E. Maldonado

Subjective Sleep Quality and hormonal modulation in long-term yoga practitioners

Yoga represents a fascinating mind-body approach, wherein body movements (asana), breathing exercises (pranayama) and meditation are integrated into a single multidimensional practice. Numerous beneficial mental and physical effects have been classically ascribed to this holistic ancient method. The purpose of the present study has been to examine the effects of long-term yoga practice on Subjective Sleep Quality (SSQ) and on several hormonal parameters of the hypothalamus-pituitary-adrenal (HPA) axis. Twenty-six subjects (16 experimental and 10 controls) were recruited to be part of the study. Experimental subjects were regular yoga practitioners with a minimum of 3 years of practice. Blood samples for the quantification of adrenocorticotropic hormone (ACTH), cortisol and dehydroepiandrosterone sulphate (DHEA-S) were drawn from all subjects. Likewise, the Pittsburgh Sleep Quality Index (PSQI) was employed to assess SSQ. As statistical analysis, Mann-Whitney U-test was performed. The yoga group displayed lower PSQI scores and higher blood cortisol levels than control subjects. Therefore, it can be concluded that long-term yoga practice is associated with significant psycho-biological differences, including better sleep quality as well as a modulatory action on the levels of cortisol. These preliminary results suggest interesting clinical implications which should be further researched.

Cognitive Performance and Morning Levels of Salivary Cortisol and α-Amylase in Children Reporting High vs. Low Daily Stress Perception

The aim of the present study was to assess the effects of daily stress perception on cognitive performance and morning basal salivary cortisol and alpha-amylase levels in healthy children aged 9-12. Participants were classified by whether they had low daily perceived stress (LPS, n = 27) or a high daily perceived stress (HPS, n = 26) using the Children Daily Stress Inventory (CDSI). Salivary cortisol and alpha-amylase were measured at awakening and 30 minutes later. Cognitive performance was assessed using the Cognitive Drug Research assessment system. The HPS group exhibited significantly poorer scores on speed of memory (p < .05) and continuity of attention (p < .05) relative to the LPS group. The HPS group also showed significantly lower morning cortisol levels at awakening and at +30 minutes measures in comparison with the LPS group (p < .05), and mean morning cortisol levels were negatively correlated with speed of memory (p < .05) in the 53 participants. No significant differences were observed between both groups in alpha-amylase levels. These findings suggest that daily perceived stress in children may impoverish cognitive performance via its modulating effects on the HPA axis activity.

Acute and subchronic effects of MDMA ("ecstasy") on anxiety in male mice tested in the elevated plus-maze.

3,4-Methylenedioxymethamphetamine (MDMA) is a compound structurally similar to methamphetamine, which has become one of the most widely used illicit substances. Animal studies investigating acute effects of MDMA on anxiety are unclear since, although an anxiogenic-like action of MDMA in different animal models of anxiety has been mainly described, there is also evidence supporting an anxiolytic-like effect for this drug. An attempt was made to clarify the possible anxiogenic-like profile of MDMA (1, 8 and 15 mg/kg i.p.) by analyzing its effect on behavior of male mice in the elevated plus-maze test. Moreover, the possible development of tolerance to the effects of MDMA on anxiety after its subchronic administration for 5 consecutive days was examined. The parameters evaluated included: (1) total time in open arms, (2) total time in closed arms, (3) total time in central area, (4) number of open arm entries, (5) number of closed arm entries and (6) number of central area entries. Acute treatment with MDMA (8 mg/kg) significantly reduced the time spent in the open arms, as well as markedly increasing the number of entries in the closed arms and in the central area, as compared with the control group, suggesting that MDMA, at this dose, has an anxiogenic-like activity. Mice subchronically treated with the drug (1 and 8 mg/kg) displayed a notable reduction in the time spent in the open arms, accompanied by an increase in the time spent in the closed arms and in the central platform. These results indicate that the anxiogenic-like effect found after acute treatment is not only maintained but also more marked after subchronic treatment. In contrast, mice treated subchronically with the highest dose of MDMA (15 mg/kg) exhibited a significant increase in the time spent in the open arms as well as a marked reduction in the time spent in the closed arms, supporting an anxiolytic-like activity of the drug. A possible dual pharmacological property of MDMA on anxiety is suggested.

