repeated exposure
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2022 ◽  
pp. 543-551
Author(s):  
Avishai Antonovsky

AbstractIn this chapter, the author addresses salutogenesis and the mental health of first responders (FRs). Research has observed FRs to be prone to psychological distress and psychopathology resulting from their repeated exposure to potentially traumatic events. Most of the literature is focused on postevent treatment. The author discusses a mental fitness model that includes salutogenically oriented psychoeducation and other activities to enhance mental fitness among FRs and build their psychological strengths as they face adversities on their job.In closing, the author recommends that besides psychopathology-oriented programs intended for providing mental first aid to FRs and for the communities who experience potentially traumatic events, intervention also should include salutogenically based mental preparation programs. These should emphasize the strengths and resources that could help FRs arrive at scenes of disaster equipped with salutogenic resources, at the strategic as well as tactical levels.


2021 ◽  
pp. 6-11
Author(s):  
Brendon Albertson

A Computer-Assisted Language Learning (CALL) application, TextMix, was developed as a proof-of-concept for applying Natural Language Processing (NLP) sentence chunking techniques to creating ‘sentence scramble’ learning tasks. TextMix addresses limitations of existing applications for creating sentence scrambles by using NLP to parse and scramble syntactic components of sentences, while connecting with Application Programming Interfaces (APIs) to provide repeated exposure to authentic sentences in the context of texts such as Wikipedia articles. In addition to identifying a novel application of NLP and APIs in CALL, this project highlights the need for teacher-friendly interfaces that prioritize pedagogically useful ways of chunking text.


2021 ◽  
Vol 173 ◽  
pp. 112932
Author(s):  
Yang Xu ◽  
Yuehuan Zhang ◽  
Jian Liang ◽  
Guixiang He ◽  
Xiaolong Liu ◽  
...  

Author(s):  
Tat’yana A. Fisher ◽  
◽  
Svetlana S. Kolyvanova

The aim of this paper was to study changes in the haemodynamic and psychophysiological parameters of working age men as a result of repeated exposure to contrasting temperatures, depending on the type of autonomic regulation. Materials and methods. The research involved 14 men (aged 34.77 ± 5.66 years; office workers) divided into two groups according to Kérdö index: those with the sympathetic (n = 8) and parasympathetic (n = 6) types of self-regulation. Cold conditioning followed a certain plan of exposure to contrasting temperatures. The haemodynamic and psychophysiological parameters as well as adaptive potential were assessed 20 minutes before and 20 minutes after the exposure (alternating temperature cycles). We examined the following parameters: heart rate, systolic and diastolic blood pressure, pulse and mean arterial pressure, stroke volume, cardiac output, vascular resistance, and adaptive potential according to Baevsky. Integral psychophysiological parameters were determined using the Lüscher express method. Results. Subjects with predominance of sympathetic regulation both before and after the exposure to contrasting temperatures had higher values of heart rate and cardiac output and lower vascular resistance than the parasympathicotonic group. Individuals with predominance of parasympathetic regulation showed decreased cardiac output and a significant increase in vascular resistance after the exposure compared with the initial data. We found statistically significant differences in the integral parameters “heteronomy/autonomy” and “balance of personal traits” between the groups under study before the conditioning procedures. The research indicates that repeated exposure to contrasting temperatures not only affects the haemodynamic parameters, but also changes the psychophysiological parameters, motivated behaviour in particular. For citation: Fisher T.A., Kolyvanova S.S. Effect of Repeated Exposure to Contrasting Temperatures on the Body of Working Age Men with Different Types of Autonomic Regulation. Journal of Medical and Biological Research, 2021, vol. 9, no. 4, pp. 394–404. DOI: 10.37482/2687-1491-Z077


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 772-772
Author(s):  
James Miller ◽  
Gloria Luong

Abstract Research examining age differences in affect reactivity (i.e. how much affective experiences change in response to stressors) has produced mixed results, suggesting that there are areas of relative strength and weakness in regulatory processes across age-groups. The present study’s goals were to examine potential age-group differences in affect reactivity and subjective task-appraisals across repeated exposures to a psychosocial laboratory stressor. In the Health and Daily Experiences (HEADE) study, younger (18-35 years old; n=107) and older adults (60-90 years old; n=90) were exposed to the Trier Social Stress Test on three occasions in a laboratory setting over a five-day period. Current affective experiences and task-appraisals were assessed at each session using validated self-report scales, with current affective experiences measured at baseline and task periods to determine affect reactivity. Repeated measures ANOVA analyses were conducted to examine age-group differences in affect reactivity and task-appraisals across sessions. In support of our hypotheses, younger adults showed greater reductions in their negative affect reactivity over time compared to older adults [F(2, 390)= 8.18, p<.001]. Additionally, younger adults’ appraisals of task-difficulty decreased [F(2, 384)= 14.79, p<.001] and appraisals of task-performance increased [F(2,384)= 13.39, p<.001] across sessions, while older adults’ task-appraisals remained stable. Age-group differences in negative affect reactivity and task-difficulty appraisals were not evident for the first session and only emerged after repeated exposure to the stressors. These results highlight the importance of identifying age-related vulnerabilities in adapting to repeated stressors, with implications for designing effective interventions aimed at improving health and well-being for older adults.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eun-Hwa Lee ◽  
Jin-Young Park ◽  
Hye-Jin Kwon ◽  
Pyung-Lim Han

