Mevinphos (Mev) is an orgnophosphate insectide used for suicidal purposes in Taiwan; seizure and cardiovascular depression are commom syptoms observed in organophosphate-poisoned patients. The amygdala (AMG) is part of the limbic system and the basolateral nucleus of AMG (BLA) is one of the most seizure-prone brain structures. The central neucleus of AMG (CeA) is thought to play a central role in behavioral, physiological response and cardiovascular regulation. However, detailed mechanisms in Mev-induced seizure and cardiovascular depression by an action on AMG are lacking. Based on electroencephalographic (EEG) activity to indicate neuronal electrical activity and arterial blood pressure (AP) and heart rate (HR) to indicate cardiovascular responses, the present study investigated whether Mev acts on AMG to elicit seizure or cardiovascular depression. Microinjection of Mev into BLA of adult male Sprague-Dawley (SD) rats maintained under propofol anesthesia increased EEG activity in AMG, cortex and CA3 of hippocampus leading to seizure initiation; however AP, HR, respiration rate (RR) and the power density of low-frequency (LF) component of AP was not significantly changed. Microinjection of Mev into BLA also time-dependently increased protein level and mRNA of cytokines interleukin (IL)-12, IL-13, tumor suppressor factor alpha (TNF£\) and interferon gamma (IFN£^) and cyclooxygenase (COX) activity in AMG. Microinjection of Mev into CA3 induced less seizure activity in cortex and CA3 than that induced by microinjection of Mev into BLA. In addition, microinjection Mev into CA3 did not induce seizure in AMG. These results suggest that Mev acted on BLA to initiate limbic seizures. Intraperitoneal injection of muscarinic receptor antagonist atropine (ATR), which can pass the blood-brain barrier (BBB), activator of GABAergic neurotransmission midazolam (MDZ) or antiinflaamatory agent pentoxifylline (PTX) and Lisofylline (LSF), but not muscarinic receptor antagonist atropine methyl nitrate (AMN), which can not pass BBB, inhibited Mev-induced seizure and increase of cytokines in AMG by an action on BLA. Microinjection of ATR, COX-1 inhibitor naproxen (NPX) or COX-2 inhibitor NS-398, antiserum against receptor of IL-12, IL-13, TNF£\ or IFN£^, but not nicotinic receptor antagonist mecamylamine (MEL), into BLA inhibited Mev-induced seizure and increase of cytokines and COX activity in AMG by an action on BLA. However, caspase 3 activity and DNA fragmentation at AMG were not changed by microinjection of Mev into BLA. Microinjection of Mev into CeA induced a decrease in AP and RR leading to cardiovascular depression and an increase of power desity of LF, accompanied with insignificant HR and EEG activity change. Microinjection of Mev into CeA induced the time-dependently increase of caspase 3 activity and DNA fragmentation leading to apoptosis in AMG. Microinjection of ATR or caspase 3-dependent apoptosome inhibitor NS-3694, but not MEL, into CeA inhibited cardiovascular depression and the increase of caspase 3 activity and DNA fragmentation induced by Mev action on CeA. However, the levels of cytokines were not changed by Mev treatment. Intravenous injection of Mev did not induce changes of partial pressure of oxygen, blood flow and the level of superoxide anion in AMG. In addition, microinjection of Mev into BLA or CeA did not affect the level of superoxide anion in AMG. These results suggest that AMG mediates the initiation of seizure and cardiovascular depression induced by Mev. Furthermore, inflammation in BLA and apoptosis in CeA individually play an important role in Mev-induced seizure and cardiovascular depression.

Agtarap, Wright, Mlynski, Hammad, and Blackledge took an initial step in providing support for the predictive validity of a new conceptual analysis concerned with behavioral restraint - defined as active resistance against a behavioral impulse or urge. The current study was designed to partially replicate and extend findings from their study, employing a common film clip protocol and a procedure for inducing low- and high levels of fatigue. Analyses indicated that key cardiovascular (CV) responses rose with the evocativeness of the film clip among low fatigue participants but fell with the evocativeness of the film clip among high fatigue participants. This is consistent with the prediction that high fatigue participants would put forth more restrain intensity than low fatigue participants when confronted with the less evocative clip, but less restraint intensity than low fatigue participants when confronted with the more evocative clip. Behavioral restraint performance - quantified as duration of facial non-neutrality - was also consistent with predictions, being impaired by fatigue under high- but not low evocativeness conditions. Findings support the broad theoretical suggestion that fatigue influence on behavioral restraint is multifaceted, dependent on the perceived magnitude of the impulse or urge experienced and the importance of resisting it.

