Acute hyperglycemia is related to gastrointestinal symptoms in motion sickness: an experimental study. Physiol Behav. 2012;105:394-401. [PMID: 21907224 DOI: 10.1016/j.physbeh.2011.08.024]

Circuits and Biomarkers of the Central Nervous System Relating to Astronaut Performance: Summary Report for a NASA-Sponsored Technical Interchange Meeting

Biomarkers, ranging from molecules to behavior, can be used to identify thresholds beyond which performance of mission tasks may be compromised and could potentially trigger the activation of countermeasures. Identification of homologous brain regions and/or neural circuits related to operational performance may allow for translational studies between species. Three discussion groups were directed to use operationally relevant performance tasks as a driver when identifying biomarkers and brain regions or circuits for selected constructs. Here we summarize small-group discussions in tables of circuits and biomarkers categorized by (a) sensorimotor, (b) behavioral medicine and (c) integrated approaches (e.g., physiological responses). In total, hundreds of biomarkers have been identified and are summarized herein by the respective group leads. We hope the meeting proceedings become a rich resource for NASA's Human Research Program (HRP) and the community of researchers.

Biochemical analysis reveals the systematic response of motion sickness mice to ginger (Zingiber officinale) extract's amelioration effect

ETHNOPHARMACOLOGICAL RELEVANCE

As a common medicinal and edible plant, Zingiber officinale Roscoe (ginger) is often used for the prevention of motion sickness. However, the mechanism of its anti-motion sickness remains to be elucidated.

AIM OF THE STUDY

To explore novel treatment for motion sickness with less side effects, anti-motion sickness effect of ginger (Zingiber officinale) extract (GE) and the possible molecular mechanisms were investigated.

MATERIALS AND METHODS

The anti-motion sickness effect of ginger was evaluated through mice animal experimental models. Components of ginger that might contribute to the anti-motion sickness effect were analyzed by LC-MS/MS. Subsequently, biochemical analysis integrated with serum metabolomic profiling were performed to reveal the systematic response of motion sickness mice to ginger extract's amelioration effect.

RESULTS

Exhaustive swimming time of mice in the GE group reached 8.9 min, which was 52.2% longer than that in the model group. Motion sickness index scores and time taken traversing balance beam of mice in the GE group were decreased by 53.2% and 38.5%, respectively. LC-MS/MS analysis suggested that various active ingredients in GE, such as gingerol, ginger oil and terpenoids, might contribute to its appealing anti-motion sickness activity. Biochemical analysis revealed that GE can relieve motion sickness through reducing histamine and acetylcholine release in vestibular system, regulating fatty acid oxidation, sugar metabolism and bile acid metabolism in mice.

CONCLUSION

Gavage of mice with GE can effectively relieve the symptoms of autonomic nervous system dysfunction, improve the balance and coordination ability and ameliorate the ability to complete complex work after rotation stimulation. GE has attractive potential for development and utilization as novel anti-motion sickness food or drugs.

Integrated metabolomics and network pharmacology approach to exploring the potential mechanism of tianxiang capsule for treating motion sickness

ETHNOPHARMACOLOGICAL RELEVANCE

Motion sickness is a multi-system syndrome caused by abnormal spatial environmental sensory conflicts. Tianxiang Capsule (TXC) is a traditional Chinese medicine (TCM) formula for the prevention and treatment of motion sickness for years. However, the main active components of TXC and mechanism of its therapeutic effects on motion sickness are still unclear.

AIM OF THE STUDY

The purpose of this work is to investigate the mechanism of TXC in preventing motion sickness based on serum metabolomics and network pharmacology. On the basis of the clear validation of the anti-motion sickness effect of TXC, we used the strategy of combined GC-MS metabolomics and network pharmacology to screen 60 differential metabolites regulated by TXC.

MATERIALS AND METHODS

The rat models of motion sickness were stimulated by biaxial rotational acceleration, spontaneous activity was used to evaluate the efficacy of TXC on motion sickness. Serum metabolomics-based analysis was conducted to screen the differential metabolites related to motion sickness. Then, network pharmacology analysis was used to integrate the information of differential metabolites with target proteins and chemical components, and the "components-target protein-metabolite related protein-metabolite" network was constructed to explore the mechanism of the protective effect of TXC against motion sickness.

