Effect of angiotensin-related antihypertensives on brain neurotransmitter levels in rats.

The extensive clinical experience of angiotensin converting enzyme inhibitors and angiotensin AT(1) receptor antagonists as antihypertensive agents provide numerous examples of anecdotal evidence of improvements in cognition and mood. This study aimed to determine the effect of chronic treatment with the angiotensin converting enzyme inhibitor, perindopril, and the angiotensin AT(1) receptor antagonist, candesartan, on central neurotransmitter levels in the rat. Perindopril (1.0mg/kg/day) or candesartan (10mg/kg/day) was administered via the drinking water at for 1 week, while controls received water alone. At the end of treatment rats were sacrificed, brains removed and discrete regions dissected and analysed for noradrenaline, dopamine and its major metabolites, and serotonin content. As shown previously we found an increase in striatal dopamine levels after perindopril treatment, though this did not extend to the mesolimbic system with neurotransmitter levels unchanged in the hippocampus, nucleus accumbens and frontal cortex. Conversely, candesartan administration produced no change in dopamine, but significant decreases in both DOPAC and HVA in the striatum. In addition chronic candesartan infusion produced a significant increase in the levels of hippocampal noradrenaline and serotonin; and frontal cortex serotonin content. These results demonstrate that while angiotensin converting enzyme inhibitors and angiotensin AT(1) receptor antagonists act as antihypertensives by affecting the renin-angiotensin system, they have divergent actions on brain neurochemistry.

Insulin receptor substrate-2 deficiency impairs brain growth and promotes tau phosphorylation

Insulin resistance and diabetes might promote neurodegenerative disease, but a molecular link between these disorders is unknown. Many factors are responsible for brain growth, patterning, and survival, including the insulin-insulin-like growth factor (IGF)-signaling cascades that are mediated by tyrosine phosphorylation of insulin receptor substrate (IRS) proteins. Irs2 signaling mediates peripheral insulin action and pancreatic beta-cell function, and its failure causes diabetes in mice. In this study, we reveal two important roles for Irs2 signaling in the mouse brain. First, disruption of the Irs2 gene reduced neuronal proliferation during development by 50%, which dissociated brain growth from Irs1-dependent body growth. Second, neurofibrillary tangles containing phosphorylated tau accumulated in the hippocampus of old Irs2 knock-out mice, suggesting that Irs2 signaling is neuroprotective. Thus, dysregulation of the Irs2 branch of the insulin-Igf-signaling cascade reveals a molecular link between diabetes and neurodegenerative disease.

Interviewing children with acquired brain injury (ABI).

Research into the lives of children with acquired brain injury (ABI) often neglects to incorporate children as participants, preferring to obtain the opinions of the adult carer (e.g. McKinlay et al., 2002). There has been a concerted attempt to move away from this position by those working in children’s research with current etiquette highlighting the inclusion of children and the use of a child-friendly methodology (Chappell, 2000). Children with disabilities can represent a challenge to the qualitative researcher due to the combination of maintaining the child’s attention and the demands placed on them by their disability. The focus of this article is to discuss possible impediments to interviewing children with acquired brain injury (ABI) and provide an insight into how the qualitative researcher may address these.

Healthcare professionals’ attitudes towards traumatic brain injury (TBI): The influence of profession, experience, aetiology and blame on prejudice towards survivors of brain injury

Primary objective: To investigate the attitudes of healthcare professionals towards individuals with traumatic brain injury (TBI) and their relationship to intended healthcare behaviour.

Research design: An independent groups design utilized four independent variables; aetiology, group, blame and gender to explore attitudes towards survivors of brain injury. The dependent variables were measured using the Prejudicial Evaluation and Social Interaction Scale (PESIS) and Helping Behaviour Scale (HBS).

Methods and procedures: A hypothetical vignette based methodology was used. Four hundred and sixty participants (131 trainee nurses, 94 qualified nurses, 174 trainee doctors, 61 qualified doctors) were randomly allocated to one of six possible conditions.

Main outcomes and results: Regardless of aetiology, if an individual is to blame for their injury, qualified healthcare professionals have more prejudicial attitudes than those entering the profession. There is a significant negative relationship between prejudice and helping behaviour for qualified healthcare professionals.

Conclusions: Increased prejudicial attitudes of qualified staff are related to a decrease in intended helping behaviour, which has the potential to impact negatively on an individual's recovery post-injury.

"To be accepted as normal": Public understanding and misconceptions concerning survivors of brain injury.

PRIMARY OBJECTIVE: To determine the views held by the general public in Northern Ireland towards survivors of brain injury. RESEARCH DESIGN: Qualitative semi-structured interviews. METHODS AND PROCEDURES: Interviews were conducted with 16 members of the general public. Ten questions addressed issues such as the role of survivors of brain injury in society, the challenges they face and the characteristics ascribed to them. MAIN OUTCOMES AND RESULTS: When asked to describe someone with a brain injury participants typically used negative labels and identified the most common problems as relating to physical, cognitive, emotional and social functioning. There was a general failure to recognize that brain injury was a 'hidden' disability, with most participants expecting some outward manifestation. Relatively few previous studies have employed a qualitative approach to explore how the public perceives survivors of brain injury. CONCLUSION: Members of the public have an increasing awareness of the challenges faced by survivors of brain injury. However, in spite of this, perceptions of aggressiveness, dependency and unhappiness were still evident, suggesting potential problems in reintegrating survivors of brain injury with their communities.