These studies investigated the impact of intensity and body temperature on performance and cardiovascular regulation during high intensity and prolonged exercise. In study 1, polyphenol antioxidant supplementation proved to have no effect on exercise performance and related variables (gross efficiency, perceived exertion, maximal power) during exercise in the heat. Furthermore, there were no differences between the cardiovascular or thermoregulatory responses between control and antioxidant treatments. Study 2 utilized an integrative approach to investigate a classic topic in exercise physiology, namely, is the cardiac output to oxygen consumption relationship linear across a wide range of exercise intensities? The slope of the CO vs. VO2 relationship was significantly reduced from 70 to 100% of VO2max when compared to the slope from 40 to 70% of VO2max (2.0 ± 0.4 vs. 4.4 ± 0.3 l/min, p = 0.025). This finding, in combination with the plateau and eventual reduction in stroke volume at high intensity exercise compared to moderate intensity exercise (146.0 ± 16.6 vs. 138.5 ± 14.9 ml/beat, p = 0.015), argues in favor of a cardiac limitation to high intensity exercise. This study also showed that the pattern of oxygen extraction at the whole body level (arterial venous O2 difference) and the muscle level (deoxygenated hemoglobin) is not similar and that muscle specific differences exist regarding oxygen extraction. Study 3 determined that hyperthermia (elevation of skin temperature by 4.3°C and core temperature by 0.8°C) did not reduce SV independent of the increase in HR. Even under conditions of moderate hyperthermia the reduction in SV is due to the increase in HR and temporally unrelated to increases in cutaneous blood flow. In summary, antioxidant supplementation had no effect on performance, cardiovascular, or thermoregulatory responses to exercise in the heat in well trained subjects. High intensity exercise is associated with a reduced rate of increase in the CO vs. VO2 relationship. Finally, hyperthermia does not reduce SV during exercise when HR is maintained at normal levels. / text

This study directly tested implications of motivation intensity theory on effort to restrain against a behavioral urge or impulse (i.e. restraint intensity). Two factors were manipulated—magnitude of an urge and the importance of successfully resisting it—with cardiovascular (CV) responses related to active coping measured. Male and female undergraduate students were presented with a mildly- or strongly evocative film clip with instructions to refrain from showing any facial response. Success was made more or less important through coordinated manipulations of outcome expectancy, ego-involvement, and performance assessment. As expected, systolic blood pressure responses assessed during the performance period were proportional to the evocativeness of the clip when importance was high, but low regardless of evocativeness when importance was low. These findings support a new conceptual analysis concerned with the determinants and CV correlates of restraint intensity. Implications of the study and associations with current self-regulatory literature are discussed.

An oft overlooked population in research, firefighters of volunteer and paid-on-call fire departments respond to nighttime calls as a supplement to their normal working hours, making the duties taxing on the autonomic system leading to cardiovascular and endocrine disruptions. These duties also come with a tax burden on the volume and distribution of sleep. The current study was executed in order to gain valuable insight into the impact of nighttime call response in this population and the magnitude and duration of any perturbations. Eight firefighters from Greater Victoria Volunteer and Paid-on-call departments were recruited to wear Equivital EQ02 heart monitors and FitBit Charge 2 devices to record autonomic cardiovascular responses and track sleep between 1900 and 0700. HR MAX was found to significantly increase with a large effect size (p<0.0005) from 97 +/- 20 to 157 +/- 18 beats per minute in the 15 minutes preceding versus following a call within the time period. LF/HF ratios increased during the first 15-minutes following a call to 4.055 +/- 1.316 from 1.911 +/- 0.599 pre-call. HF power, RMSSD, and pNN50 all decreased significantly compared to pre-call values (796.176 +/- 414.296 ms2 vs 244.119 +/- 153.880 ms2, 51.940 +/- 7.119 ms vs 35.072 +/- 2.624 ms, 25.017 +/- 7.034% vs 7.403 +/- 2.411%). Further, all HRV measures with the exception of normalized LF and HF were found to be significantly different when waking for and attending a call versus waking on a normal day despite there being no significant differences among any variables when going to bed on nights with and without a call. Total and REM sleep were the most significantly impacted measurables of sleep. Total sleep fell to 261.11 +/- 61.11 minutes from 417.13 +/- 52.04 minutes while REM absolute and percentage of total sleep dropped from 109.88 +/- 28.47 minutes to 51.44 +/- 17.92 minutes, and 22.25 +/- 3.73% to 16.33 +/- 3.17% respectively. In response to a call, mean salivary cortisol levels increased from pre-call values by 0.426 +/- 0.202 ug/dL (p<.001). Salivary c-reactive protein levels also showed significant increases with a small effect size, though due to secretion kinetics, call response is not the likely cause. The results of this study demonstrate the presence of a significant shift in autonomic control from parasympathetic (PSNS) dominance to sympathetic control and PSNS withdrawal which evokes a cortisol-mediated stress response of comparable magnitude to literature standards for normal waking fluxes. Sleep volume, and arguably the most critical stage of sleep, rapid eye movement, are significantly impacted and the links between cognitive performance and both total and overall REM sleep indicate that call response does not just impact the cardiovascular system but may in fact be reducing mental acuity of firefighters. This is important as it has the potential to impact both self and team health and safety, not only during night time call response, but at the firefighters’ day jobs which they regularly proceed to the very same morning following a call, evidently with significant deprivation in sleep. / Graduate

