kaolinite and Motion-Sickness

Motion sickness (MS) is an acute disorder that occurs in healthy individuals worldwide regardless of gender, age, or ethnicity. Our study used a mouse model to rule out the effects of any psychological factors related to MS and EA. Subjects were randomly separated into four groups, namely the control group (Con), motion sickness inducing group (MS), mentioning sickness inducing with electroacupuncture treatment group (EA) and motion sickness inducing only in TRPV1 knockout mice group (TRPV1

Topics: Animals; Brain Stem; Disease Models, Animal; Electroacupuncture; Extracellular Signal-Regulated MAP Kinases; Gene Deletion; Hypothalamus; Kaolin; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Motion Sickness; NF-kappa B; Signal Transduction; Thalamus; TRPV Cation Channels

We previously reported that motion sickness was prevented in rats with amygdala lesion and that provocative motion stimuli increased the number of Fos-positive neurons in the amygdala, suggesting that the amygdala is one of the neural substrates involved in the development of motion sickness. NK-1 receptors in the brain stem and amygdala are thought to play an important role in emesis and affective disorders, respectively. In the present study, to elucidate a role of substance P neuronal system and NK-1 receptors in the brain stem and amygdala in the development of motion sickness, we measured changes in gene expression of NK-1 receptors and preprotachykinin, a precursor of substance P, using quantitative real-time PCR methods in solitary tract nucleus and amygdala in rats after provocative motion stimuli induced by 2G hypergravity load. Effects of systemic administration of CP-99,994, an antagonist for NK-1 receptors, on hypergravity-induced motion sickness were also examined using pica behavior, eating non-nutritive substances such as kaolin, as an index of motion sickness in rats. Hypergravity-induced motion sickness was inhibited by CP-99,994 with a dose-dependent and enantioselective manner. Preprotachykinin mRNA expression was increased in basolateral nucleus of amygdala and solitary tract nucleus after hypergravity load for 3h, whereas NK-1 receptor mRNA expression was not changed by hypergravity in amygdala and solitary tract nucleus. Present results suggest that 2G hypergravity load activated the substance P neuronal system in amygdala as well as in the brain stem and this activation would be related to the development of motion sickness.

Topics: Amygdala; Analysis of Variance; Animals; Brain Stem; Disease Models, Animal; Eating; Gene Expression Regulation; Hypergravity; Kaolin; Male; Motion Sickness; Neurokinin-1 Receptor Antagonists; Piperidines; Protein Precursors; Rats; Rats, Wistar; Receptors, Neurokinin-1; RNA, Messenger; Tachykinins; Time Factors

Topics: Animals; Disease Models, Animal; Drug Evaluation, Preclinical; Ear, Inner; Habituation, Psychophysiologic; Injections; Kaolin; Mice; Motion Sickness; Reproducibility of Results; Rotation; Vestibule, Labyrinth

To determine the influence of gravity during critical periods of development is important in the perspective of long-term spaceflight and exploration, data coming from this kind of studies providing insight into basical biological phenomena underlying the development of the nervous system and its plasticity. Aim of the present study was to evaluate neurobehavioural responses to hypergravity exposure in CD-1 mice at different stage of development. Early adolescent (postnatal day 28, PND 28), adolescent (PND 42) and young-adult (PND 60) male and female mice were exposed to acute 2g rotational-generated hypergravity. Motion sickness index and behavioural performances pre, during and after rotation were recorded, and long-lasting effects on exploratory behaviour (hole-board test) and emotional/anxiety-like responses (plus-maze test) were investigated. Furthermore, in order to correlate behavioural changes with alterations in central levels of neurotrophins, brain amounts of Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF) were also assessed on PND 90, following a re-exposure to hypergravity. Age and sex differences were observed, females being more vulnerable than males to motion sickness, and susceptibility to hypergravity increasing with age of exposure. Moreover, mice showed a general reduction in spontaneous activity during the rotation, while recovery time after rotation became progressively longer with increasing age of the experimental subjects. Long-term effects on exploratory behaviour and emotional/anxiety-like response were also observed, behavioural profiles mainly changing in those animals experiencing hypergravity as young-adults. Finally, major changes in brain levels of NGF and BDNF were detected in mice firstly exposed as young-adults.

Topics: Adaptation, Physiological; Age Factors; Analysis of Variance; Animals; Anxiety; Behavior, Animal; Brain; Brain-Derived Neurotrophic Factor; Chi-Square Distribution; Exploratory Behavior; Feeding Behavior; Female; Hypergravity; Kaolin; Male; Mice; Motion Sickness; Motor Activity; Nerve Growth Factor; Psychophysiology; Sex Factors

To study whether rotational stimulus induced pica and whether the vestibular apparatus was necessary for obtaining rotation-induced pica in mice.. Pica behavior in mice was investigated following 60 min of rotation once daily at 70 rpm (15 s on with 5 s off) for 3 consecutive days. After evaluating vestibular function and histology of vestibular epithelia, we examined rotation-induced kaolin intake, so-called pica, in sham-lesioned and chemically labyrinthectomized mice.. The labyrinthectomized mice exhibited loss of the contact righting and swimming capability while the destruction of hair cells of vestibular epithelia was observed. Moreover, mice subjected to rotation, but not labyrinthectomized mice, showed a significant increase in kaolin intake at the last 2 rotation sessions and the first postrotation session.. The findings indicated that a functioning vestibular system is necessary for rotation-evoking pica in mice and thus pica can be a behavioral index of motion sickness in mice.