RESULTS

The results of network integration analysis showed that the 50 TXC potential active ingredients mediated the differential expression of 49 metabolic biomarkers by targeting 25 target protein and regulated arachidonic acid metabolism, calcium signaling pathways, etc. In addition, we found that TXC can promote the secretion of insulin mediated by arachidonic acid pathway metabolites, regulate the levels of adrenaline and leptin, maintain blood glucose balance, and achieve the therapeutic effect of motion sickness.

CONCLUSIONS

Our results indicated that the arachidonic acid metabolic pathway and related targets are the key ways for TXC to exert its efficacy, and its target protein and anti-motion sickness mechanism deserve further study. Our work proved that the integrated strategy of metabolomics and network pharmacology can well explain the "multi-component - multi-target" mechanism of complex TCM in vivo, which is a practical approach for the study of TCM formula.

Pyruvate accumulation may contribute to acceleration-induced impairment of physical and cognitive abilities: an experimental study

Background: Fatigue can be induced after acceleration exposure, however its mechanism is still unclear. The aim of the present study was to examine whether metabolites’ changes can decrease cognitive and physical function after acceleration. Methods: Graybiel scale and Fatigue Self-rating scale were used to assess the seasickness and fatigue degrees of 87 male seafarers respectively after sailing. To test the effect of pyruvate on cognitive and physical functions, five different doses of pyruvate were administrated into rats. Insulin can reduce the accumulation of pyruvate. To observe the insulin effect on pyruvate, cognitive and physical functions after acceleration, insulin administration or treatment of promoting insulin secretion was used. Physical and cognitive functions were assessed using open field test (OFT), morris water maze (MWM) and loaded swimming test (LST) in animals. Results: Physical and cognitive abilities were decreased obviously, and serum pyruvate increased mostly in human and rats after acceleration. Compared with vehicle group, physical and cognitive abilities were significantly decreased after pyruvate administration. Besides, we found a significant decline in adenosine triphosphate (ATP) concentration and pyruvate dehydrogenase (PDH) activity in the hippocampus, prefrontal cortex, liver, and muscle of rats treated with acceleration or pyruvate injection, while insulin administration or treatment of promoting insulin secretion markedly alleviated this decline and the impairment of physical and cognitive abilities, compared with the control group. Conclusion: Our results indicate that pyruvate has a negative effect on physical and cognitive abilities after acceleration. Insulin can inhibit pyruvate accumulation and cognitive and physical function after acceleration exposure.

Prior transfusion of umbilical cord mesenchymal stem cells can effectively alleviate symptoms of motion sickness in mice through interleukin 10 secretion

BACKGROUND

Motion sickness (MS) is a disease that occurs during unbalanced movement, characterized by gastrointestinal symptoms and autonomic nervous system activation. Current clinical treatments for MS are limited. Recent evidence indicates that the levels of pro-inflammatory cytokines increase during MS and are associated with an inner ear immune imbalance. In the present study, mesenchymal stem cells (MSCs) have been shown to exert strong immuno-suppressive effects.

AIM

To explore whether umbilical cord-derived mesenchymal stem cells (UC-MSCs) can prevent the occurrence of MS, and the underlying mechanism regulated by MSCs in a mouse model of MS.

METHODS

A total of 144 (equal numbers of males and females) 5wkold BALB/c mice were randomly divided into five groups: Normal group (n = 16), MS group (n = 32), MSCs group (n = 32), MS + MSCs group (n = 32), and MS + AS101/MSCs group (n = 32). The MSCs group (n = 32), MS + MSCs group (n = 32), and MS + AS101/MSCs group (n = 32) were preventively transplanted with UC-MSCs or AS101-treated UC-MSCs (1 × 10⁶ cells/mouse). Mice in the MS (n = 32), MS + MSCs, and MS + AS101/MSCs groups were subjected to rotation on a centrifuge for 10 min at 8 × g/min for MS model establishment on days 3, 5, 8, and 10 after UC-MSCs injection. The Morris water maze (MWM) test was used to observe the symptom of dizziness. Enzyme-linked immunosorbent assay (ELISA) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect the levels of inflammatory cytokines in mice peripheral blood and the petrous part of the temporal bone samples. Western blot analysis was performed to analyze the JAK2/STAT3 signaling pathway in the cochlear tissues. Histological examination was performed by hematoxylin and eosin (HE) staining for conventional morphological evaluation in the petrous part of temporal bone samples.