Across three studies, the role that testosterone plays in how individuals respond psychologically, behaviorally, and physiologically to status challenges was investigated. Preliminary Studies 1 focused on how testosterone related to physiological and psychological responses to a medical threat. Preliminary 2 replicated the psychological effects observed in Preliminary Study 1. Study 3 examined how experimentally manipulated testosterone levels corresponded to responses to a socially judged physical endurance task across all three response types. Preliminary Study 1 examined the relationship between testosterone and conscious evaluations of and physiological reactions to a health threat. Participants were diagnosed with a fictitious enzyme deficiency before rating their views of the deficiency, as well as providing saliva samples before and after diagnosis. Basal testosterone was negatively associated with the belief that one actually had the deficiency, despite the diagnosis. Testosterone was also positively associated with a greater increase in salivary cortisol levels following the diagnosis. Self-reported anxiety was found to be positively associated with evaluating the deficiency as threatening. Preliminary Study 2 replicated the findings observed in Preliminary Study 1 regarding conscious evaluations of a medical threat. Using the same experimental manipulation, testosterone was again found to be negatively associated with ratings of the enzyme deficiency. In Preliminary Study 2, high levels of testosterone were associated with viewing the deficiency as less serious and viewing medical conditions, in general, as less threatening. Study 3 used a transdermal administration procedure to artificially elevate individuals’ testosterone levels before completing a socially evaluated task. Participants who received the testosterone administration showed greater physiological responses to the task, including cardiovascular responses and cortisol responses, compared to the placebo group. Unlike Preliminary Studies 1 and 2, Study 3 did not show any effect of testosterone on conscious evaluations of the task nor behavioral measures of performance. Taken together, the three studies highlight the different ways in which testosterone is related to responding to social threats. Testosterone appears to be associated with mobilizing physiological systems to theoretically facilitate behavioral responses to status threats. Testosterone also appears to be negatively associated with consciously evaluating certain types of threats. / text

Os núcleos da rafe são agrupamentos celulares cujo principal tipo é o serotoninérgico. Em anuros adultos a estimulação elétrica e química da rafe bulbar não causa alteração na ventilação, enquanto que em mamíferos, dependendo da localização exata desta estimulação, a ventilação pode ser inibida ou estimulada. Ainda em mamíferos, os núcleos bulbares da rafe participam da resposta cardiorrespiratória à hipóxia (5% O2) e hipercarbia (5% CO2), enquanto que em anfíbios isto ainda não foi investigado. Portanto, o objetivo do presente trabalho foi investigar a participação dos núcleos da rafe nas respostas cardiorrespiratórias à hipóxia e hipercarbia em sapos (Rhinella schneideri). Para isso, primeiramente os núcleos da rafe foram localizados e identificados na espécie estudada. Imunorreatividade para proteínas Fosrelacionadas foi utilizada para verificar se estes núcleos são ativados ou inibidos durante o estímulo hipóxico e hipercárbico, e, adicionalmente, o papel dos núcleos magno e pontino da rafe nas respostas cardiorrespiratórias à hipóxia e hipercarbia foi investigado por meio da lesão nãoseletiva com ácido ibotênico. A ventilação pulmonar foi medida diretamente pelo método pneumotacográfico e a pressão arterial por canulação da artéria femoral. Os resultados demonstram que os núcleos bulbares da rafe são inibidos após o estímulo hipóxico e hipercárbico. A hipóxia causou aumento da ventilação pulmonar e da frequência cardíaca nos grupos veículo e lesado. A hipercarbia causou aumento da ventilação pulmonar em ambos os grupos. A lesão nãoseletiva dos núcleos magno e pontino da rafe não teve efeito na ventilação basal (durante normóxia normocárbica) e nas respostas cardiorrespiratórias à hipóxia e hipercarbia, sugerindo que estes núcleos não participam do controle da ventilação em condições basais ou durante a hipóxia e hipercarbia em sapos. / The raphe nuclei are brainstem cell groups and the main cell type is serotonergic. In adult anurans electrical or chemical stimulation of the medullary raphe has no effect on ventilation, whereas in mammals depending on the specific site of stimulation, an excitatory or inhibitory response is elicited. In mammals the medullary raphe participate in the ventilatory and cardiovascular response to hypoxia and hipercarbia while in amphibians there are no data available. Thus the present study was designed to investigate whether the raphe nuclei of toads (Rhinella schneideri) participate in the ventilatory and cardiovascular response to hypoxia (5% O2) and hipercarbia (5% CO2). First the raphe nuclei were located and identified. Fosrelated immunoreactivity was used to verify whether the raphe nuclei are activated or inhibited by hypoxia or hypercarbia. In addition, the role of raphe magnus and pontis in the respiratory and cardiovascular responses to hypoxia and hypercarbia were investigated by nonselective lesioning with ibotenic acid. Pulmonary ventilation was directly measured by pneumotachographic method and the arterial pressure by a femoral catheter. The results indicate that the medullary raphe nuclei are inhibited after hypoxic and hypercarbic stimulus (2,5h). Hypoxia caused hyperventilation and increase in the cardiac frequency in the vehicle and lesioned groups. Hypercarbia caused hyperventilation in both groups. Chemical lesions in the raphe magnus and pontis did not affect ventilatory or cardiovascular variables under resting conditions (normoxic normocárbica) or during the response to hypoxia or hipercarbia.

