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.     

Integration of Test Results with Clinical Observations A Diagnostic Case Study

In this study, we aimed to investigate the application of an externally rated measure of interpersonal representations (Social Cognition and Object Relations Scale [SCORS]; Westen, 1995) to dream narratives. A total of 80 student participants enrolled at a private university in the New York City metropolitan area completed a Dream Log and affect adjective checklist (Wellman, 2002) based on a recalled dream at both 1 month and 3 months following the September 11, 2001, terrorist attacks. Using the dreams provided in this study we examined the interrater reliability of SCORS ratings, the relationship of SCORS variables to an independently rated measure of dream distortion, and the relationship of SCORS variables to participants' own ratings of dream affect. Results indicated that dreams were reliably rated using the SCORS, 3 cognitive SCORS variables were significantly related to dream distortion, and affective SCORS variables were meaningfully related to participants' own ratings of affect in their dreams. Findings from this study provide support for the application of SCORS ratings to dream narratives. We discuss implications for further research and clinical application.     

An Introductory Lecture on Personality Assessment

The role of personality assessment is minimized in many introductory psychology presentations for a variety of reasons. Personality assessment is an area of great breadth and is understandably formidable to those whose training has been outside this area of specialization.

The following lecture was designed to digest at least some parts of the area of personality assessment in as non-technical language as possible for use of instructors introducing its basic concepts.     

Psychological stress and blood glucose regulation in type I diabetic patients

Fifteen Type I diabetic patients self-monitored daily mean blood glucose levels (BGL), psychological stress, diet, exercise, and insulin injections for a period of 8 weeks. Separate multiple-regression analyses were conducted for each subject to assess the predictability of BGL from stress reports, independent of the effects of diet, exercise, and insulin self-administration. Considerable individual variability in findings was evident, with stress predicting BGL in a statistically significant manner in 7 of the 15 subjects. Stress had a significant effect on BGL independent of diet, exercise, and insulin administration for each of these 7 subjects. Discussion focused on the problems of measuring the key self-management behaviors influencing BGL and on the possibility that a subgroup of diabetic patients may be BGL stress responders.