Higher Stress Response Research Articles

Emotion-oriented coping styles are Associated with higher stress response and lower quality of life in patients with Schizophrenia

Emotion-oriented coping styles are Associated with higher stress response and lower quality of life in patients with Schizophrenia

Study on mechanical response control of metal-ceramic dual phase hybrid lattice structure

Different from the previous trial-and-error and empirical development process of new materials, the failure and deformation of meso-structure of lattice structures are considered as a means to customize the mechanical response in this paper. Based on this, we propose a novel metal-ceramic dual-phase hybrid lattice structure (DPHLS) that exhibits both high peak stress and a prolonged plateau stage in its mechanical response. This design aims to meet the complex mechanical response requirements of impact target materials in hard target penetration research. The DPHLS is composed of a ceramic-based SC plate lattice structure and a metal-based FCC plate lattice structure, allowing for a broad range of mechanical properties control. Besides, by combining the advantages of both ceramic and metal, the DPHLS exhibits seemingly conflicting properties of load-bearing capacity and energy absorption. In the present work, the contribution of failure and deformation behavior to the mechanical response of the structure is deeply analyzed at the mesoscopic level using theoretical analysis and numerical simulation. The quantitative relationship between the geometrical parameters of the structure and the mechanical response is established actively. The results show that the three dimensionless geometric parameters, which characterize the geometry of DPHLS, can effectively regulate its mechanical response. This study not only provides a reliable theoretical basis for the design of mesostructures in DPHLS, but also proposes a novel strategy for the customization of mechanical response.

HES1 potentiates high salt stress response as an enhancer of NFAT5-DNA binding

High salt conditions and subsequent hyperosmolarity are injurious cellular stresses that can activate immune signaling. Nuclear factor of activated T-cells 5 (NFAT5) is an essential transcription factor that induces osmoprotective genes such as aldose reductase (AR) and betaine-GABA transporter 1 (BGT1). High salt stress-mediated NFAT5 activation is also reported to accelerate the inflammatory response and autoimmune diseases. However, the systemic regulation of NFAT5 remains unclear. Here, we performed a genome-wide siRNA screen to comprehensively identify the regulators of NFAT5. We monitored NFAT5 nuclear translocation and identified one of the Notch signaling effectors, Hairy and enhancer of split-1 (HES1), as a positive regulator of NFAT5. HES1 was induced by high salinity via ERK signaling and facilitated NFAT5 recruitment to its target promoter region, resulting in the proper induction of osmoprotective genes and cytoprotection under high salt stress. These findings suggest that, though HES1 is well known as a transcriptional repressor, it positively regulates NFAT5-dependent transcription in the context of a high salinity/hyperosmotic response.

IBS stress reactivity phenotype is associated with blood transcriptome profiles and microstructural and functional brain changes.

Clinical evidence suggests significant interindividual differences in stress reactivity (SR), but biological mechanisms and therapeutic implications of these differences are poorly understood. We aimed to identify the biological basis of increased SR by investigating associations between a psychometric-based phenotype with blood transcriptomics profiles of increased sympathetic nervous system (SNS) activation and brain imaging phenotypes in irritable bowel syndrome (IBS) participants and healthy controls (HCs). A cross-sectional observational study design, transcriptomics profiling, multimodal brain imaging, and psychosocial assessments were obtained in 291 female and male IBS participants and HCs. Prior to analyses, unsupervised clustering was applied to derive high and low SR subgroups across participants based on two measures of SR. General linear models tested for SR group differences in clinical and biological parameters. Exploratory analyses examined associations between SR group-specific brain alterations and gene expression. The high, compared to low SR group showed greater cyclic AMP response element-binding protein (CREB) gene expression consistent with tonic SNS activity and proinflammatory changes in whole blood. Brain imaging showed neuroplastic changes in the high SR group consistent with an upregulation of ascending arousal systems and sensory processing and integration regions, and functional connectivity changes in the central autonomic network. SR moderated the sex difference in extraintestinal symptoms. The findings support a model of tonically increased SNS activity as a plausible risk factor for increased autonomic reactivity to psychosocial stressors and low grade immune activation in both IBS and HCs, with a greater prevalence in IBS. These findings may have important implications for personalized treatment interventions in IBS.

