Neural connection supporting endogenous 5-hydroxytryptamine influence on autonomic activity in medial prefrontal cortex

Evaluating proxies for motion sickness in rodent

Motions sickness (MS) occurs when the brain receives conflicting sensory signals from vestibular, visual and proprioceptive systems about a person's ongoing position and/or motion in relation to space. MS is typified by symptoms such as nausea and emesis and implicates complex physiological aspects of sensations and sensorimotor reflexes. Use of animal models has been integral to unraveling the physiological causality of MS. The commonly used rodents (rat and mouse), albeit lacking vomiting reflex, reliably display phenotypic behaviors of pica (eating of non-nutritive substance) and conditioned taste aversion (CTAver) or avoidance (CTAvoi) which utilize neural substrates with pathways that cause gastrointestinal malaise akin to nausea/emesis. As such, rodent pica and CTAver/CTAvoi have been widely used as proxies for nausea/emesis in studies dealing with neural mechanisms of nausea/emesis and MS, as well as for evaluating therapeutics. This review presents the rationale and experimental evidence that support the use of pica and CTAver/CTAvoi as indices for nausea and emesis. Key experimental steps and cautions required when using rodent MS models are also discussed. Finally, future directions are suggested for studying MS with rodent pica and CTAver/CTAvoi models.

Analysis of 5-hydroxytryptamine and its related indoles in cerebrospinal fluid of leukemic children by gas chromatography-mass spectrometry

Background

It is meaningful to quantify some neurotransmitters in cerebrospinal fluid (CSF) for pathology and clinical diagnosis. The objective of this study was to develop a rapid and reliable method for detecting 5-hydroxyindole ethanol (5-HTOL), 5-hydroxyindole acetic acid (5-HIAA), 5-hydroxytryptophan (5-HTP) and 5-hydroxytryptamine (5-HT) in CSF by gas chromatography-mass spectrometry (GC-MS), and explore the clinical significance of the levels of these neurotransmitters in CSF from acute lymphoblastic leukemia (ALL).

Methods

The levels of 5-HTOL, 5-HIAA, 5-HTP and 5-HT in CSF from children with ALL and a control (CON) group were examined by the proposed GC-MS method.

Results

The GC-MS method showed good sensitivity and accuracy. 5-HT and 5-HIAA contents in the ALL group were significantly lower than those in the CON group (p < 0.01), while there was no significant difference in 5-HTP and 5-HTOL contents between the two groups (p > 0.05).

Conclusions

This sensitive and reliable method could be used in studies focusing on clinical pathogenesis of ALL.