AbstractChronic stress induces adaptive changes in the brain via the cumulative action of glucocorticoids, which is associated with mood disorders. Here we show that repeated daily five-minute restraint resolves pre-existing stress-induced depressive-like behavior in mice. Repeated injection of glucocorticoids in low doses mimics the anti-depressive effects of short-term stress. Repeated exposure to short-term stress and injection of glucocorticoids activate neurons in largely overlapping regions of the brain, as shown by c-Fos staining, and reverse distinct stress-induced gene expression profiles. Chemogenetic inhibition of neurons in the prelimbic cortex projecting to the nucleus accumbens, basolateral amygdala, or bed nucleus of the stria terminalis results in anti-depressive effects similarly to short-term stress exposure, while only inhibition of neurons in the prelimbic cortex projecting to the bed nucleus of the stria terminalis rescues defective glucocorticoid release. In summary, we show that short-term stress can reverse adaptively altered stress gains and resolve stress-induced depressive-like behavior.


2021 ◽  
Vol 12 (11) ◽  
pp. 931-937
Author(s):  
James Robinson ◽  
Kevin P Smidt ◽  
Garrett Houk ◽  
Janay McKie ◽  
R Shane Barton ◽  
...  

2021 ◽  
Author(s):  
◽  
Natasha Bukholt

<p>Background: MDMA preferentially releases serotonin (5HT) but following repeated exposure there is a decrease in this MDMA-produced effect. At the same time, some studies suggest an increase in MDMA-produced dopamine (DA) release following repeated exposure. The sensitised DA response is often accompanied by sensitisation of MDMA-produced locomotor activity. Because DAergic mechanisms have been implicated in the positively reinforcing properties of MDMA, these neuroadaptations might be relevant to MDMA self-administration.  Objectives: The main objective of this study was to determine whether MDMA self-administration and non-contingent MDMA exposure differentially affected the development of sensitisation to MDMA-produced hyperactivity. Additionally, the relationship between MDMA-produced hyperactivity and changes in c-fos expression in DA terminal regions was determined.  Methods: Triads of rats were designated ‘master’, ‘yoked MDMA’, or ‘yoked saline’. Lever press responding by the master rat resulted in an intravenous infusion of MDMA for both the master rat and the yoked MDMA rat, as well as an equal infusion of vehicle for the yoked control rat. Daily tests continued until a total of 350 mg/kg MDMA had been self-administered. Three days following the last self-administration session, forward and vertical locomotion produced by MDMA (5.0 mg/kg, i.p) were measured during a 2 hr test. Rats were sacrificed immediately following the behavioural test, and c-fos immunohistochemistry was measured.  Results: Repeated MDMA exposure resulted in sensitised forward and vertical locomotor activity. Sensitisation of the increase in forward locomotion was produced only in rats that self-administered MDMA; non-contingent MDMA administration failed to sensitise this behavioural response. In contrast, sensitisation to MDMA-produced vertical activity was produced following both contingent and non-contingent MDMA exposure. C-fos expression was reduced in ventrolateral, and ventromedial areas of the dorsal striatum, as well as the infralimbic cortex, after MDMA exposure, regardless of whether the exposure was via self-administration or yoked administration. A selective decrease in c-fos expression in the nucleus accumbens (NAc) core and the cingulate cortex was produced by MDMA self-administration. There was a negative correlation between MDMA-produced forward locomotor activity and MDMA-produced c-fos expression in the NAc core, cingulate cortex and infralimbic cortex. A negative correlation between rearing activity and MDMA-produced c-fos expression in the NAc core, NAc shell, cingulate cortex, and infralimbic cortex was also found.  Conclusions: These data provide evidence of behavioural sensitisation as a result of repeated MDMA exposure. Furthermore, MDMA-produced behavioural sensitisation was associated with a decrease in c-fos expression that was evident in the NAc and prefrontal cortex. Finally, region-specific changes in c-fos expression suggest an important role of neuroadaptations in the NAc core and the infralimbic cortex as a consequence of MDMA self-administration.</p>