RESULTS

The MWM test demonstrated that UC-MSCs improved the symptoms of MS. The MS + MSCs group was faster than the MS group on days 3 and 5 (P = 0.036 and P = 0.002, respectively). ELISA and RT-qPCR showed that the serum and mRNA levels of interleukin-10 (IL-10) in the cochlear tissues were increased after transplantation with UC-MSCs (MS + MSCs group vs MS group at 3 and 5 d, P = 0.002 and ^cP < 0.001, respectively). RT-qPCR results confirmed a significant increase in IL-10 levels at four time points (MS + MSCs group vs MS group, P = 0.009, P = 0.009, P = 0.048, and P = 0.049, respectively). This suggested that UC-MSCs reduced the sensitivity of the vestibular microenvironment by secreting IL-10. Moreover, Western blot analysis showed that the MSCs activated the JAK2/STAT3 signaling pathway in the cochlear tissues. The levels of IL-10, IL-10RA, JAK2, STAT3, and phosphorylated JAK2 and STAT3 in the MS + MSCs group were increased compared to those of the MS group (P < 0.05). The morphological changes in the four groups showed no significant differences. The role of IL-10 secretion on the ability of UC-MSCs to successfully improve the symptoms of MS was confirmed by the diminished therapeutic effects associated with treatment with the IL-10 inhibitor ammonium trichloro (dioxoethylene-o,o′) tellurate (AS101).

CONCLUSION

Prophylactic transplantation of UC-MSCs can alleviate the clinical symptoms of MS in mice, particularly at 3-5 d after preventive transplantation. The mechanism for UC-MSCs to reduce the sensitivity of vestibular cortex imbalance may be the secretion of IL-10. The next step is to demonstrate the possibility of curing MS in the vestibular environment by intermittent transplantation of MSCs. Above all, MSCs are expected to become a new method for the clinical prevention and treatment of MS.

Motion sickness diagnostic criteria: Consensus document of the classification committee of the Bárány society

We present diagnostic criteria for motion sickness, visually induced motion sickness (VIMS), motion sickness disorder (MSD), and VIMS disorder (VIMSD) to be included in the International Classification of Vestibular Disorders. Motion sickness and VIMS are normal physiological responses that can be elicited in almost all people, but susceptibility and severity can be high enough for the response to be considered a disorder in some cases. This report provides guidelines for evaluating signs and symptoms caused by physical motion or visual motion and for diagnosing an individual as having a response that is severe enough to constitute a disorder.

   The diagnostic criteria for motion sickness and VIMS include adverse reactions elicited during exposure to physical motion or visual motion leading to observable signs or symptoms of greater than minimal severity in the following domains: nausea and/or gastrointestinal disturbance, thermoregulatory disruption, alterations in arousal, dizziness and/or vertigo, headache and/or ocular strain. These signs and/or symptoms occur during the motion exposure, build as the exposure is prolonged, and eventually stop after the motion ends. Motion sickness disorder and VIMSD are diagnosed when recurrent episodes of motion sickness or VIMS are reliably triggered by the same or similar stimuli, severity does not significantly decrease after repeated exposure, and signs/symptoms lead to activity modification, avoidance behavior, or aversive emotional responses.

   Motion sickness/MSD and VIMS/VIMSD can occur separately or together. Severity of symptoms in reaction to physical motion or visual motion stimuli varies widely and can change within an individual due to aging, adaptation, and comorbid disorders. We discuss the main methods for measuring motion sickness symptoms, the situations conducive to motion sickness and VIMS, and the individual traits associated with increased susceptibility. These additional considerations will improve diagnosis by fostering accurate measurement and understanding of the situational and personal factors associated with MSD and VIMSD.

Acupuncture relieves motion sickness via the IRβ-ERK1/2-dependent insulin receptor signalling pathway

OBJECTIVE

Acupuncture has been widely used for the treatment of motion sickness (MS), but the underlying mechanisms are unclear. The aim of this research was to study the mechanism of acupuncture in the treatment of MS.