Topics: Animals; Behavior, Animal; Eating; Female; Kaolin; Mice; Mice, Inbred Strains; Motion Sickness; Pica; Rotation; Vestibule, Labyrinth

To assess the specification and efficiency of rotation sickness indices by monitoring changes of behaviors in rats under rotation stimulation.. SD rats were stimulated by Crampton model with different time courses. Pica or kaolin consumption (KC), conditioned taste aversion (CTA) or saccharine water ingestion (SWI), 2 h food ingestion (2hFI), and open-field test (OFT) scores were observed.. Apparent changes of the four indices were observed after rotation stimulation. SWI, OFT scores and 2hFI decreased exponentially with increase of duration of the motion stimulation. KC increased linearly with the increase of time within 12 h stimulation. After 18 h stimulation, KC decreased to a level even lower than that after 6 or 12 h stimulation. The adjusted correlation between changes of the indices and duration of stimulation within 12 h are: 0.94 for KC, 0.54 for SWI, 0.44 for 2hFI and 0.34 for OFT. The maximum efficiency of the four indices appeared at 6-hour stimulation: 70% for KC, 90% for SWI, 80% for 2hFI and 95% for OFT.. It is found that pica and CTA were more specific than the other indices. They may serve as primary indices and can be combined with the secondary indices such as 2hFI or OFT. Six hours is the optimal duration of stimulation by Crampton model for rotation sickness studies.

Topics: Animals; Aversive Therapy; Behavior, Animal; Disease Models, Animal; Eating; Kaolin; Motion Sickness; Pica; Rats; Rats, Sprague-Dawley; Rotation; Saccharin; Taste; Time Factors; Water; Weightlessness Simulation

To evaluate the behavioural response to a hypergravity condition in CD-1 mice, young adult subjects of both sexes were exposed to 2 g for a single 60 min rotational session. Motion sickness (MS) and ethological-type scoring of different activities were used to evaluate the behavioural response. Nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) levels were also assessed. Behavioural scores indicated a transient mild sickness associated with hypergravity, with reduction in spontaneous activity. In males kaolin consumption (a MS index) increased following rotation while females consumed more kaolin irrespective of whether they have been rotated or simply exposed to the noise and vibration of the rotational apparatus. In males, hypothalamic NGF levels were markedly increased after rotation while no major changes were observed in central BDNF expression. These results indicate mice may represent a suitable MS model.

Topics: Animals; Behavior, Animal; Brain; Eating; Female; Hypergravity; Kaolin; Male; Mice; Motion Sickness; Nerve Growth Factor; Nervous System Physiological Phenomena; Pica; Rotation; Sex Characteristics; Tissue Distribution

Objective. To test the validity of an animal model in selecting anti-motion sickness drugs, and compare the effects of two drugs. Method. Anti-motion sickness effects of two drugs (Cyclizine and Scopolamin-d-amphetamin compound) were observed in rats with motion sickness (MS) induced by rotatory stimulation and the amount of Kaolin ate by rats was taken as an evaluation criterion. Result. The consumption of Kaolin by the rats decreased significantly after administration of both drugs, and the effect of Scopolamin-d-amphetamin compound was better than those of Cyclizine under the same condition. Conclusion. It suggests that the rat model of motion sickness is practical and useful in studying anti-motion sickness drugs.

Topics: Animals; Antiemetics; Central Nervous System Stimulants; Cyclizine; Dextroamphetamine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Combinations; Kaolin; Motion Sickness; Pica; Rats; Scopolamine

The effects of diphenhydramine, domperidone, ondansetron, and diphenidol on motion- and apomorphine-induced pica (i.e., kaolin ingestion) in rats as the measure analogous to emesis in other species were examined. Diphenhydramine (10 and 20 mg/kg) and diphenidol (30 mg/kg) inhibited kaolin intake induced by 60-min double rotation, while domperidone and ondansetron did not. Kaolin intake induced by apomorphine (10 mg/kg) was inhibited by domperidone (2 mg/kg) and diphenidol (30 mg/kg), but not by diphenhydramine or ondansetron. These findings suggest that the emetic pathways through the inner ear (double rotation) and the chemoreceptor trigger zone (apomorphine) are pharmacologically independent and are mediated by histamine H1 receptors and dopamine D2 receptors, respectively. Diphenidol may inhibit a common locus of emesis.