Salivary cortisol response to a psychosocial stressor on children diagnosed with attention-deficit/hyperactivity disorder: differences between diagnostic subtypes.

The purpose of the present study was to compare the reactivity of the HPA-axis in children diagnosed with different subtypes of ADHD against a healthy control group. This study included a total of 66 children: 33 children with ADHD diagnoses (10 with prevalent inattentive symptoms, 9 with prevalent hyperactive-impulsive symptoms and 14 with the combined subtype) and 33 healthy controls. The Trier Stress Social Test for Children (TSST-C) was employed as stressor. This test included two main stressors: first, completing a story initiated by an interviewer, and second, executing a timed cognitive task. Saliva samples were then obtained at -1, and +1, +10, +20 and +30 minutes with respect to the stress-inducing task. While the repeated-measures ANOVA showed a statistically significant time effect, the expected cortisol stress-response was not observed in any group. A difference was observed in the response from the hyperactive-impulsive group that was also observed in the AUC(G) comparisons with the subgroups. The ADHD group with prevalent hyperactivity-impulsive symptoms showed more significantly reduced cortisol levels than the control group and other experimental subgroup with prevalent inattentive symptoms.

TIAPRIDE-INDUCED CATALEPSY IS POTENTIATED BY GAMMA-HYDROXYBUTYRIC ACID ADMINISTRATION

1. The effect of administration of gammahydroxybutyrate (GHB) and tiapride, either alone or in combination, on catalepsy behavior was examined in male mice. 2. Catalepsy was measured by bar and grid tests. Two successive evaluations were carried out 30 and 60 min after injections. 3. Tiapride (175 and 200 mg/kg) and gammahydroxybutyrate (200 mg/kg) provoked an increase of catalepsy scores, exhibiting different time courses. GHB produced a marked but short lasting catalepsy with a peak of action at 30 min, while tiapride produced a catalepsy state with a peak of action at 60 min. 4. Tiapride-induced catalepsy was potentiated by gammahydroxybutyrate administration at 30 min (bar test) and 60 min (bar and grid tests). 5. These results underlie the view that GHB interacts with central dopamine D2 transmission.

Salivary alpha-amylase changes promoted by sustained exposure to affective pictures

We studied the changes in salivary alpha-amylase (sAA) and other psychophysiological indices (heart rate, skin conductance, and corrugator supercilii activity) elicited by sustained exposure to affective pictures. Thirty-nine subjects viewed five blocks of pictures depicting mutilations, human attack, neutral scenes, sport/adventure, and erotica. Each block comprised 12 pictures of the same content. Saliva samples were collected before and after each block of pictures. The results showed that mutilation pictures promoted the greatest increase in sAA activity and output, as well as greater corrugator supercilii activity than pleasant pictures. Skin conductance response did not differ among high arousal picture contents. Changes in sAA varied with the affective valence but not with the arousal ratings of the pictures. Our results point to sAA as an index directly related to the unpleasantness elicited by sustained exposure to affective stimuli.

Occupational well-being and stress among early childhood professionals: the use of an innovative strategy to measure stress reactivity in the workplace

ABSTRACT The aim of this study was to examine early childhood professionals’ (ECPs) work engagement, burnout and stress regulation in integrated special day-care groups. The participants consisted of 89 ECPs from 21 integrated special day-care groups in Helsinki, Finland. ECPs’ work-related well-being was assessed using self-report questionnaires that measured work engagement and burnout. Stress regulation was assessed by measuring salivary cortisol and alpha-amylase activity during consecutive working and weekend day with a total five samples per day. The results indicated that ECPs experienced high levels of work engagement, and even though signs of burnout appeared among ECPs, compared to reference values in general population results showed ECPs generally experienced lower levels of stress. On average ECPs stress regulation was regular, and there were no differences in salivary AA/Cortisol or Cortisol/AA ratios between the working day and weekend day. No connections between stress regulation, work engagement and burnout were found. However, we found associations between ECPs’ characteristics and work engagement and burnout; younger ECPs showed lower professional self-esteem and ECPs with higher level qualifications (e.g. special teachers) were more likely to report higher levels of work engagement. The main findings drawn from the data are discussed, and suggestions for future research are provided.