Opioids and NMDA receptors: Neuro-excitation and abnormal pain behaviours

In the clinical setting, chronic administration of high doses of systemic morphine may result in neuro-excitatory behaviours such as myoclonus and allodynia in some patients. Additionally, high doses of m-opioid agonists such as morphine administered chronically by the intrathecal route in both rats and humans, as well as DAMGO in rats, have been reported to produce neuro-excitatory behaviours. However, more recently, it has begun to be appreciated that even at normal analgesic doses, opioids such as morphine are capable not only of activating pain inhibitory systems (analgesia/antinociception), but they also activate pain facilitatory systems such that post-opioid allodynia/hyperalgesia may be evident after cessation of opioid treatment. Whilst it is well documented that opioid receptors mediate the inhibitory effects of opioid analgesics, the excitatory and pro-nociceptive effects of opioids appear to involve indirect activation of N-methyl-D-aspartate (NMDA) receptors, such that the extent of pain relief produced may be the net effect of these two opposing actions. Apart from the NMDA-nitric oxide (NO) pro-nociceptive signaling cascade, considerable evidence also implicates dynorphin A as well as the endogenous anti-opioid peptides cholecystokinin (CCK), neuropeptide FF (NPFF) and orphanin FQ/nociceptin, in mediating opioid-induced neuro-excitation and abnormal pain behaviours. Apart from the neuro-excitatory effects that may be produced by the parent opioid, systemic administration of some opioid analgesics such as morphine and hydromorphone in rats and humans results in their rapid conversion to 3-glucuronide metabolites that also contribute significantly to the neuro-excitatory and abnormal pain behaviours produced

The relationships among teacher behaviours, teacher efficacy, and student quality of school life: A multilevel perspective

This Study invesdgated the impact of teacher behaviours on student quaUt}' of school Ufe (SQSL). A measure of teacher organisadonal cidzenship behaviour (OCB) was developed, tapping two dimensions of organisadon-focused OCB (OCBO) and one dimension of individual-focused OCB (OCBI). In Une with previous research suggesdng that OCBOs may consdtute efficacyenhancing experiences, as weU as studies demonstradng the posidve consequences of teacher efficacy for students, we expected teacher efficacy to mediate the reladonship between OCBO and SQSL. Hypotheses were tested in a muldlevel design in which 171 teachers and their students (N=3018) completed quesdonnaires. A significant propordon of variance in SQSL was attributable to classroom factors. Support was found for the main effects of OCBO, as well as the main and mediadng effects of teacher efficacy.

To learn from one's mistakes: The role of impulsivity in positive workplace behaviours

Recentiy a neuropsychological model of learning has been proposed Qackson, 2002) which argues that Responsibility provides a cognitive re-expression of Impulsivit)' in the prediction of functional and dysfunctional behaviour. Jackson argues that primitive, instinctive impulses lead to antisocial behaviours and socio-cognitive regulators such as Responsibility leads to the re-expression of Impulsivity in terms of pro-social behaviours. Study 1 tests and supports the measurement properties of the assessment methodology associated with the model. Study 2 provides evidence in favour of the instinctive basis of Impulsivity and the conscious basis of Responsibility, which reinforces the underlying neuropsychological basis of the model. Study 3 uses structural equation modelling to determine if Responsibility mediates Impulsivity in the prediction of a latent variable representing work performance, work commitment and team performance, but does not mediate Impulsivit}' in the prediction of a latent variable representing sexual proclivity, workplace deviancy, gambling and beer consumption. Results provide strong support for Jackson's model and suggest that Impulsivity and Responsibility are fundamental to both functional and dysfunctional learning

The relationship between extra-role behaviours and job burnout for primary school teachers: A preliminary model and development of an organisational citizenship behaviour scale

Recent research on teacher stress in primary schools (e.g. Leonard, Bourke & Schofield, 1999) has shown that higher levels of teacher exhaustion are associated with higher levels of student satisfaction. This paper seeks to explain this surprising finding by considering a construct discussed widely in the organisational literature known as extra-role or organisational citizenship behaviour (OCB). Teacher OCB may include extra efforts to make lessons enjoyable and interesting, organising extra-curricular activities and spending personal time talking with students. The proposed model of analysis also draws on literature relating to job burnout (Maslach, 1982), which generally suggests that the three components of chronic occupational stress - exhaustion, depersonalisation and reduced accomplishment - occur together. However, this paper proposes that although teachers who engage in more OCB experience more exhaustion, they may simultaneously increase their feelings of personal accomplishment and work identification, which may in turn help to avert burnout. It is argued that only with this particular set of job attitudes are the effects of exhaustion caused by high levels of OCB sufficiently buffered to avoid job burnout, and thus positively affect students' quality of school life. The development and piloting of an instrument to measure teachers' OCB will be discussed. The preliminary findings reported herein are part of a larger ongoing study investigating the consequences of stress and OCB in primary school teachers.

The moderating effect of aural preference on neuroticism in the prediction of disinhibited behaviours

ISSID 2005