanism between pain and stress-related depression and respond to similar treatment. Ferulic acid (FA) is a major active component of angelica sinensis and has been reported to exert antidepressant-like effects; however, it remains unknown whether FA ameliorate chronic constriction injury (C...

Serotonin is an important neurotransmitter that broadly participates in various biological processes. While serotonin deficiency has been associated with multiple pathological conditions such as depression, schizophrenia, Alzheimer's disease and Parkinson's disease, the serotonin-dependent mechanisms remain poorly understood. This study therefore aimed to identify novel biomarkers and metabolic...

Hyperglycemia has a profound effect on gastric motility. However, little is known about the site and mechanism that sense alteration in blood glucose level. The identification of glucose-sensing neurons in the nodose ganglia led us to hypothesize that hyperglycemia acts through vagal afferent pathways to inhibit gastric motility. With the use of a glucose-clamp rat model, we showed that glucose...

1 Experiments were performed on a variety of tissues from different species to establish whether or not the properties of p-chlorophenylalanine methyl ester (PCPA) included a 5-hydroxytryptamine (5HT)-like action which might explain the soporific action of PCPA in chicks. 2 PCPA, like 5-HT, contracted the rat fundal preparation (as did PCPA base), and in cats enhanced twitch tension of a lower ...

Using a computerized video-image analysis system, spontaneous locomotor activity was measured in dominant and subordinate individuals of Arctic charr (Salvelinus alpinus) and in individuals treated with inhibitors of serotonin (5-HT) synthesis and reuptake. Arctic charr were put together in pairs. After 1 week, subordinate individuals were found to have elevated brain levels of 5-hydroxyindolea...

Spontaneous synchronous rhythmic activities are a common feature of immature neuronal networks. Although the mechanisms underlying such activities have been studied extensively, whether they might be controlled by modulatory information remains questionable. Here, we investigated the role of descending serotonergic (5-HT) inputs from the medulla to the spinal cord in the maturation of rhythmic ...

The PET tracer [(11)C]5-hydroxytryptophan ([(11)C]5-HTP), which is converted to [(11)C]5-hydroxytryptamine ([(11)C]5-HT) by aromatic amino acid decarboxylase (AADC), is thought to measure 5-HT synthesis rates. But can we measure these synthesis rates by kinetic modeling of [(11)C]5-HTP in rat? Male rats were scanned with [(11)C]5-HTP (60 minutes) after different treatments. Scans included arter...

The plasma concentration of phenylalanine and tyrosine decreases in normal rats during the first few postnatal days; subsequently, the concentration of phenylalanine remains more or less constant, whereas that of tyrosine exhibits a high peak on day 13. The basal concentrations of the two amino acids were not altered by injections of thyroxine or cortisol, except in 13-day-old rats, when an inj...