Associations between serum cortisol, cardiovascular function and neurological outcome following acute global hypoxia in the newborn piglet

Perinatal asphyxia is a significant contributor to neonatal brain injury. However, there is significant variability in neurological outcome in neonates after global hypoxiaischemia. The aims of this study were to identify which physiological response/s during global hypoxiaischemia influence the severity of brain injury and to assess their relative importance. Hypoxia/hypercapnia was induced in 20 anaesthetized piglets by reducing the inspired oxygen fraction to 10% and the ventilation rate from 30 to 10 breaths per minute for 45 min. Neurological outcome was assessed using functional markers including cerebral function amplitude (via electroencephalography) and cerebral impedance, and the structural marker microtubule associated protein-2 by immunohistochemistry at 6 h post hypoxia. Significant variability in neurological outcome was observed following the constant hypoxia/hypercapnia insult. There was a high degree of variability in cardiovascular function (mean arterial blood pressure and heart rate) and serum cortisol concentrations in response to hypoxia. More effective maintenance of cardiovascular function and higher serum cortisol concentrations were associated with a better outcome. These two variables were strongly associated with neurological outcome, and together explained 68% of the variation in the severity of neurological outcome. The variability in the cardiovascular and cortisol responses to hypoxia may be a more important determinant of neurological outcome then previously recognized

Omega-3 polyunsaturated fatty acids and brain health: Preclinical evidence for the prevention of neurodegenerative diseases

Background As the prevalence of neurodegenerative diseases increases steadily, the need to develop new treatment approaches intensifies and the possibility of targeting risk and protective factors to delay onset of these diseases is attracting more interest. Dietary habits stand as one of the most promising modifiable risk factors for both Alzheimer's (AD) and Parkinson's (PD) diseases. Scope and approach Over the last 30 years, several groups have generated data indicating that concentrations of specific brain lipids highly depend on dietary intake. Preclinical results show that treatments with omega-3 polyunsaturated fatty acids (n-3 PUFA) improve cognition, provide neuroprotection (and even neurorestoration), reduce neuroinflammation and influence neuronal function, while high-fat diets exert deleterious effects. Preclinical experiments have been conducted in well-recognized animal models of AD, PD, and ischemic stroke. Key findings and conclusions These studies have shown that dietary n-3 PUFA treatments consistently improve cognitive performance in animal models and may also exert disease-modifying actions. N-3 PUFA also provide protection to dopaminergic neurons in animal models of PD and possibly recovery after lesion. Furthermore, some of these effects might depend on specific diet formulations to protect long-chain fatty acids from oxidation or synergies with other nutrients. More generally, this review aims at providing evidence that adjustments in the consumption of dietary lipids alone or combined with other nutrients may be a cost-effective intervention to optimize brain function and prevent AD or PD