Too little, too much, and "just right": Exploring the "goldilocks zone" of daily stress reactivity.

Hormetic models of stress resilience describe nonlinear relations for exposure to adversity and health outcomes, where exposure induces salutary changes up to a threshold, with changes becoming deleterious afterward. Here we apply a hormetic model of stress to reactivity to daily stressors, examining whether mental and physical health benefits arise from low-to-moderate reactivity but then decrease at higher levels. Data are from the second wave of the National Study of Daily Experiences (NSDE). Adults (N = 2,022; Mage = 58.61, SD = 12.12, age range: 35-86; 57% female) completed telephone interviews detailing their stressors and affect on eight consecutive evenings. A series of multilevel structural equation models estimated within-person associations between daily stressors and negative affect (i.e., stress reactivity), and between-person linear and quadratic effects of stress reactivity on mental and physical health outcomes (i.e., life satisfaction, psychological distress, and number of chronic conditions). Findings reveal a significant quadratic effect for each outcome, indicating a U-shaped pattern (inverse U for positively valenced life satisfaction), such that low and high levels of stress reactivity were associated with poorer health and well-being, whereas moderate levels of daily stress reactivity predicted better health outcomes. These findings suggest that individuals who display either very low- or very high-stress reactivity may benefit from interventions that target their emotion regulation skills and coping resources. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Photosynthetic response to a winter heatwave in leading and trailing edge populations of the intertidal red alga Corallina officinalis (Rhodophyta)

Marine heatwaves (MHWs) caused by anthropogenic climate change are becoming a key driver of change at the ecosystem level. Thermal conditions experienced by marine organisms across their distribution, particularly towards the equator, are likely to approach their physiological limits, resulting in extensive mortality and subsequent changes at the population level. Populations at the margins of their species’ distribution are thought to be more sensitive to climate-induced environmental pressures than central populations, but our understanding of variability in fitness-related physiological traits in trailing versus leading-edge populations is limited. In a laboratory simulation study, we tested whether two leading (Iceland) and two trailing (Spain) peripheral populations of the intertidal macroalga Corallina officinalis display different levels of maximum potential quantum efficiency (Fv/Fm) resilience to current and future winter MHWs scenarios. Our study revealed that ongoing and future local winter MHWs will not negatively affect leading-edge populations of C. officinalis, which exhibited stable photosynthetic efficiency throughout the study. Trailing edge populations showed a positive though non-significant trend in photosynthetic efficiency throughout winter MHWs exposure. Poleward and equatorward populations did not produce significantly different results, with winter MHWs having no negative affect on Fv/Fm of either population. Additionally, we found no long-term regional or population-level influence of a winter MHWs on this species’ photosynthetic efficiency. Thus, we found no statistically significant difference in thermal stress responses between leading and trailing populations. Nonetheless, C. officinalis showed a trend towards higher stress responses in southern than northern populations. Because responses rest on a variety of local population traits, they are difficult to predict based solely on thermal pressures.

Paired metabolomics and volatilomics provides insight into transient high light stress response mechanisms of the coral Montipora mollis

The coral holobiont is underpinned by complex metabolic exchanges between different symbiotic partners, which are impacted by environmental stressors. The chemical diversity of the compounds produced by the holobiont is high and includes primary and secondary metabolites, as well as volatiles. However, metabolites and volatiles have only been characterised in isolation so far. Here, we applied a paired metabolomic-volatilomic approach to characterise holistically the chemical response of the holobiont under stress. Montipora mollis fragments were subjected to high-light stress (8-fold higher than the controls) for 30 min. Photosystem II (PSII) photochemical efficiency values were 7-fold higher in control versus treatment corals immediately following high-light exposure, but returned to pre-stress levels after 30 min of recovery. Under high-light stress, we identified an increase in carbohydrates (> 5-fold increase in arabinose and fructose) and saturated fatty acids (7-fold increase in myristic and oleic acid), together with a decrease in fatty acid derivatives in both metabolites and volatiles (e.g., 80% decrease in oleamide and nonanal), and other antioxidants (~ 85% decrease in sorbitol and galactitol). These changes suggest short-term light stress induces oxidative stress. Correlation analysis between volatiles and metabolites identified positive links between sorbitol, galactitol, six other metabolites and 11 volatiles, with four of these compounds previously identified as antioxidants. This suggests that these 19 compounds may be related and share similar functions. Taken together, our findings demonstrate how paired metabolomics-volatilomics may illuminate broader metabolic shifts occurring under stress and identify linkages between uncharacterised compounds to putatively determine their functions.

