Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

大学二年级学生人际宽恕与报复心理及其与抑郁的关系研究

采用沉思量表、报复动机量表、宽恕倾向量表、宽恕态度量表和流调中心用抑郁量表对236名大二学生进行问卷调查,综合探讨大学生人际宽恕和报复心理及其与抑郁的关系。研究发现:(1)男大学生的报复倾向显著高于女大学生。(2)宽恕倾向与报复倾向及对侵犯的沉思程度显著负相关。沉思程度和抑郁显著正相关。(3)沉思程度和宽恕倾向对抑郁分别具有显著的正向和负向的预测作用。(4)大学生的宽恕倾向和宽恕态度的相互作用以及宽恕倾向和报复倾向之间的交互作用对抑郁均没有显著预测作用。     

A convergent validity study of Cloninger's Temperament and Character Inventory with the Coolidge Axis II Inventory.

This study examined the convergent validity of the Temperament and Character Inventory (TCI), a measure of four biosocial temperaments and three character dimensions with the Coolidge Axis II Inventory (CATI), a measure of 14 personality disorders. A nonclinical sample of 163 college students was given both measures, and the data were analyzed with bivariate and multivariate statistics. Hypotheses generated from the findings of Svrakic, Whitehead, Przybeck, and Cloninger (1993, Archives of General Psychiatry, 50, 991-999) were confirmed for a majority of the relationships between the two measures. The preliminary results provide qualified support for the TCI and Cloninger's biosocial theory in the assessment of personality disorders.     

Information processing bias against emotional facial expressions in social anxiety

The present study examined whether information processing bias against emotional facial expressions is present among individuals with social anxiety. College students with high (high social anxiety group; n  = 26) and low social anxiety (low social anxiety group; n  = 26) performed three different types of working memory tasks: (a) ordering positive and negative facial expressions according to the intensity of emotion; (b) ordering pictures of faces according to age; and (c) ordering geometric shapes according to size. The high social anxiety group performed significantly more poorly than the low social anxiety group on the facial expression task, but not on the other two tasks with the nonemotional stimuli. These results suggest that high social anxiety interferes with processing of emotionally charged facial expressions.     

Word and letter string processing networks in schizophrenia: evidence for anomalies and compensation

Imaging studies show that in normal language correlated activity between anterior and posterior brain regions increases as the linguistic and semantic content (i.e., from false fonts, letter strings, pseudo words, to words) of stimuli increase. In schizophrenia however, disrupted functional connectivity between frontal and posterior brain regions has been frequently reported and these disruptions may change the nature of language organization. We characterized basic linguistic operations in word and letter string processing in a region-of-interest network using structural equation modeling (SEM). Healthy volunteers and volunteers with schizophrenia performed an fMRI one-back matching task with real words and consonant letter strings. We hypothesized that left hemisphere network dysfunction in schizophrenia would be present during processes dealing with linguistic/semantic content. The modeling results suggest aberrant left hemisphere function in schizophrenia, even in tasks requiring minimal access to language. Alternative mechanisms included increases in right hemisphere involvement and increased top-down influence from frontal to posterior regions.     

Toward an Integration of Interpersonal Risk Models of Depression and Cognitive‐Behaviour Therapy

Empirical research has increasingly focused on interpersonal variables associated with the development and maintenance of depression. This article outlines some key interpersonal risk factors for depression, including anxious attachment, sociotropy, excessive reassurance seeking, interpersonal stress generation, reduced social support, social skills deficits, and social avoidance. Recommendations are made for how cognitive‐behavioural therapy may be adapted to address such factors. Specifically, suggestions are offered for how cognitive and behavioural interventions, such as cognitive restructuring, behavioural activation, behavioural experiments, and skills training, may be used with depressed clients to promote positive relationships and reduce maladaptive interpersonal behaviours.     

Adult age differences in function concept learning

Function concept learning and knowledge use was explored across adulthood. During training older and younger adults predicted an amount of physiological arousal produced as a negative and positive function of a chemical substance. Knowledge use was evaluated with two transfer conditions requiring a switch between contextual contingencies: a relationship inversion, predicting the chemical amount given the physiological arousal, and a change from graphic based to text based stimuli. Older adults were impaired in applying the negative slope concept. However, there was no relative deficit in switching between the negative and positive function slopes or inverting the learned relationship. Our results suggest that age-related differences in relational reasoning tasks vary not only with processing efficiency, but also task related conceptual knowledge.     

Transformational and derivational strategies in analogical problem solving

Analogical problem solving is mostly described as transfer of a source solution to a target problem based on the structural correspondences (mapping) between source and target. Derivational analogy (Carbonell, Machine learning: an artificial intelligence approach Los Altos. Morgan Kaufmann, 1986) proposes an alternative view: a target problem is solved by replaying a remembered problem-solving episode. Thus, the experience with the source problem is used to guide the search for the target solution by applying the same solution technique rather than by transferring the complete solution. We report an empirical study using the path finding problems presented in Novick and Hmelo (J Exp Psychol Learn Mem Cogn 20:1296–1321, 1994) as material. We show that both transformational and derivational analogy are problem-solving strategies realized by human problem solvers. Which strategy is evoked in a given problem-solving context depends on the constraints guiding object-to-object mapping between source and target problem. Specifically, if constraints facilitating mapping are available, subjects are more likely to employ a transformational strategy, otherwise they are more likely to use a derivational strategy.