Immobility Response Research Articles

The Effect of Metoclopramide on the Antinociceptive, Locomotor and Neurobehavioral Effects of Metamizole in Mice

Abstract Combining analgesic medications with distinct pharmacodynamics may result in effective analgesia and reduced adverse effects by lowering dosages of one or both medications. The objective was to investigate the nature of interactions of metoclopramide and metamizole by measuring the antinociceptive and neurobehavioral effects in mice. The drugs were administered intraperitoneally (ip) in mice. The antinociceptive effect was determined by the up-and-down method. Isobolographic analysis was performed by simultaneous injection of the two drugs at ED50 ratios of 1:1 and 0.5:0.5. The treated mice were also subjected to an open-field behavioral test as well as dorsal immobility and negative geotaxis behavioral paradigms. The ED50 of metoclopramide and metamizole were 33.71 and 43 mg/kg ip, respectively. Lower ED50 was established for metoclopramide and metamizole by 48.44% and 47.49%, respectively when given at a ratio of 0.5:0.5, and by 35.81% and 29.88%, respectively at a ratio of 1:1. The combined dose of metoclopramide and metamizole (8 and 10 mg/kg, ip, respectively) significantly decreased the open field-activity test in mice. This was observed by lower number of squares crossing compared to the control. Additionally, the drug combination resulted in a substantial increase in the duration of dorsal immobility response and delayed the negative geotaxis task when compared with the control group. The results indicated that the interaction between metoclopramide and metamizole in lower dose ratio with ED50 50:50, was synergistic in producing analgesia in mice with reduced risk for adverse reaction but with decreased behavioral and motor neuronal activity.

Tonic immobility triggered by COVID-19-related trauma is associated with long-term PTSD symptoms

During the COVID-19 pandemic healthcare workers were repeatedly exposed to traumatic experiences. Facing life-threatening events and repeated exposure to traumatic duty-related situations may cause posttraumatic stress disorder (PTSD). While tonic immobility has been considered a key vulnerability factor for PTSD, little is known about this relationship in the long term. In this study, we aimed to determine whether peritraumatic tonic immobility triggered by COVID-19-related trauma predicts PTSD symptom severity six to twelve months later. We conducted an online longitudinal survey using the PTSD Checklist for the DSM-5 (PCL-5) and the Tonic Immobility Scale to assess PTSD symptoms and the tonic immobility response, respectively. Multivariate regression models revealed a significant association between tonic immobility and PTSD symptoms. Each one-unit increase in the tonic immobility score was associated with a 1.5 % increase in the average PTSD symptom score six to twelve months after the traumatic event that triggered the tonic immobility. Furthermore, participants who showed significant or extreme levels of tonic immobility were 3.5 times or 7.3 times more likely to have a probable PTSD diagnosis, respectively. Hence, peritraumatic tonic immobility seems to have a lasting deleterious effect on mental health. Psychological treatment for health care professionals is urgent, and psychoeducation about the involuntary, biological nature of tonic immobility is essential to reduce suffering.

Propolis prevents vascular endothelial dysfunction by attenuating inflammation and oxidative damage in the chronic unpredictable stress model of depression in rats.

Chronic stress may lead to depression and vascular endothelial dysfunction. We aimed to evaluate the effects of propolis on vascular functions and the possible mechanisms of its vascular effects in the rat model of chronic unpredictable mild stress (CUMS)-induced depression. Male Wistar rats were divided into control, stress (exposure to CUMS), control+propolis and stress+propolis groups (n = 8/each group). CUMS model was induced by exposing rats to various mild stressors daily for 5 weeks. The extract of propolis (100 mg/kg/day) was administered orally to propolis-treated groups for 5 weeks. The depression-like behaviours were assessed with the forced swimming test (FST). Chronic stress resulted in increased immobility response in FST and elevated serum corticosterone levels. Thoracic endothelial functions and expressions of endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha (TNFα), interleukin-1beta (IL-1β), Heme oxygenase-1 (HO-1) and superoxide dismutase (SOD) level were assessed. Compared to control group, stress group exhibited a significant decrease in endothelium-dependent relaxations, and eNOS, SOD and HO-1 expressions, whereas a significant increase in the thoracic expressions of TNFα and IL-1β. Propolis ameliorated depression-like behaviours, vascular endothelial dysfunctions and alterations of protein expressions. Propolis exerted antidepressant-like and vasculoprotective effects in CUMS-induced depression in rats. Chronic propolis treatment may have a protective effect on CUMS-induced vascular endothelial dysfunction by its anti-inflammatory and antioxidant effects.