Phosphatidylserine Counteracts the High Stocking Density-Induced Stress Response, Redox Imbalance and Immunosuppression in Fish Megalobrama ambylsephala.

This study was conducted to investigate the effects of dietary phosphatidylserine (PS) supplementation on the growth performance, stress response, non-specific immunity and antioxidant capacity of juvenile blunt snout bream (Megalobrama ambylcephala) cultured under a high stocking density. A 2 × 2 two-factorial design was adopted, including two stocking densities (10 and 20 fish/m3) and two dietary PS levels (0 and 50 mg/kg). After the 12-week feeding trial, the high stocking density significantly decreased the final weight; weight gain rate; specific growth rate; feed intake; nitrogen retention efficiency; plasma complement 3 (C3) level; albumin/globulin (ALB/GLB, A/G) ratio; activity of myeloperoxidase, lysozyme (LZM) and glutathione peroxidase (GPX); gpx transcription; and abundance of sirtuin3 (Sirt3) and nuclear factor erythroid-2-related factor 2 (Nrf2). However, it significantly increased the plasma levels of cortisol, glucose (GLU), lactic acid (LD), total protein and GLB; hepatic malondialdehyde (MDA) content; and sirt1 transcription. PS supplementation significantly increased the plasma ALB and C4 levels; the A/G ratio; the activity of LZM, CAT and GPX; the transcription of sirt1, nrf2, manganese-containing superoxide dismutase and catalase; and the Nrf2 abundance. However, it significantly decreased the plasma levels of cortisol, GLU and GLB, as well as the hepatic MDA content. In addition, there was a significant interaction between the stocking density and PS supplementation regarding the effects on the plasma LD, ALB, GLB and C3 levels; A/G ratio; hepatic CAT activity; and protein abundance of Sod2. In conclusion, PS supplementation can counteract the high stocking density-induced stress response, redox imbalance and immunosuppression in blunt snout bream.

Influences of sleep, cortisol reactivity, and risk/reward-based decision-making on suicide

Background and objectivesPoor sleep quality is a known contributor to suicidal thoughts and behaviors. This study examines whether sleep quality modulates the effect of an individual's stress response and risk/reward-based decision making on suicide risk. MethodsParticipants were 160 adults at a residential substance use treatment facility with lifetime exposure to trauma who completed a clinician-administered measure of suicide risk, the Iowa Gambling Task (IGT), and a self-report measure of sleep. Cortisol reactivity (i.e., changes in cortisol before and after a personalized trauma script) was used to measure stress response. We used quantile regression to examine the effects of sleep, cortisol, and risk/reward decision-making on suicide risk. ResultsWe found poor sleep quality to be increasingly salient in individuals at greater risk for suicide than those at lower risk for suicide. Furthermore, individuals with moderate to moderate-high levels of suicide risk seem to have greater cortisol reactivity. In the low-moderate quantile, we found suicide risk to be associated with both high stress reactivity and low-risk, high-reward decision-making, as well as low stress reactivity and high-risk/low-reward decision-making. LimitationsThese findings should be interpreted considering several methodological constraints, such as the use of a pre-determined sample and instruments not tailored for our hypotheses, the MINI ‘Suicide’ Module's limited differentiation between suicidal ideation and behavior, and variably timed cortisol sampling. ConclusionsDespite these limitations, the findings from this study support the use of evidence-based interventions focused on improving sleep quality and managing emotional reactivity to decrease suicide risk.