METHODS

To observe the effects of acupuncture in the treatment of MS, 80 rats were randomised into five groups that were subjected to acceleration and either remained untreated (CTRL), or received restraint (REST), scopolamine (SCOP) or acupuncture at SP4 (sham) or PC6+ST36 (verum) acupuncture points. To study the mechanism underlying the effects of acupuncture in the treatment of MS, 48 rats were randomised into three groups: acupuncture+extracellular regulated protein kinases (ERK) 1/2 inhibitor (ERKinh), acupuncture+insulin receptor (IR) antagonist (IRant), and acupuncture+vehicle (VEH). After acceleration, the MS index (MSI) and spontaneous activity (SA) of the rats were recorded. Serum stress hormones, Fos-positive cells, c-fos mRNA in the vestibular nucleus, and IRβ-, p-IRβ-, ERK1/2- and p-ERK1/2-positive cells in the dorsal motor nucleus of the vagus nerve (DMV) were detected.

RESULTS

After acceleration, MS symptoms in the PC6+ST36 and SCOP groups were reduced compared with the CTRL, REST, and SP4 groups. The number of p-IRβ- and p-ERK1/2-positive cells and insulin levels were higher in the PC6+ST36 group than in the CTRL, REST, and SP4 groups. After ERK1/2 inhibitor and IR antagonist treatment, MS symptoms in the VEH group were lower than in the ERKinh and IRant groups.

CONCLUSIONS

Our study demonstrates that acupuncture significantly alleviates MS through the IRβ-ERK1/2-dependent insulin receptor signalling pathway in the DMV.

Sex and Age Differences in Motion Sickness in Rats: The Correlation with Blood Hormone Responses and Neuronal Activation in the Vestibular and Autonomic Nuclei

Many studies have demonstrated sex and age differences in motion sickness, but the underlying physiological basis is still in controversy. In the present study, we tried to investigate the potential correlates of endocrine and/or neuronal activity with sex and age differences in rats with motion sickness. LiCl-induced nausea symptom was evaluated by conditioned gaping. Motion sickness was assessed by measurement of autonomic responses (i.e., conditioned gaping and defecation responses), motor impairments (i.e., hypoactivity and balance disturbance) after Ferris wheel-like rotation, and blood hormone levels and central Fos protein expression was also observed. We found that rotation-induced conditioned gaping, defecation responses and motor disorders were significantly attenuated in middle-aged animals (13- and 14-month-age) compared with adolescents (1- and 2-month-age) and young-adults (4- and/or 5-month-age). LiCl-induced conditioned gapings were also decreased with age, but was less pronounced than rotation-induced ones. Females showed greater responses in defecation and spontaneous locomotor activity during adolescents and/or young-adult period. Blood adrenocorticotropic hormone and corticosterone significantly increased in 4-month-old males after rotation compared with static controls. No significant effect of rotation was observed in norepinephrine, epinephrine, β-endorphin and arginine-vasopressin levels. The middle-aged animals (13-month-age) also had higher number of rotation-induced Fos-labeled neurons in the spinal vestibular nucleus, the parabrachial nucleus (PBN), the central and medial nucleus of amygdala (CeA and MeA) compared with adolescents (1-month-age) and young-adults (4-month-age) and in the nucleus of solitary tract (NTS) compared with adolescents (1-month-age). Sex difference in rotation-induced Fos-labeling was observed in the PBN, the NTS, the locus ceruleus and the paraventricular hypothalamus nucleus at 4 and/or 13 months of age. These results suggested that the sex and age differences in motion sickness may not correlate with stress hormone responses and habituation. The age-dependent decline in motion sickness susceptibility might be mainly attributed to the neuronal activity changes in vestibulo-autonomic pathways contributing to homeostasis regulation during motion sickness.

The Combination of Scopolamine and Psychostimulants for the Prevention of Severe Motion Sickness

BACKGROUND AND AIMS

Severe motion sickness is a huge obstacle for people conducting precise aviation, marine or emergency service tasks. The combination of scopolamine and d-amphetamine is most effective in preventing severe motion sickness. However, this combination is not included in any present pharmacopoeia due to the abuse liability of d-amphetamine. We wanted to find a combination to replace it for the treatment of severe motion sickness.

