Adrenalectomy Causes Oxidative Damage and Monoamine Increase in the Brain of Rats and Enhances Immobilization Stress-Induced Oxidative Damage and Neurotransmitter Changes

The paradox that increased levels of glucocorticoids can either enhance or suppress the organism's defense against stress, has been an obstacle to formulating a unified picture of glucocorticoid function. To clarify the glucocorticoid paradox, we examined male Sprague-Dawley rats exposed to immobilization stress and/or bilateral adrenalectomy (ADX), and measured oxidative damage to lipid, protein, and DNA, as well as monoamine neurotransmitter turnover. ADX, which is similar to stress, induces an increase in lipid peroxidation and protein oxidation, accompanied by increased monoamine neurotransmitter turnover in several regions of the brain of rats. The effect of ADX is greater than that induced by short-term immobilization stress. In addition, ADX enhances stress-induced oxidative damage and increase of monoamine neurotransmitter turnover. These results, together with our previous finding that long-term stress causes oxidative damage to the brain, suggest that stress levels of glucocorticoids, or levels lower than basal, cause oxidative damage. However, basal levels of glucocorticoids appear to buffer against oxidative damage. These findings provide possible mechanisms to understand the glucocorticoid paradox, and support the stress-oxidative hypothesis of aging acceleration.     

Involvement of reactive oxygen species in emotional stress: A hypothesis based on the immobilization stress-induced oxidative damage and antioxidant defense changes in rat brain,and the effect of antioxidant treatment with reduced glutathione

We examined the oxidative damage and antioxidant defense changes with immobilization-induced emotional stress in the rat brain. Though superoxide dismutase activity remained unchanged, brain peroxidation was significantly accelerated by the immobilization stress. Membrane fluidity study with spin labeling in brain cortical membrane showed that immobilization stress induced an increase in microviscosity of membrane layer near the surface and in the ordering of membrane proteins but a decrease in microviscosity at the core of the membrane bilayer. The Na, K-ATPase activity decreased whereas the levels of some monoamines and their metabolites increased along with their metabolic rate. The administration of reduced glutathione showed a protective effect on the immobilization stress-induced stomach bleeding, oxidative damage and abnormal changes in the brain antioxidant defenses. Based on these results and on previous reports, we hypothesize that immobilization stress may induce the formation of reactive oxygen species which weakens the brain antioxidant defenses and induces oxidative damage. The antioxidant administration of reduced glutathione provides further evidence to support the above hypothesis, and also may provide clues in the search for a rational therapy to emotional stress. A possible correlation of emotional stress to aging is also discussed.     

The aggression test as a taxonomic tool: Evaluation in sympatric and allopatric populations of wood-ant species

Ant-workers of Formica lugubris and F. rufa from colonies living sympatrically (from the same area) and allopatrically (from different areas) were tested in pairs using a laboratory aggression test. The aim was to verify whether sharing the same area of origin influences the relationships among heteroeolonials between and within these species which belong to the F. rufa group. The results suggest that a similar degree of agonistic behaviour (ritualised aggression) was shown in sympatric and allopatric conspecific dyads of both species studied. The interactions between F. lugubris and F. rufa were characterised by a low level of overt aggression both in sympatric and allopatric pairs, confirming the interspecific tolerance observed in our previous studies on these wood-ant species. This reduced aggressiveness between workers of F. lugubris and F. rufa coming from the same or a different area can be interpreted on the basis of their sharing common signals, such as odours and patterns of behaviour. Therefore, their mutual tolerance and acceptance can be indicative of a phylogenetic closeness between such species. We propose that an aggression test can be a valid tool for elucidating systematic problems in this taxonomically difficult group of ants. © 1993 Wiley-Liss, Inc.     

Popular psychological tests and self-fulfilling prophecy: An experiment of Japanese female undergraduate students

The purpose of this study was to examine whether or not the feedback of the results of popular psychological tests influences human behavior, and to compare the strength of any influence with that of academic psychological tests. We conducted an experiment in which 64 female Japanese subjects took a popular or academic psychological test, and then interacted with a stranger. The subjects who took each test received bogus feedback implying that they were extroverted or introverted. The results showed that subjects who received the extroversion feedback were more interactive with a stranger than those who received the introversion feedback, irrespective of whether they had taken the popular or academic test. This suggests that the feedback of popular psychological tests, like that of academic tests, can influence human behavior and create a self-fulfilling prophecy. The results also showed that those subjects who took the popular psychological tests reported higher psychological well-being than those who took the academic tests.     