During exposure to 3%, 5%, and 7% CO2, both Behaviorally Inhibited and Non-Behaviorally Inhibited individuals increased minute ventilation through different mechanisms

Behavioral inhibition (BI) is a temperament associated with increased vulnerability to stress compared to their non-behaviorally inhibited (NBI) counterparts. Previous studies have demonstrated that BI individuals have a higher stress response than NBI individuals, suggesting that BI individuals have significantly less parasympathetic nervous system output at rest. However, this study only compared room air to 7% carbon dioxide (CO2) concentrations. The difference in the sympathetic nervous system activation between BI and NBI individuals under constant increasing stress is still unknown. Our current study tested the hypothesis that BI individuals will have an increased stress response as the inhaled CO2 concentration increases. In humans, we tested the effect of increasing CO2 concentrations on tidal volume, breathing rate, heart rate, and blood pressure. BI individuals were identified through self-reported questionnaires, such as The Adult Measure of Behavioral Inhibition (AMBI). A 15-minute control period of room air breathing was completed followed by 5 minutes each of 3% and 5% inspired CO2, and 3 minutes of 7% inspired CO2. Preliminary results indicate that BI individuals breathe differently at a physiological level and differ in their stress response. Thank you to Carthage College's Student Travel Grant as well as the Neuroscience and Biology department for supporting this research. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Glucocorticoid receptors regulate hypothalamic CRH neuron activity in primary hypertension

The hypothalamic-pituitary-adrenal axis is important in maintaining homeostasis in response to physical and psychological stressors. The corticotropin-releasing hormone (CRH) is a neuropeptide synthesized by CRH neurons in brain regions including paraventricular nucleus (PVN) of the hypothalamus. The glucocorticoids synthesized and released in adrenal gland act on hypothalamic CRH-expressing neurons inhibit the CRH production and maintain the level of glucocorticoids. The glucocorticoid receptor (GR) is critical for this negative feedback to regulate CRH synthesis and release. Hypertension is associated with high stress response and CRH mRNA levels. The number of CRH-expression neurons are significantly increased in PVN of the hypothalamus in primary hypertension patients. this study determined if the HPA axis negative feedback is altered and contribute to maintaining hypertension. We measured mRNA expression levels of GRs and MR in PVN tissue obtained from adult Wistar-Kyoto normotensive rats (WKYs) and spontaneously hypertensive rats (SHRs) and found that the GR mRNA expression level was significantly lower in SHRs that in WKY rats, while the MR gene expression did not differ between WKY rats and SHRs. Furthermore, we found that acute perfusion of dexamethasone (DEX), a synthetic glucocorticoid, significantly decreased frequency of spontaneous excitatory postsynaptic synaptic currents (EPSCs) in identified PVN-CRH expressing neurons in brain slices prepared from WKY and SHRs. DEX caused a greater reduction of frequency of EPSCs in SHRs was than in WKY rats. Acute perfusion of DEX significantly increased the firing rate of PVN-CRH neurons in WKY rats but did not change the firing rate in SHRs. In addition, incubation of brain slices with DEX for 1 hr significantly inhibited the firing activity of PVN-CRH neurons in WKY rats but did not change the firing activity of PVN CRH neurons in SHRs. These data suggested that the glucocorticoid excites PVN-CRH neurons in acute phase while inhibits these neurons in chronic phase in normotensive rat. In hypertension, downregulated GR may be responsible for impaired the HPA axis feedback and contribute to hypertension. HL139523, HL142133, and HL159157. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Metabolomic reveals the responses of sludge properties and microbial communities to high nitrite stress in denitrifying phosphorus removal systems

Nitrite, as an electron acceptor, plays a good role in denitrifying phosphorus removal (DPR); however, high nitrite concentration has adverse affects on sludge performance. We investigated the precise mechanisms of responses of sludge to high nitrite stress, including surface characteristics, intracellular and extracellular components, microbial and metabolic responses. When the nitrite stress reached 90 mg/L, the sludge settling performance was improved, but the activated sludge was aging. FTIR and XPS analysis revealed a significant increase in the hydrophobicity of the sludge, resulting in improve settling performance. However, the intracellular carbon sources synthesis was inhibited. In addition, the components in the tightly bound extracellular polymeric substances (TB-EPS) of sludge were significantly reduced and indicated the disturb of metabolism. Notably, Exiguobacterium emerged as a new genus when face high nitrite stress that could maintaining survival in hostile environments. Moreover, metabolomic analysis demonstrated strong biological response to nitrite stress further supported above results that include the inhibited of carbohydrate and amino acid metabolism. More importantly, some lipids (PS, PA, LysoPA, LysoPC and LysoPE) were significantly upregulated that related enhanced membrane lipid remodeling. The comprehensive analyses provide novel insights into the high nitrite stress responses mechanisms in activated sludge systems.