Differences among domestic chicken breeds in tonic immobility responses as a measure of fearfulness.

One priority for animal welfare is for animals to experience less fear, especially during human contact. For domestic animals, breeds that are less fearful may provide genetic resources to develop strains with improved welfare due to lower susceptibility to fear. Genetic predispositions inherited in these breeds might reflect the large diversity of chicken breeds. The goal of the present study was to systematically test a diverse group of chicken breeds to search for breeds that experience less fear. Nineteen chicken breeds from commercial hybrid lines, native layer-type, meat-type and dual-purpose breeds, ornamental breeds as well as bantam breeds were tested in a standardized tonic immobility (TI) test. Chickens were manually restrained on their back, and the time to first head movement and first leg movement, the duration of TI, as well as the number of attempts needed to induce TI were measured. The TI response differed among chicken breeds (p≤0.001) for naïve, mature hens. The median number of attempts required to induce TI ranged from 1 to 2 and did not differ significantly among breeds. Median durations were much more variable, with Lohmann Brown showing shortest durations (6 s, 12 s, 58 s for time to first head movement, first leg movement and total duration of TI, respectively). In contrast, medians reached the maximum of 600 s for all three measures in German Creepers. Repeated tests on the same individuals did not affect attempts needed to induce TI nor TI durations. Breeds clustered into two main groups, with layer-type native breeds and ornamental breeds having longer TI durations, and bantam, dual-purpose and meat-type native breeds having shorter TI durations. Our findings provide evidence for substantial variation of fearfulness among breeds. This variation could be linked to the intended use during the breed's specific history. Knowledge and quantitative measurement of these behavioural responses provide the opportunity to improve welfare through selection and future breeding.

Pain control in tonic immobility (TI) and other immobility models.

This chapter deals with the mechanisms modulating pain during TI and other immobility responses in different animal species. In mammals the presence of high voltage slow waves in the electroencephalogram during TI suggests the activation of the thalamic gate, a mechanism blocking all sensory information, including pain. In rabbits TI transiently suppresses all the behavioral responses to persistent nociceptive stimulation by the activation of an opioid mechanism outlasting TI offset by 1h. On the other hand, in rodents, also not injuring nociceptive stimuli applied during TI elicit a delayed opioid analgesia that develops within 45min. Moreover, both opioid and non-opioid mechanisms of analgesia have been observed. TI strongly reduces inflammatory responses by activating the vagal-neocortical-sympathetic axis, a feedback control of neuro-immune mechanisms. Several models of noxious and non-noxious restraint and of post-restraint immobility resembling TI have been proposed. Moreover in lizards, hyperalgesia occurs during and after TI.

Defensive responses in invertebrates: Evolutionary and neural aspects.

Lower invertebrates exhibit both morphological and behavioral defensive responses to aversive stimuli, characterized by withdrawal. Typical immobility responses are "sinking" in Rotifers and "crumpling" in Cnidaria. They also display individual adaptation and phenotypic plasticity but not tonic immobility (TI). The higher phyla with a more organized nervous system have developed morphological and behavioral defensive strategies including TI, occurring both in natural and laboratory conditions. There are general but also specific prey-predator mechanisms, that have coevolved leading to reciprocal phenotypic plasticity. The evolution of traits differentiated in subpopulations has been described in many species (animal personality). In insects the variability in TI is heritable and inversely related to boldness. In two genetic lines of beetles with long and short TI duration, the long duration line has higher survival rate but lower mating success (behavioral syndromes). TI may have an adaptive significance also in intraspecific interactions in the context of sexual selection.

