Effects of arterial cannulation stress on regional cerebral blood flow in major depressive disorder

Individuals with major depressive disorder (MDD) display abnormal neurophysiological responses to psychological stress but little is known about their neurophysiological responses to physiological stressors. Using [15O-H2O] positron emission tomography we assessed whether the regional cerebral blood flow (rCBF) response to arterial cannulation differed between patients with MDD and healthy controls (HCs). Fifty-one MDD patients and 62 HCs were scanned following arterial cannulation and 15 MDD patients and 17 HCs were scanned without arterial cannulation. A region-of-interest analysis showed that a significantly increased rCBF of the anterior cingulate cortex and right amygdala was associated with arterial cannulation in MDD. A whole brain analysis showed increased rCBF of the right post-central gyrus, left temporopolar cortex, and right amygdala during arterial cannulation in MDD patients. The rCBF in the right amygdala was significantly correlated with depression severity. Conceivably, the limbic response to invasive physical stress is greater in MDD subjects than in HCs

The Functional DRD3 Ser9Gly Polymorphism (rs6280) Is Pleiotropic, Affecting Reward as Well as Movement

Abnormalities of motivation and behavior in the context of reward are a fundamental component of addiction and mood disorders. Here we test the effect of a functional missense mutation in the dopamine 3 receptor (DRD3) gene (ser9gly, rs6280) on reward-associated dopamine (DA) release in the striatum. Twenty-six healthy controls (HCs) and 10 unmedicated subjects with major depressive disorder (MDD) completed two positron emission tomography (PET) scans with [11C]raclopride using the bolus plus constant infusion method. On one occasion subjects completed a sensorimotor task (control condition) and on another occasion subjects completed a gambling task (reward condition). A linear regression analysis controlling for age, sex, diagnosis, and self-reported anhedonia indicated that during receipt of unpredictable monetary reward the glycine allele was associated with a greater reduction in D2/3 receptor binding (i.e., increased reward-related DA release) in the middle (anterior) caudate (p<0.01) and the ventral striatum (p<0.05). The possible functional effect of the ser9gly polymorphism on DA release is consistent with previous work demonstrating that the glycine allele yields D3 autoreceptors that have a higher affinity for DA and display more robust intracellular signaling. Preclinical evidence indicates that chronic stress and aversive stimulation induce activation of the DA system, raising the possibility that the glycine allele, by virtue of its facilitatory effect on striatal DA release, increases susceptibility to hyperdopaminergic responses that have previously been associated with stress, addiction, and psychosis

Outcome of experimental stroke in C57Bl/6 and Sv/129 mice assessed by multimodal ultra-high field MRI

Transgenic mice bred on C57Bl/6 or Sv/129 genetic background are frequently used in stroke research. It is well established that variations in cerebrovascular anatomy and hemodynamics can influence stroke outcome in different inbred mouse lines. We compared stroke development in C57Bl/6 and Sv/129 mice in the widely used model of transient middle cerebral artery occlusion (tMCAO) by multimodal ultra-high field magnetic resonance imaging (MRI)

After the riot: the meaning for multicultural Australia

This report presents speeches from a panel discussion on what the Sydney riot means for Australia\u27s status as a peaceful and harmonious multicultural society. The riot on 15 September in the Sydney CBD by Muslim protestors angry the US film Innocence of Muslims shocked, but perhaps did not surprise, many Australians. For a number of years, there has been growing community concern about the integration of some Muslim citizens into the Australian community. Most concern has centered on the ethnic enclaves of south west Sydney, around the suburbs of Lakemba and Bankstown, which have a high proportion of Muslim residents, many with a Lebanese background. Among thinking Australians, these concerns are not a manifestation of inherent prejudice; they are prompted by legitimate questions. Australian society has a long track record of successfully integrating migrants from diverse backgrounds. But, as the Sydney riots demonstrated, something appears to have gone wrong with a sub-set of a sub-set of newcomers. A common way of expressing these concerns was to wonder what the riot means for Australia’s status as a peaceful and harmonious multicultural society. To answer this question, The Centre for Independent Studies decided to convene a forum to discuss the relevant issues. The forum was held at the CIS office at St Leonards on 27 September 2012 featuring speeches by three researchers. These speeches are reproduced in this Policy Forum. Not all the speakers agreed with each other about all aspects of the topic. This is as it should be when dealing with contentious and fluid events. Benjamin Herscovitch argued that multiculturalism remains an overall success in Australia and the hallmark of a free society. Peter Kurti argued that in a multiculturalism society, key liberal values such as tolerance must be embraced by all racial, religious, and ethnics groups, especially as liberal democracy is fundamentally incompatible with the intolerance preached by radical Islamists. Jeremy Sammut argued that the emphasis multiculturalism places on diversity will prove a threat to freedom and liberal democracy if Islamofascist demands for restrictions on free speech are allowed out of a misplaced ‘respect for diversity’