Hand preference consistency and eye-hand coordination in young children during a motor task

Indications of earlier research are that individuals exhibiting a consistent hand preference are better coordinated on selected motor tasks than peers with inconsistent hand preference. The present study examined eye-hand coordination via inter- and intramodal matching behavior by handedness groups for 55 5- and 6-yr.-olds using the Pinboard Test. Analysis indicated the Consistent group scored better, leading to the speculation that children with consistent laterality may possess an advantage in interhemispheric communication, especially when the task requires coordination of both limbs.     

Influence of Deteriorating Ability of Emotional Comprehension on Interpersonal Behavior in Alzheimer-Type Dementia

This study investigated the relationship between the ability to recognize emotion and interpersonal behavior in dementia of the Alzheimer type (DAT). After examining the validity and reliability of the Emotion Recognition Test (ERT), an improved version of the tasks used by Shimokawa et al. (2000), 100 patients with DAT underwent evaluation for general cognition using the Mini-Mental State Examination (MMSE) and emotion recognition using the ERT. Within a week of these tests being administered, ward staff rated the patients using the Interpersonal Behavior Checklist (IBC), composed of two behavior scales: indifference to interpersonal relationships and difficulties with patient treatment/management. After investigating the validity and reliability of the scales, the correlations between the MMSE, the ERT, and the two scales of the IBC were calculated. The results suggested that the MMSE did not correlate with either of the two behavior scales, while the ERT correlated significantly with both of the scales. The study results lead to the conclusion that deteriorating emotion recognition ability, rather than deterioration of general cognition, influences the indifferent and awkward interpersonal behaviors of DAT patients.     

Projecting two words with one machine: Presenting two different visual stimuli using just one projector without viewers’ noticing the duality

A new method, named the fMORI technique, for presenting two different visual stimuli using just one video projector without the viewers' noticing the duality is introduced along with several sample applications of this presentation method. The LCD projectors available now have three color LCD panels aligned differently in terms of their polarization, polarizing differently the green and magenta (red plus blue) components of its emitting image. Therefore, two visual stimuli either in green or in magenta projected on thesame screen canbe observed separately by subjects wearing an appropriate polarizing filter. This is a variation of the MORI technique (Mori, 2003, 2007b) but it requires only one video projector rather than two. Full-color movies cannot be presented with the fMORI technique, but it may be utilized in various research areas in which only static monochrome visual stimuli, such as words or numbers, are used.     

Asymmetrical drawing patterns on the temples by left-handers

Twenty-three Japanese genuine left-handers were selected by a Laterality Quotient scale and asked to draw the letter S on their own temples and foreheads. The way they drew on the temples showed an asymmetry that was the mirror reversal of that of right-handers, as found in a previous study. Left-handers drew a reversed letter S on their right temple much more often than on the left temple, whereas right-handers drew them in reverse more often on the left temple. They also drew it in reverse on the forehead irrespective of their handedness.     

Effects of temperature and electron energy on the electron-irradiation-induced decomposition of sapphire

The effects of temperature and electron energy on the electron-irradiation-induced decomposition of sapphire have been investigated by in situ transmission electron microscopy (TEM). It was found that the decomposition rate of α-Al₂O₃ increased with increasing irradiation temperature and decreased with increasing acceleration voltage. The core-hole Auger decay process (K–F model), rather than knock-on displacement, is responsible for the decomposition of α-Al₂O₃ under electron irradiation.     

Retention and thermal desorption of helium in amorphous and crystalline FeBSi alloys

Helium retention in metals is related to their atomic structure and the type of defects they contain. In order to investigate the dependence of helium retention on structure, amorphous Fe₇₉B₁₆Si₅ and crystalline FeBSi alloys were irradiated by helium ions at room temperature. In the crystalline alloy irradiated with 5 keV He⁺ ions, three types of helium trapping sites were found: surface defects produced by the irradiation, interstitial-type dislocation loops, and voids. Although these defects did not exist in the amorphous FeBSi alloy, we did observe thermal desorption peaks related to all three types. In addition, helium was released during the crystallization of amorphous FeBSi that had been irradiated by He⁺ ions.