Effects of lifestyle factors on job-related stress and stress responses in police officers in Japan

Abstract Objective The aim of this study was to investigate the relationship between stress responses and lifestyle factors of police officers in Japan. Methods This study used a cross-sectional design. Of indivudals who underwent legally required health screenings in a Prefectural Police, 9633 men and 1086 women completed the Brief Job Stress Questionnaire. Then a multivariate analysis for various lifestyle factors was performed with high stress and six stress responses (low vitality, high irritability, high fatigue, high anxiety, substantial depressive feeling, and high somatic symptoms) as dependent variables. Results Of the potential covariates, short sleep duration consistently related to various stress and stress responses. The odds ratios of short sleep duration were consistently significant for high stress in men and women, for high irritability in men, for high fatigue in women, for high depressive feeling in men and women, and for high somatic symptoms in men and women. As for factors other than sleep duration, age, rank, marital status, overtime work, and rhythm of daily life were significantly associated with high stress and various stress responses. Conclusions The results of this study consistently showed that short sleep duration increases the risk of high stress and stress responses. Overall, more women than men in the police force reported short sleep duration, which may be due to work–family conflicts. Maintaining adequate sleep duration quality would reinforce preventive measures to avoid aggravation of stress status.

Associations between Difficulty in Accessing Maternal and Child Health Services and Stress Responses among Mothers Raising Young Children during the COVID-19 Pandemic in Japan.

In Japan, maternal and child health (MCH) services were canceled or limited during the COVID-19 pandemic, potentially damaging the mental health of mothers raising young children. This study aimed to examine associations between difficulty in accessing MCH services and various stress responses among such mothers in Japan. An Internet-based questionnaire survey was conducted in November 2022 targeting mothers raising young children who had registered with a Japanese online research company (n = 1032). The questionnaires included items from the Public Health Research Foundation Stress Checklist (Short Form) (PHRF-SCL(SF)), sociodemographic variables, and questions about difficulty accessing MCH services due to COVID-19. Chi-squared tests and multivariate logistic regression analysis were performed. In total, 45.7% of mothers experienced difficulty in accessing MCH services due to COVID-19. Mean PHRF-SCL(SF) scores were 4.9 for anxiety, 7.3 for tiredness, 2.8 for autonomic symptoms, and 5.2 for depression. These scores indicated worse stress responses than the general population and mothers raising young children before the COVID-19 pandemic. Mothers who experienced difficulty in accessing MCH services due to COVID-19 were 1.47-1.53 times more likely to be associated with high stress responses (PHRF-SCL(SF) scores). Given the difficulty mothers faced accessing MCH services due to COVID-19 and the negative impact this had, careful follow-up and support are necessary for mothers affected by the COVID-19 pandemic.

Potential synergistic regulation of hsp70 and antioxidant enzyme genes in Pyropia yezoensis under high temperature stress

High temperatures have been regarded as one of the main factors limiting Pyropia yezoensis cultivation in recent years. Both the heat shock proteins and antioxidant enzymes genes were activated timely before heat damage to the cell. Here, the activities of different antioxidant enzymes under different conditions, including HSF inhibitor, CaM inhibitor, and HSP70 protein inhibitor were determined. Then, RNA-seq was performed using samples that had been pretreated with corresponding chemicals under high temperature conditions. The principal component analysis inferred that the shift of gene transcription patterns under high temperature conditions was closely related to HSF since the addition of QR suppressed the changes in gene transcription pattern. The hsp70 genes and antioxidant enzyme genes were categorized into three groups by the method of WGCNA. And the HSE sites were identified using plantPAN and FIMO in most genes of the categories showed relationship to HSF. Quantitative RT-PCR analysis of designated genes (FMPK >10) indicated that the expression of hsp70 and antioxidant enzyme genes in Py. yezoensis showed various transcriptional patterns, including upregulation, downregulation, and no significant changes in response to high temperature stress. The classification between qRT-PCR and WGCNA results showed a certain consistency. Considered the results above together, it was speculated that there were different HSFs regulated the expression of different genes of hsp70 and antioxidant enzymes, and HSP70 might also regulate the expression of anti-oxidase genes under the conditions of long-term stress. Additionally, transcription factors other than HSF might be involved in the high temperature stress response. The results indicated the complexity of heat stress response mechanisms in Py. yezoensis.