Os núcleos da rafe são agrupamentos celulares cujo principal tipo é o serotoninérgico. Em anuros adultos a estimulação elétrica e química da rafe bulbar não causa alteração na ventilação, enquanto que em mamíferos, dependendo da localização exata desta estimulação, a ventilação pode ser inibida ou estimulada. Ainda em mamíferos, os núcleos bulbares da rafe participam da resposta cardiorrespiratória à hipóxia (5% O2) e hipercarbia (5% CO2), enquanto que em anfíbios isto ainda não foi investigado. Portanto, o objetivo do presente trabalho foi investigar a participação dos núcleos da rafe nas respostas cardiorrespiratórias à hipóxia e hipercarbia em sapos (Rhinella schneideri). Para isso, primeiramente os núcleos da rafe foram localizados e identificados na espécie estudada. Imunorreatividade para proteínas Fosrelacionadas foi utilizada para verificar se estes núcleos são ativados ou inibidos durante o estímulo hipóxico e hipercárbico, e, adicionalmente, o papel dos núcleos magno e pontino da rafe nas respostas cardiorrespiratórias à hipóxia e hipercarbia foi investigado por meio da lesão nãoseletiva com ácido ibotênico. A ventilação pulmonar foi medida diretamente pelo método pneumotacográfico e a pressão arterial por canulação da artéria femoral. Os resultados demonstram que os núcleos bulbares da rafe são inibidos após o estímulo hipóxico e hipercárbico. A hipóxia causou aumento da ventilação pulmonar e da frequência cardíaca nos grupos veículo e lesado. A hipercarbia causou aumento da ventilação pulmonar em ambos os grupos. A lesão nãoseletiva dos núcleos magno e pontino da rafe não teve efeito na ventilação basal (durante normóxia normocárbica) e nas respostas cardiorrespiratórias à hipóxia e hipercarbia, sugerindo que estes núcleos não participam do controle da ventilação em condições basais ou durante a hipóxia e hipercarbia em sapos. / The raphe nuclei are brainstem cell groups and the main cell type is serotonergic. In adult anurans electrical or chemical stimulation of the medullary raphe has no effect on ventilation, whereas in mammals depending on the specific site of stimulation, an excitatory or inhibitory response is elicited. In mammals the medullary raphe participate in the ventilatory and cardiovascular response to hypoxia and hipercarbia while in amphibians there are no data available. Thus the present study was designed to investigate whether the raphe nuclei of toads (Rhinella schneideri) participate in the ventilatory and cardiovascular response to hypoxia (5% O2) and hipercarbia (5% CO2). First the raphe nuclei were located and identified. Fosrelated immunoreactivity was used to verify whether the raphe nuclei are activated or inhibited by hypoxia or hypercarbia. In addition, the role of raphe magnus and pontis in the respiratory and cardiovascular responses to hypoxia and hypercarbia were investigated by nonselective lesioning with ibotenic acid. Pulmonary ventilation was directly measured by pneumotachographic method and the arterial pressure by a femoral catheter. The results indicate that the medullary raphe nuclei are inhibited after hypoxic and hypercarbic stimulus (2,5h). Hypoxia caused hyperventilation and increase in the cardiac frequency in the vehicle and lesioned groups. Hypercarbia caused hyperventilation in both groups. Chemical lesions in the raphe magnus and pontis did not affect ventilatory or cardiovascular variables under resting conditions (normoxic normocárbica) or during the response to hypoxia or hipercarbia.