Effect of nefopam in normal chickens and its relationship to hydrogen peroxide-induced oxidative stress

The objective designated to discover the analgesic effect of nefopam in the normal (non-stressed) chickens and its possible alteration due to hydrogen peroxide (H2O2)-induced oxidative stress (OS) in 7-14 day old chickens. The analgesia of nefopam has been increased by 47% in the stressed chickens by measuring the analgesic Median Effective Dose (ED50) value. This value was 9.10 mg/kg, IM in the normal chickens where it became 4.80 mg/kg, IM in stressed chickens. There is a significant rise in the antinociceptive action of nefopam 18 mg/kg, IM by 88% in the stressed group of chickens in comparison with the normal one elicited by an electro-stimulation and formaldehyde 0.05 ml of 0.1% tests for induction of nociception. The observations showed several significant stimulatory modifications in the neurobehaviour when nefopam treated with a subtle dosage 1 mg/kg, IM in the stressed chickens concerning the latency to move, squares crossed and time of the tonic immobility response test. Significant damage was detected in the liver function when nefopam injected at 18 mg/kg, IM in stress chickens in comparison to normal one by 28, 33 and 65% as estimated through Alkaline phosphatase (ALP), Aspartate trans-aminase (AST) and Alanine trans-aminase (ALT) concentrations in the serum, respectively. The sum of data findings indicated that H2O2-inducedOS increased the analgesic activity of nefopam in the chickens; despite the changes occur on the neurobehaviour and liver function. The dose of nefopam should be reduced when preparing the therapeutic regimen in the stressed animals.

Prophylactic effects of dietary ascorbic acid on oxidative stress indices, physiological and behavioural responses of domestic pigeons exposed to road transport stress.

Transport disturbs birds’ welfare and health status which lead to oxidative stress and dietary ascorbic acid mitigates the adverse effects of transport stress. The present study was aimed to evaluate the impacts of ascorbic acid administration on oxidative stress indices, cortisol, H/L ratio, tonic immobility reaction and rectal temperature of pigeons exposed to road transport. A total of 80 clinically healthy pigeons were selected and randomly divided to eight equal groups as follow: (1) Ctrl–: fed by basal diet and no subjected to transport stress; (2) Ctrl+: fed by the basal diet and subjected to transport stress; (3, 4) 1DBS10 and 1DBS16: received ascorbic acid from 1 day before transport stress at doses of 10 g/100 L and 16 g/100 L of drinking water, respectively; (5, 6) 3DBS10 and 3DBS16: treated with ascorbic acid from 3 consecutive days before transport stress at doses of 10 g/100 L and 16 g/100 L, respectively and (7, 8) 7DBS10 and 7DBS16: received ascorbic acid from 7 consecutive days before the transport at doses 10 g/100 L and 16 g/100 L, respectively. Birds were transported for 3 h over a distance of about 200 km. The total antioxidant capacity, malondialdehyde and cortisol were measured before transport and at 6, 24 and 72 h post‐transportation. The rectal temperature and tunic immobility reactions were recorded. Dietary ascorbic acid led to a decrease in tonic immobility response, hetrophil to lymphocyte ratio, circulating cortisol and total antioxidant capacity, and an increase in circulating malondialdehyde in pigeons exposed to transport stress compare to Ctrl+ group. In conclusion, ascorbic acid administration at dose 16 g/100 L of drinking water from 3 and 7 days before exposure to stress helps attenuate undesirable effects of oxidative stress in pigeons.