Association between support of basic psychological needs and stress response as mediated by motivation for solitude.

This study examined the relationship between not self-determined / self-determined solitude and stress responses, as well as the effect of supporting / thwarting of basic psychological needs. The sample consisted of 606 Japanese people aged 20 years and older. We used a cross-sectional survey to measure their motivations for solitude, supporting / thwarting of basic psychological needs, and stress responses. Not self-determined solitude was negatively correlated with supporting of basic psychological needs and positively correlated with thwarting of basic psychological needs. In addition, a cutoff score of 16 for not self-determined solitude was found to be optimal for identifying individuals with a high stress response. Mediation analysis revealed that supporting / thwarting of basic psychological needs has direct effects on stress responses and indirect effects mediated by not self-determined solitude. These findings suggest that fostering environments that support basic psychological needs of autonomy, competence, and relatedness can alleviate not self-determined solitude and reduce stress responses.

The effect of pectointercostal fascial block on stress response in open heart surgery.

Activation of the hypothalamus-pituitary-adrenal (HPA) axis and inflammatory processes are common forms of stress response. The increased stress response is associated with a higher chance of complications. Open hearth surgery is one of the procedures with a high-stress response. Pectointercostal fascial block (PIFB), as a new pain management option in sternotomy, has the potential to modulate the stress response. To determine the effect of PIFB on stress response in open heart surgery. This study was a Randomized Controlled Trial on 40 open heart surgery. Patients were divided into two groups, control (20 patients) and PIFB (20 patients). Primary parameters included basal and postoperative TNF-α, basal and post sternotomy ACTH, and basal, 0, and 24 hours postoperative NLR. Secondary parameters include the amount of opioid use, length of the post-operative ventilator, length of ICU stay, and Numeric Rating Scale (NRS) 6, 12, 24, and 48 hours postoperative. The PIFB group had a decrease in ACTH levels with an average change that was not significantly different from the control group (-57.71 ± 68.03 vs. -129.78 ± 140.98). The PIFB group had an average change in TNFα levels and an average increase in NLR 0 hours postoperative that was not significantly lower than the control group (TNFα: -0.52 ± 1.31 vs. 0.54 ± 1.76; NLR: 12.80 ± 3.51 vs. 14.82 ± 4.23). PIFB significantly reduced the amount of opioid use during surgery, NRS at 6, 12, and 24 hours, and the length of post-operative ventilator use (P < 0.05, CI: 95%). PIFB has a good role in reducing the stress response of open heart surgery and producing good clinical outcomes.

Enhanced recovery after adolescent idiopathic scoliosis surgery care pathway: Perioperative strategy to improve outcome

IntroAIS surgery generates a high inflammatory stress response which might influence the outcome in the perioperative period. Enhanced Recovery After Surgery (ERAS) is a global multidisciplinary care pathway aimed to improve patient's recovery. Research questionThe purpose of this article is to expose our actual ERAS protocol for AIS surgery and compare it with the earlier non ERAS management in our institution.Our primary outcome focus on the re-hospitalisation and complications rates at 30 and 90 days postoperatively. Our secondary outcomes focus on the overall morphine consumption, pain scores and side effects during the hospitalisation. MaterialWe compare the results of the ERAS group (2019–2022) with the previous existing classical care pathway (2017–2019). The data were collected in our standard medical files. ResultsOur ERAS care pathway for AIS surgery lead to consequently improve the outcome regarding the VAS scores, the morphine consumption, the LOS and the complication and re hospitalisation rates. DiscussionRegarding our results, ERAS care pathway for AIS surgery appears to be efficient in terms of benefits on complications rates, LOS and opioid consumption.Intrathecal morphine and “anti-inflammatory” anaesthesia provides a good quality of pain management and allows the patient to get up early.A superiority trial might be interesting to highlight the role of the ERAS pathway in AIS surgery.