METHODS AND RESULTS

We compared the efficacy of scopolamine, diphenhydramine, and granisetron (representing three classes of drugs) with different doses, and found that scopolamine was the most effective one. We also found scopolamine inhibited central nervous system at therapeutic doses and caused anxiety. Then, we combined it with different doses of psychostimulants (d-amphetamine, modafinil, caffeine) to find the best combination for motion sickness. The efficacy of scopolamine with modafinil (1 + 10 mg/kg) was equivalent to that of scopolamine with d-amphetamine (1 + 1 mg/kg); This combination also excited central nervous system and abolished the anxiety caused by scopolamine.

CONCLUSIONS

The optimal dose ratio of scopolamine and modafinil is 1:10. This combination is beneficial for motion sickness and can abolish the side effects of scopolamine. So, it might be a good replacement of scopolamine and d-amphetamine for severe motion sickness.

Motion Sickness: Current Knowledge and Recent Advance

Motion sickness (MS) is a common physiological response to real or virtual motion. Numerous studies have investigated the neurobiological mechanism and the control measures of MS. This review summarizes the current knowledge about pathogenesis and pathophysiology, prediction, evaluation, and countermeasures of MS. The sensory conflict hypothesis is the most widely accepted theory for MS. Both the hippocampus and vestibular cortex might play a role in forming internal model. The pathophysiology focuses on the visceral afference, thermoregulation and MS-related neuroendocrine. Single-nucleotide polymorphisms (SNPs) in some genes and epigenetic modulation might contribute to MS susceptibility and habituation. Questionnaires, heart rate variability (HRV) and electrogastrogram (EGG) are useful for diagnosing and evaluating MS. We also list MS medications to guide clinical practice. Repeated real motion exposure and combined visual-vestibular interaction training accelerate the progress of habituation. Behavioral and dietary countermeasures, as well as physiotherapy, are also effective in alleviating MS symptoms.

Genetic variants associated with motion sickness point to roles for inner ear development, neurological processes and glucose homeostasis

Roughly one in three individuals is highly susceptible to motion sickness and yet the underlying causes of this condition are not well understood. Despite high heritability, no associated genetic factors have been discovered. Here, we conducted the first genome-wide association study on motion sickness in 80 494 individuals from the 23andMe database who were surveyed about car sickness. Thirty-five single-nucleotide polymorphisms (SNPs) were associated with motion sickness at a genome-wide-significant level (P < 5 × 10(-8)). Many of these SNPs are near genes involved in balance, and eye, ear and cranial development (e.g. PVRL3, TSHZ1, MUTED, HOXB3, HOXD3). Other SNPs may affect motion sickness through nearby genes with roles in the nervous system, glucose homeostasis or hypoxia. We show that several of these SNPs display sex-specific effects, with up to three times stronger effects in women. We searched for comorbid phenotypes with motion sickness, confirming associations with known comorbidities including migraines, postoperative nausea and vomiting (PONV), vertigo and morning sickness and observing new associations with altitude sickness and many gastrointestinal conditions. We also show that two of these related phenotypes (PONV and migraines) share underlying genetic factors with motion sickness. These results point to the importance of the nervous system in motion sickness and suggest a role for glucose levels in motion-induced nausea and vomiting, a finding that may provide insight into other nausea-related phenotypes like PONV. They also highlight personal characteristics (e.g. being a poor sleeper) that correlate with motion sickness, findings that could help identify risk factors or treatments.

Differential Gene Expression Profile in the Rat Caudal Vestibular Nucleus is Associated with Individual Differences in Motion Sickness Susceptibility

OBJECTIVE

To identify differentially expressed genes associated with motion sickness (MS) susceptibility in the rat caudal vestibular nucleus.

METHODS

We identified MS susceptible (MSS) and insusceptible (inMSS) rats by quantifying rotation-induced MS symptoms: defecation and spontaneous locomotion activity. Microarray analysis was used to screen differentially expressed genes in the caudal vestibular nucleus (CVN) after rotation. Plasma stress hormones were identified by radioimmunoassay. Candidate genes were selected by bioinformatics analysis and the microarray results were verified by real-time quantitative-PCR (RT-qPCR) methods. By using Elvax implantation, receptor antagonists or recombinant adenovirus targeting the candidate genes were applied to the CVN to evaluate their contribution to MS susceptibility variability. Validity of gene expression manipulation was verified by RT-qPCR and western blot analysis.