Topics: Animals; Antiemetics; Apomorphine; Diphenhydramine; Domperidone; Eating; Kaolin; Male; Motion Sickness; Pica; Rats; Rats, Wistar; Time Factors

The characteristics of linear acceleration to cause motion sickness of rats were examined using pica as a behavioral index of motion sickness. A vestibular sled was used to generate sinusoidal linear acceleration. At 0.4 Hz and with a peak acceleration of 0.15 G, the effectiveness of linear acceleration in inducing motion sickness was X-axis > Y-axis > Z-axis. At 0.4 Hz and along the X-axis, rats suffered from more severe motion sickness with a high peak G load (0.15 G) than with a low one (0.08 G). Along the X-axis and with a peak acceleration of 0.15 G, the severity of motion sickness was not related to frequency (0.4, 0.6 Hz).

Topics: Acceleration; Animals; Eating; Kaolin; Male; Motion Sickness; Movement; Rats; Rats, Wistar; Rotation; Saccule and Utricle; Semicircular Canals

Using kaolin intake as a behavioral index of emesis in rats, we examined the relationship between susceptibility to motion sickness and to emesis induced by apomorphine or copper sulfate. Rats showed a wide variation in susceptibility to motion sickness. Significant positive correlations were found between susceptibility to motion sickness and to emesis induced by intraperitoneal administration of apomorphine and by oral administration of copper sulfate. Motion, apomorphine and copper sulfate induce emesis through different receptors, so these findings suggest that the sensitivity of a common locus of emesis, presumably the emetic center in the brain stem, is one determinant of individual differences in susceptibility to motion sickness.

Topics: Animals; Apomorphine; Brain; Copper; Copper Sulfate; Disease Susceptibility; Kaolin; Male; Motion; Motion Sickness; Pica; Rats; Rats, Wistar; Sensory Thresholds; Stomach; Vestibule, Labyrinth; Vomiting

Pica, the eating of nonnutritive substances such as kaolin, can be induced by rotation in rats. We used this rotation-induced pica as a behavioral index of motion sickness in rats and examined whether diphenhydramine, methamphetamine and scopolamine, which are anti-motion sickness drugs for humans, are effective for reducing motion sickness in rats. Intraperitoneal injection of diphenhydramine or methamphetamine suppressed the rotation-induced kaolin intake of rats. Intraperitoneal injection of scopolamine had no effect on the rotation-induced kaolin intake, but its transdermal administration reduced this kaolin intake. These findings show that human anti-motion sickness drugs also prevent motion sickness in rats. Since the pharmacological mechanisms for preventing motion sickness in rats and humans are similar, we conclude that rats are a suitable animal model for use in studies on putative anti-motion sickness drugs.

Topics: Animals; Diphenhydramine; Kaolin; Male; Methamphetamine; Motion Sickness; Pica; Rats; Rats, Inbred Strains; Rotation; Scopolamine

The appropriateness of kaolin consumption, one form of pica, as an index of motion sickness in the rat was examined. Unlike other motion sickness indices, the use of kaolin consumption results in a bitonic function across daily rotation sessions. This bitonic function is not predicted from any theory of motion sickness (viz., the Sensory Rearrangement Theory), rather an inverse relationship should exist between the severity of motion sickness and repeated exposure to the effective motion (i.e., habituation). The results of Experiments 1 and 2 support the continued use of kaolin consumption as an index of motion sickness in the rat. A response interference process is proposed to account for the first portion of the bitonic kaolin consumption function with grooming possibly representing a higher probability behavior than kaolin consumption. Experiment 3 examined and confirmed that kaolin consumption indexes the process of rehabituation to an effective motion. This extends the number of principles that are characteristic of motion sickness exhibited by species capable of emesis and supports the continued use of kaolin consumption as an index of motion sickness and general gastrointestinal malaise in the rat.

Topics: Animals; Behavior, Animal; Kaolin; Male; Motion Sickness; Pica; Rats; Rotation

The relationship between motion sickness and age was examined in three groups of male rats in order to determine whether or not age related differences in susceptibility are due to experiential factors or unspecified changes in the central nervous system. The results revealed no difference in susceptibility between 2-month old and 11-month old group. However, the 20-month old group was significantly less susceptible to motion sickness than either of the other groups. These findings indicate that general age related changes in the central nervous system are more likely to account for the relationship between motion sickness and age tha are experiential factors.

Topics: Aging; Animals; Brain; Habituation, Psychophysiologic; Kaolin; Male; Motion Sickness; Rats

Two experiments investigating the effects of motion sickness on pica (the consumption of non-nutritive substances) are reported. In the first experiment rats subject to rotational stimulation subsequently engaged in geophagia (clay consumption). In the second experiment use of a conditioned aversion paradigm confirmed that the method of rotational stimulation used in the first experiment causes motion sickness in rats. The results of these experiments indicate that simple gastrointestinal malaise in the absence of a deficiency state or acute toxemia will elicit pica. It is suggested that gastrointestinal distress may be a significant factor in the etiology of pica and its relationship to other causes of pica is discussed.

Topics: Animals; Eating; Gastrointestinal Diseases; Humans; Kaolin; Male; Motion Sickness; Pica; Rats

Topics: Animals; Behavior, Animal; Disease Models, Animal; Habituation, Psychophysiologic; Humans; Kaolin; Male; Motion Sickness; Pica; Rats; Rotation; Species Specificity; Vomiting