The immobility-relocation continuum: Diverse responses to coastal change in a small island state

Rising sea levels and associated coastal hazards will lead to the relocation of some communities away from sites of high exposure. In Fiji, several communities have already initiated relocation, with hundreds more considered in need of future relocation by the Fijian government. Yet, often relocation is viewed as an inevitable response to coastal exposure, whereby an entire community is relocated from one location (of high exposure) to another (of lesser exposure) with the assistance of an external actor, namely the State and donors. Limited research has drawn attention to the heterogenous nature of relocation (and immobility responses), and the factors that shape these diverse processes. Drawing on fieldwork undertaken across seven low-lying communities in Fiji that are facing exposure to coastal erosion, tidal inundation, and storm surges, we highlight different immobility and relocation responses that are being implemented both within and across villages. These responses can be viewed along a continuum, referred to here as the immobility-relocation continuum, and include: voluntary immobility, immobility due to restricted relocation options, incremental relocation, partial relocation, and full community relocation. We identify factors - climatic and environmental, past and current adaptations and mobilities, socio-cultural, land rights and tenure, and institutional – that shape these varied responses. This research underscores the need to expand our thinking regarding how climate-related relocation is conceptualized and implemented in policy and practice toward a nuanced understanding of (im)mobility as a form of adaptation to coastal hazard risks, accounting for diversity in local conditions, preferences, and resources available to communities.

Tonic Immobility is Associated with PTSD Symptoms in Traumatized Adolescents.

PurposeGrowing evidence suggests that peritraumatic tonic immobility, an involuntary defensive response that involves extreme physical immobility and the perceived inability to escape, is a significant predictor of post-traumatic stress disorder (PTSD) symptomatology. However, this issue has not been specifically addressed in adolescents. Here, we investigated whether tonic immobility response experienced during the worst childhood or adolescent trauma is associated with PTSD symptom severity in a non-clinical student sample.MethodsThe sample was composed of students in 9th grade who were attending public and private schools. Symptoms of post-traumatic stress and tonic immobility were assessed using questionnaires. We performed bivariate and multivariate negative binomial regressions to examine whether tonic immobility was associated with PTSD symptomatology after controlling for confounders (peritraumatic dissociation, peritraumatic panic reactions, gender, age and time since trauma).ResultsWe found an association between tonic immobility and PTSD symptom severity, even after controlling for confounders. Therefore, tonic immobility is associated with PTSD symptoms in trauma-exposed adolescents.ConclusionThese findings highlight tonic immobility as a possible risk factor that could be used to provide direction for more targeted trauma interventions for individuals, particularly those at risk for developing PTSD. Therefore, it contributes to preventing and reducing the psychiatric burden in adolescence and later in life.

Drosophila females receive male substrate-borne signals through specific leg neurons during courtship

SummarySubstrate-borne vibratory signals are thought to be one of the most ancient and taxonomically widespread communication signals among animal species, including Drosophila flies.1, 2, 3, 4, 5, 6, 7, 8, 9 During courtship, the male Drosophila abdomen tremulates (as defined in Busnel et al.10) to generate vibrations in the courting substrate.8,9 These vibrations coincide with nearby females becoming immobile, a behavior that facilitates mounting and copulation.8,11, 12, 13 It was unknown how the Drosophila female detects these substrate-borne vibratory signals. Here, we confirm that the immobility response of the female to the tremulations is not dependent on any air-borne cue. We show that substrate-borne communication is used by wild Drosophila and that the vibrations propagate through those natural substrates (e.g., fruits) where flies feed and court. We examine transmission of the signals through a variety of substrates and describe how each of these substrates modifies the vibratory signal during propagation and affects the female response. Moreover, we identify the main sensory structures and neurons that receive the vibrations in the female legs, as well as the mechanically gated ion channels Nanchung and Piezo (but not Trpγ) that mediate sensitivity to the vibrations. Together, our results show that Drosophila flies, like many other arthropods, use substrate-borne communication as a natural means of communication, strengthening the idea that this mode of signal transfer is heavily used and reliable in the wild.3,4,7 Our findings also reveal the cellular and molecular mechanisms underlying the vibration-sensing modality necessary for this communication.