2021 ◽  
Author(s):  
◽  
Ross van de Wetering

<p>Rationale. ±3, 4-methelynedioxymethamphetamine (MDMA) is the primary psychoactive ingredient of the increasingly popular recreational street drug, ecstasy. As with other drugs of abuse, repeated intermitted exposure to MDMA can lead to an increase in the subsequent behavioural effects of the drug. This phenomenon, termed behavioural sensitisation, has been attributed to sensitisation of central DAergic mechanisms considered to underlie several aspects of addiction.  Objectives. The purpose of the present research was to investigate the role of DA D₂ receptor mechanisms in the development of MDMA sensitisation and the acquisition of MDMA self-administration in rats.  Methods. Rats received daily i.p. injections of the selective D₂ antagonist, eticlopride (0.0, 0.05, 0.3 mg/kg), prior to injections of MDMA (0.0, 10.0 mg/kg) for five days. Two days following the final pre-treatment session, the locomotor activating effects of MDMA (5 mg/kg, i.p.) were determined. Another group of rats were surgically implanted with i.v. jugular catheters before undergoing the same pre-treatment regimen. Two days following the final pre-treatment session, these rats were subsequently tested for acquisition of MDMA self-administration. The locomotor activating effects of MDMA (5 mg/kg i.p.) were determined two days following the last self-administration session.  Results. Pre-treatment with MDMA enhanced the locomotor activating effects of MDMA and facilitated the acquisition of MDMA self-administration, as evidenced by an increased likelihood to meet an acquisition criterion. Co-administration of eticlopride during pre-treatment completely blocked the development of sensitisation to MDMA-produced hyperactivity but failed to significantly attenuate the facilitation of MDMA self-administration. Interestingly, pre-treatment with eticlopride alone also facilitated the acquisition of self-administration. MDMA self-administration failed to alter MDMA-produced locomotor hyperactivity.  Conclusions. These findings suggest that repeated activation of DA D₂ receptors is required for the development of sensitisation to MDMA-produced hyperactivity but not for the development of sensitisation to MDMA-produced reinforcement. D₂ receptor mechanisms evidently play some role, however, because repeated exposure to eticlopride also facilitated MDMA self-administration. It is suggested that both sensitised DAergic mechanisms and desensitised 5-HTergic mechanisms contribute to the acquisition of MDMA self-administration.</p>


2021 ◽  
Author(s):  
◽  
Natasha Bukholt

<p>Background: MDMA preferentially releases serotonin (5HT) but following repeated exposure there is a decrease in this MDMA-produced effect. At the same time, some studies suggest an increase in MDMA-produced dopamine (DA) release following repeated exposure. The sensitised DA response is often accompanied by sensitisation of MDMA-produced locomotor activity. Because DAergic mechanisms have been implicated in the positively reinforcing properties of MDMA, these neuroadaptations might be relevant to MDMA self-administration.  Objectives: The main objective of this study was to determine whether MDMA self-administration and non-contingent MDMA exposure differentially affected the development of sensitisation to MDMA-produced hyperactivity. Additionally, the relationship between MDMA-produced hyperactivity and changes in c-fos expression in DA terminal regions was determined.  Methods: Triads of rats were designated ‘master’, ‘yoked MDMA’, or ‘yoked saline’. Lever press responding by the master rat resulted in an intravenous infusion of MDMA for both the master rat and the yoked MDMA rat, as well as an equal infusion of vehicle for the yoked control rat. Daily tests continued until a total of 350 mg/kg MDMA had been self-administered. Three days following the last self-administration session, forward and vertical locomotion produced by MDMA (5.0 mg/kg, i.p) were measured during a 2 hr test. Rats were sacrificed immediately following the behavioural test, and c-fos immunohistochemistry was measured.  Results: Repeated MDMA exposure resulted in sensitised forward and vertical locomotor activity. Sensitisation of the increase in forward locomotion was produced only in rats that self-administered MDMA; non-contingent MDMA administration failed to sensitise this behavioural response. In contrast, sensitisation to MDMA-produced vertical activity was produced following both contingent and non-contingent MDMA exposure. C-fos expression was reduced in ventrolateral, and ventromedial areas of the dorsal striatum, as well as the infralimbic cortex, after MDMA exposure, regardless of whether the exposure was via self-administration or yoked administration. A selective decrease in c-fos expression in the nucleus accumbens (NAc) core and the cingulate cortex was produced by MDMA self-administration. There was a negative correlation between MDMA-produced forward locomotor activity and MDMA-produced c-fos expression in the NAc core, cingulate cortex and infralimbic cortex. A negative correlation between rearing activity and MDMA-produced c-fos expression in the NAc core, NAc shell, cingulate cortex, and infralimbic cortex was also found.  Conclusions: These data provide evidence of behavioural sensitisation as a result of repeated MDMA exposure. Furthermore, MDMA-produced behavioural sensitisation was associated with a decrease in c-fos expression that was evident in the NAc and prefrontal cortex. Finally, region-specific changes in c-fos expression suggest an important role of neuroadaptations in the NAc core and the infralimbic cortex as a consequence of MDMA self-administration.</p>


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