Agtarap, Wright, Mlynski, Hammad, and Blackledge took an initial step in providing support for the predictive validity of a new conceptual analysis concerned with behavioral restraint, defined as active resistance against a behavioral impulse or urge. The current study was designed to partially replicate and extend findings from their study, employing a common film protocol and a procedure for inducing low- and high levels of fatigue. Analyses on key data indicated that the fatigue manipulation was ineffective. On the other hand, they supported the suggestion that behavioral restraint should be proportional to the strength of an urge being resisted so long as success is perceived as possible and worthwhile. Analyses also provided evidence of gender differences for this behavioral restraint task. Women showed relatively enhanced CV responses to my manipulation of urge magnitude, performed less well, rated the behavioral restraint challenge as harder, and rated success on the more difficult behavioral restraint task as more important. A broad indication is that men and women can differ in the strength of impulses they experience in response to stimulus presentations as well as in the importance they place on resisting the impulses.

PURPOSE: Hypertension (HTN) affects one in every three adults in the United States. Often associated with the older population, this silent killer has emerged in an unsuspecting group, young military soldiers. With the rapid succession of multiple deployments, long intervals between blood pressure (BP) assessments, and the absence of cardiovascular (CV) measures during the pre and post deployment health screenings; soldiers may be at higher risk for HTN than their civilian counterparts of the same age. The purpose of this study was to explore real-time continuous CV measures of soldiers before, during, and after exposure to a simulated combat stressor as well as to assess which personal characteristics played a significant role. METHODS: Applying the Allostasis/Allostatic Load theoretical framework, a repeated measure quasi-experimental design was used to compare the CV measures of two groups: one exposed to a physical combat stressor (experimental) and the other exposed to a psychological combat stressor (control). A convenience sample of 60 college Army Reserve Officer Training Corps cadets were fitted with Tiba Medical Ambulo 2400 ambulatory BP monitors for 48 continuous hours. Several CV indices were analyzed using one-way Analysis of Variance (ANOVA), paired t-test, and independent sample t-test. Four instruments (Participant Information Sheet, State-Trait Anxiety Inventory, Paintball Perceived Stress Questionnaire, and Army Physical Fitness Test) were used to assess which characteristics played the most significant role in the CV response. RESULTS: Demographic characteristics between the two 30-cadet groups were not statistically different, with the exception of deployment history (experimental = 4, control= 0). Hours after the stress exposure, subjects in the experimental group had a higher mean awake systolic blood pressure (SBP) when compared to the control group (113.76 mm Hg vs 102.98 mm Hg, p= 009). When assessing pre and post stressor morning BP surge and evening BP decline, the control group showed the biggest change. Significant bivariate correlations (p > .05) found that: Females consistently had higher pulse rates (PR) throughout each of the phases. Age positively correlated with elevated BP during the stressor, and increased morning BP surge post stressor. African Americans had higher sleep BPs pre stressor, and decreased SBP recovery post stressor; Hispanics had higher PRs during and after the stressor. Waist circumference positively correlated with elevated BP morning surge pre stressor but, body mass index (BMI) positively correlated with elevated BP morning surge post stressor as well as elevated BP during the stressor. Family history of HTN played no significant role; however, deployment history correlated with mean awake SBP post stressor. Trait anxiety scores negatively correlated with SBP recovery while state anxiety scores positively correlated with post stressor awake mean arterial pressure and evening SPB decline. Perceived stress during the stressor negatively correlated with post stressor SBP morning surge with females reporting higher anxiety and stress. Finally, Army Physical Fitness (APFT) total scores as well as APFT run scores negatively correlated with pre and post stressor sleep PRs. DISCUSSION/IMPLICATIONS: Age, female gender, African American descent, Hispanic ethnicity, waist circumference, BMI, previous deployment history, level of fitness and the psychological stress state during and after a stressor played significant roles in soldiers' CV response. SBP was the most dynamic and informative of the CV indices and a psychological stressor was comparable to a physical stressor when observing the residual effect of stress. If a combat exercise was enough of a stressor to produce residual CV effects that lasted well into following morning, the residual effect of a lengthy strenuous deployment may be alarming. This study not only provided a snapshot of the CV health of incoming young soldiers, but also provided evidence to support policy change regarding the implementation of regular CV health assessments before and after deployment.