RESULTS

A total of 304 transcripts were differentially expressed in the MSS group compared with the inMSS group. RT-qPCR analysis verified the expression pattern of candidate genes, including nicotinic cholinergic receptor (nAchR) α3 subunit, 5-hydroxytryptamine receptor 4 (5-HT4R), tachykinin neurokinin-1 (NK1R), γ-aminobutyric acid A receptor (GABAAR) α6 subunit, olfactory receptor 81 (Olr81) and homology 2 domain-containing transforming protein 1 (Shc1). In MSS animals, the nAchR antagonist mecamylamine significantly alleviated rotation-induced MS symptoms and the plasma β-endorphin response. The NK1R antagonist CP99994 and Olr81 knock-down were effective for the defecation response, while the 5-HT4R antagonist RS39604 and Shc1 over-expression showed no therapeutic effect. In inMSS animals, rotation-induced changes in spontaneous locomotion activity and the plasma β-endorphin level occurred in the presence of the GABAAR antagonist gabazine.

CONCLUSION

Our findings suggested that the variability of the CVN gene expression profile after motion stimulation might be a putative molecular basis for individual differences in MS susceptibility and provide information for the development of new therapeutic strategies for MSS individuals.

The role of cannabinoids in regulation of nausea and vomiting, and visceral pain

Marijuana derived from the plant Cannabis sativa has been used for the treatment of many gastrointestinal (GI) disorders, including anorexia, emesis, abdominal pain, diarrhea, and others. However, its psychotropic side effects have often limited its use. Several cannabinoid receptors, which include the cannabinoid receptor 1 (CB1), CB2, and possibly GPR55, have been identified throughout the GI tract. These receptors may play a role in the regulation of food intake, nausea and emesis, gastric secretion and gastroprotection, GI motility, ion transport, visceral sensation, intestinal inflammation, and cell proliferation in the gut. However, the regulation of nausea and vomiting by cannabinoids and the endocannabinoid system has shed new knowledge in this field. Thus far, despite evidence of visceral sensitivity inhibition in animal models, data in irritable bowel syndrome (IBS) patients is scarce and not supportive. Furthermore, many compounds that either act directly at the receptor or increase (or reduce) ligand availability have the potential to affect other brain functions and cause side effects. Novel drug targets such as FAAH and monoacylglycerol lipase (MAGL) inhibitors appear to be promising in animal models, but more studies are necessary to prove their efficiency. The promise of emerging drugs that are more selective and peripherally acting suggest that, in the near future, cannabinoids will play a major role in managing an array of GI diseases.

Dexamethasone alleviates motion sickness in rats in part by enhancing the endocannabinoid system

Low-dose dexamethasone has been widely used for the prevention of nausea and vomiting after chemotherapy and surgical procedures and to treat motion sickness due to its minimal adverse effects, but the mechanisms underlying its anti-motion sickness effects are poorly understood. Previous studies have demonstrated that the endocannabinoid system is suppressed by motion sickness but stimulated by dexamethasone. The aim of the present study was to determine whether dexamethasone has an anti-motion sickness effect in rats and to elucidate the mechanism of this action. We used HPLC-MS/MS to measure the plasma concentrations of anandamide and 2-arachidonoylglycerol+1-arachidonoylglycerol, and we employed real-time quantitative PCR (qRT-PCR) and/or Western blot analysis to assay the expression of N-acylphosphatidyl-ethanolamine hydrolyzing phospholipase D, sn-1-selective diacylglycerol lipase, fatty acid hydrolase, monoacylglycerol lipase and endocannabinoid CB1 receptor in the dorsal vagal complex and stomach of rats exposed to a motion sickness protocol. The results showed that dexamethasone lowered the motion sickness index and restored the levels of endogenous cannabinoids and the expression of the endocannabinoid CB1 receptor, which declined after the induction of motion sickness, in the dorsal vagal complex and stomach.