Forced swim stressor: Trends in usage and mechanistic consideration.

The acquired immobility response during the “forced swim test (FST)” is not a rodent model of depression, but the test has some validity in predicting a compound's antidepressant potential. Nevertheless, 60% of the about 600 papers that were published annually the past 2 years label the rodent's immobility response as depression‐like behaviour, but the relative contribution per country is changing. When the Editors‐in‐Chief of 5 journals publishing most FST papers were asked for their point of view on labelling immobility as depression‐like behaviour and despair, they responded that they primarily rely on the reviewers regarding scientific merit of the submission. One Editor informs authors of the recent NIMH notice (https://grants.nih.gov/grants/guide/notice‐files/NOT‐MH‐19‐053.html) which encourages investigators to use animal models “for” addressing neurobiological questions rather than as model “of” specific mental disorders. The neurobiological questions raised by use of the FST fall in two categories. First, research on the role of endocrine and metabolic factors, with roots in the 1980s, and with focus on the bottom‐up action of glucocorticoids on circuits processing salient information, executive control and memory consolidation. Second, recent findings using novel technological and computational advances that have allowed great progress in charting top‐down control in the switch from active to passive coping with the inescapable stressor executed by neuronal ensembles of the medial prefrontal cortex via the peri‐aquaductal grey. It is expected that combining neural top‐down and endocrine bottom‐up approaches will provide new insights in the role of stress‐coping and adaptation in pathogenesis of mental disorders.

Mobilidade e vulnerabilidade socioambiental: um estudo de caso para Governador Valadares, Minas Gerais, Brasil

Mobility or immobility responses to environmental issues are likely to be associated with socio-environmental characteristics and vulnerability of families and the context, and these responses may be a mechanism of adaptation (to environmental events) and reduction or aggravation of vulnerability. In addition, the speed and severity of environmental events may impose the adoption of mobility on individuals. For this purpose, a socio-environmental vulnerability index and mobility typologies were constructed using data from a probabilistic, mutli-stage sample of 1226 urban households collected between 2013 and 2016. The results suggest that although the subgroup of respondents with international mobility experiences is more exposed to socio-environmental risks, it is better able to adapt to the occurrence of socioenvironmental problems and has smaller levels of vulnerability than the subgroup of respondents that has never experienced international mobility.

Cell Proliferation in the Adult Chicken Hippocampus Correlates With Individual Differences in Time Spent in Outdoor Areas and Tonic Immobility.

Access to outdoor areas is provided as a means of enhancing welfare in commercial systems for laying hens (Gallus gallus domesticus), but substantial individual differences exist in their proportional use. Baseline cell proliferation levels of Adult Hippocampal Neurogenesis (AHN) have been associated with individual differences in reactive vs. proactive coping style, and in both mammals and birds, AHN is upregulated by positive experiences including environmental enrichment and exercise. We thus sought to explore whether individual differences in use of outdoor areas and in tonic immobility responses (indicative of fearfulness) were associated with hippocampal cell proliferation and neuronal differentiation. Radio frequency identification technology was used to track the ranging behavior of 440 individual focal hens within a commercially-relevant system over a 72-days period, after which tonic immobility durations were measured. Following hippocampal tissue collection from 58 focal hens, proliferation and neuronal differentiation were measured through quantitative PCR for proliferating cell nuclear antigen (PCNA) and doublecortin mRNA, respectively. Individual differences in tonic immobility duration positively correlated with PCNA expression over the whole hippocampal formation, while greater time spent in outdoor areas (the grassy range and stone yard) was associated with higher proliferation in the rostral subregion. Basal proliferation in the chicken hippocampal formation may thus relate to reactivity, while levels in the rostral region may be stimulated by ranging experience. Doublecortin expression in the caudal hippocampus negatively co-varied with time on the grassy range, but was not associated with tonic immobility duration. This suggests that ranging outside may be associated with stress. Within laying hen flocks, individual differences in hippocampal plasticity thus relate to coping style and use of external areas.