Evaluation of neurologic testing in guinea pigs (Cavia porcellus)

BackgroundUp-to-date, specialized literature provides very little information on performing and interpreting clinical neurological tests on small mammals, particularly guinea pigs. MethodsTwo clinical neurologists performed separate neurological examinations of 25 guinea pigs. The structure of the examination was similar to those performed in other companion animals and included hands-off examination, postural reaction tests, cranial nerve tests, and spinal reflex tests. Each test was evaluated for feasibility, reproducibility, and associated stress level for the animals. ResultsThe following tests revealed an excellent ability to elicit the expected response: hopping reaction in the thoracic limbs, wheelbarrowing and hemiwalking, medial and lateral palpebral reflex, auricular sensitivity, maxillary sensitivity, horizontal oculocephalic reflex, tone of the jaw, voluntary movement of the tongue, and direct pupillary light reflex. On the other hand, a poor ability to elicit the expected response was observed in the following tests: visual paw replacement of the thoracic limbs, tactile paw replacement in both thoracic and pelvic limbs, paper test for thoracic and pelvic limbs, mandibular sensitivity, vertical oculocephalic reflex, menace response, patellar reflex, cutaneous trunci reflex, and perineal reflex. The most reliable spinal reflex test with a good ability to elicit the expected response was the withdrawal reflex for both thoracic and pelvic limbs. The guinea pigs experienced the most stress during the spinal reflex tests. ConclusionIt is possible to apply several clinical neurological tests on guinea pigs and produce meaningful results. However, certain tests elicited high stress responses in the animals and should therefore only be used if necessary. Based on the results, we propose a possible protocol for neurological examination in guinea pigs. Clinical relevanceThis is the first study to evaluate a full range of clinical neurological tests performed on guinea pigs. The results of this study could lead to a better understanding of lesion localization and serve as a basis for further diagnostic and therapies in guinea pigs with neurological diseases.

P134: Immediate stress responses to music during psychomotor stimulation in 2 study cases with dementia.

Background:The use of music in older people with advanced dementia is possible because perception, sensitivity, emotion, and memory of music may remain intact after other types of memory disappear. Previous literature is controversial about stress biomarkers response to music introduction in therapy routines for people with severe cognitive impairment and neural-behavioural disorders. Particularly, for these patients, it is possible that they feel lower pleasure levels with music-based therapies.Objective:To characterize the immediate physiological effects of listening to music during psychomotor stimulation in an old participant with combined dementia and depression disorder and in a participant with a dementia diagnosis.Methods:Two study cases with dementia diagnosis participated in this study (P1: 84yrs; male Parkinson; FAB=9; P2: 85 yrs; female; Alzheimer; FAB=11; depression diagnosis) and were submitted to psychomotor stimulation (2 sessions). The first 20 min. of each session was dedicated to psychomotor stimulation without music (A), followed by 20 minutes with music (B). Heart rate was monitored (H10 Polar sensor) in a continuous mode. Cortisol levels were collected at the beginning of the session (T0) and then repeated at periods A and B (μg/dL). The range between minimum and maximum HR values (beats per minute- bpm) and mean values for cortisol levels were considered for the stress response analysis.Results:Salivary cortisol levels were higher at T0 for P1 (0.393 vs 0.203). During period A, the P1 slightly decreased their values (↓0,076) and P2 had no changes. After introducing music, both P1 and P2 increased cortisol levels (↑0,085; 0,162↑). For both P1 and P2, a wide range of HR was detected during period B (P1: 13 vs 23 bpm) vs (P2: 15 vs 41 bpm).Conclusion:Immediate responses to the music inclusion in a psychomotor intervention caused an augmented stress response in elderly participants with dementia, especially in P2. In specific, the depression diagnosis in this participant may be associated with a low capacity to handle emotions during new experiences, causing a higher stress response.