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.     

A technique for controlling speech disfluencies induced by delayed auditory feedback

On the basis of cybernetic models of speech it was hypothesized that “stuttering” induced by delayed auditory feedback could be significantly reduced if the Ss were provided with an alternate input to which they could attend. The results of the experiment supported the hypothesis. The possible implications for the treatment stuttering are discussed.     

Ryle on knowing how: Some clarifications and corrections

I argue for an account of know‐how as a capacity for practical judgment—a view I derive from Gilbert Ryle. I begin by offering an interpretation of Ryle and by correcting a number of widespread misconceptions about his views in the current debate. I then identify some problems with Ryle's account and finally present my own view which, I argue, retains Ryle's insights while avoiding his mistakes.     

Epidemiological Measurement of Children's and Adolescents' Exposure to Community Violence: Working with the Current State of the Science

A number of measures have been used in epidemiological studies of children's exposure to community violence, yet the quality of these instruments is not uniformly good. This paper undertakes a systematic review of the most commonly used (or most promising) self-report or interview-administered instruments, with regard to their conceptual bases and psychometric properties. Based on the review, recommendations are made for working with the current state of the science in order to move the field forward. A key recommendation is for sounder conceptualization of work in the field and greater transparency in the reporting of research, in order to facilitate the comparability of studies.     

To Love or Hate Thy Neighbor: The Role of Authoritarianism and Traditionalism in Explaining the Link Between Fundamentalism and Racial Prejudice

Fundamentalism is consistently related to racial prejudice (Hall, Matz, & Wood, 2010), yet the mechanisms for this relationship are unclear. We identify two core values of fundamentalism, authoritarianism and traditionalism, that independently contribute to the fundamentalism‐racial prejudice relationship. We also contextualize the fundamentalism‐racial prejudice relationship by suggesting that fundamentalists may show prejudice based on conceptions of African Americans as violating values but show tolerance when prejudice is less justifiable. These ideas are tested and confirmed using three data sets from the American National Election Studies. Across all three samples, fundamentalism is related to increases in symbolic racism but decreases in negative affect towards African Americans, and these relationships are mediated by both authoritarianism and traditionalism.