Immobility Responses Affected by Potassium in Old Rats

Four immobility responses (IR): elicited by clamping, bandaging, grasping and inversion, and their modification by potassium and spironolactone was studied in old Wistar rats (body weight, 500 g). When undrugged, only clamping and grasping, but not bandaging and inversion induced an IR in rats. Potassium and spironolactone significantly enhanced the duration of IR induced by clamping but not by grasping. They also induced an immobility response by bandaging, but not by inversion. The data suggest that IR induced by clamping and bandaging are somehow related to changes in the potassium serum levels. Consequently, such a relationship may be a suitable model to study some forms of paralysis in human beings which are related to changes in the potassium serum levels.

Comorbid sensorimotor and emotional profiles in the forced swim test immobility and predictive value of a single assay in very old female mice.

The increase of prevalence of mental health problems in the elderly due to the aging of the population becomes an outstanding issue since in most individuals it happens in an already complex multimorbid scenario that may include frailty and age-related medical conditions. Depression, soon the major cause of global disease burden, can be found as an age-related comorbidity and frailty, or as part of neurodegenerative diseases and where females are more vulnerable to it. Thought the multifactorial aetiology and heterogeneous nature of depression render it difficult to be modelled in animals, active behaviours elicited in the Forced Swimming Test (FST) are used to screen antidepressant treatments. However, interpretation of immobility remains controversial. The present work addressed this issue in very-old (21 months) female C57bl/6 × 129 mice, also with the concern that a '6 minutes × 2 days' protocol can result demanding for a very-old animal and confounding factors may also arise. Animals were behaviourally assessed for sensorimotor functions, emotionality and anxiety-like behaviours, novelty seeking, and immobility in a 2-days FST. The predictive value of the first day evidenced that one single assay as sufficient for the assessment of immobility, and that the repeated test did not increase the immobility response. Moreover, sensorimotor tasks, neophobia in the corner test and emotional behaviour in the dark-light box correlated with FST immobility, contributing to the response. The results support the concern of geroscience on the relevance of using aged animals but also aware about taking into account the complexity of their comorbid scenario.

Assessing Post-Traumatic Tonic Immobility Responses: The Scale for Tonic Immobility Occurring Post-Trauma

Background Peri-traumatic tonic immobility has been associated with the development and course of post-traumatic stress disorder. Despite serving as an adaptive late-stage defense response, tonic immobility that continues in response to post-traumatic reminders may lead to reduced functioning and a diminished sense of well-being. At present, no validated self-report measures assess post-traumatic tonic immobility responses specifically. Methods The primary objective of the present study was to evaluate the Scale for Tonic immobility Occurring Post-trauma (STOP), the first self-report measure developed to assess for the presence and severity of tonic immobility responses that persist following trauma exposure as part of post-traumatic symptomatology. Trauma-exposed clinical and non-clinical participants (N = 462) with a history of tonic immobility completed a demographic questionnaire, the STOP, and measures of post-traumatic symptoms, dissociation, anxiety, and depression. Results STOP assessed four latent constructs, which were interpreted following the human defense cascade model. Together, these factors capture the sensorimotor and perceptual alterations, and dissociative experiences, associated with post-traumatic tonic immobility as a trauma-related altered state. Residual symptoms and the experience of negative affect following this response (including guilt and shame) are also represented. STOP scores demonstrated excellent reliability, as well as good construct and convergent validity, with other measures of dissociation and post-traumatic stress disorder. Results from the present study suggest tonic immobility is most consistent with other dissociative post-traumatic symptomatology. Conclusions STOP demonstrates excellent preliminary psychometric properties and may be useful for researchers and clinicians wishing to assess chronic forms of tonic immobility across trauma-exposed, clinical and community samples.

Pain chronification and chronic pain impair a defensive behavior, but not the ability of acute pain to facilitate it, through the activation of an endogenous analgesia circuit.

The endogenous ability to decrease pain perception during life-threatening situations is crucial to the prevention of recuperative behaviors and to leave the subject free to engage in appropriated defensive responses. We have previously shown that acute pain activates the ascending nociceptive control-an endogenous analgesia circuit dependent on opioid mechanisms within nucleus accumbens-to facilitate the tonic immobility response, an innate defensive behavior. Now we asked whether chronic pain and pain chronification impairs either the tonic immobility response or the ability of acute pain to facilitate it by activating the ascending nociceptive control. We found a significant decrease in the duration of the tonic immobility response in rats during the induction and maintenance phases of the persistent mechanical hyperalgesia. This finding suggests that chronic pain and its development impair defensive responses. However, during the induction and maintenance phases of persistent hyperalgesia, the ascending nociceptive control activation, by a forepaw capsaicin injection, increased the tonic immobility response, an effect prevented by the blockade of μ-opioid receptors within nucleus accumbens. This finding suggests that pain chronification and chronic pain do not prevent the ability of acute pain to facilitate the defensive behavior of tonic immobility by activating the ascending nociceptive control. Therefore, although chronic pain states decrease the ability to engage in a defensive behavior, they may not prevent the expression of defensive behaviors during life-threatening situations accompanied by acute pain. The biological purpose of such a mechanism may be to increase the chances of survival of a wounded subject exposed to acute pain in a novel life-threatening situation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Immobility responses are induced by photoactivation of single glomerular species responsive to fox odour TMT

Fox odour 2,4,5-trimethyl thiazoline (TMT) is known to activate multiple glomeruli in the mouse olfactory bulb (OB) and elicits strong fear responses. In this study, we screened TMT-reactive odourant receptors and identified Olfr1019 with high ligand reactivity and selectivity, whose glomeruli are located in the posterodorsal OB. In the channelrhodopsin knock-in mice for Olfr1019, TMT-responsive olfactory-cortical regions were activated by photostimulation, leading to the induction of immobility, but not aversive behaviour. Distribution of photoactivation signals was overlapped with that of TMT-induced signals, but restricted to the narrower regions. In the knockout mice, immobility responses were reduced, but not entirely abolished likely due to the compensatory function of other TMT-responsive glomeruli. Our results demonstrate that the activation of a single glomerular species in the posterodorsal OB is sufficient to elicit immobility responses and that TMT-induced fear may be separated into at least two different components of immobility and aversion.

Tonic immobility during sexual assault-a common reaction predicting post-traumatic stress disorder and severe depression.

Active resistance is considered to be the 'normal' reaction during rape. However, studies have indicated that similar to animals, humans exposed to extreme threat may react with a state of involuntary, temporary motor inhibition known as tonic immobility. The aim of the present study was to assess the occurrence of tonic immobility during rape and subsequent post-traumatic stress disorder and severe depression. Tonic immobility at the time of the assault was assessed using the Tonic Immobility Scale in 298 women who had visited the Emergency clinic for raped women within 1month of a sexual assault. Information about the assault and the victim characteristics were taken from the structured clinical data files. After 6months, 189 women were assessed regarding the development of post-traumatic stress disorder and depression. Of the 298 women, 70% reported significant tonic immobility and 48% reported extreme tonic immobility during the assault. Tonic immobility was associated with the development of post-traumatic stress disorder (OR 2.75; 95% CI 1.50-5.03, p=0.001) and severe depression (OR 3.42; 95% CI 1.51-7.72, p=0.003) at 6months. Further, previous trauma history (OR 2.36; 95% CI 1.48-3.77, p<0.001) and psychiatric treatment history (OR 2.00; 95% CI 1.26-3.19, p=0.003) were associated with the tonic immobility response. Tonic immobility during rape is a common reaction associated with subsequent post-traumatic stress disorder and severe depression. Knowledge of this reaction in sexual assault victims is important in legal matters and for healthcare follow up.