Hyperglycemic diet and training alter insulin sensitivity, intramyocellular lipid content but not UCP3 protein expression in rat skeletal muscles

Intramyocellular lipids (IMCL) and mitochondrial uncoupling protein-3 (UCP3) have been implicated in the development of muscular insulin resistance. This study aimed to investigate the role of IMCL and UCP3 in the development of glucose intolerance and muscular insulin resistance during 12 weeks of an obesity-inducing 'cafeteria-style' diet alone (CAF), or in conjunction with exercise training from weeks 8-12 (CAFTR), in rats. At the end of the intervention period, gain in body weight was 20% higher in CAF (305+/-10 g) than controls (CON) (255+/-14 g; p<0.001) and CAFTR (253+/-7 g; p<0.001). Furthermore, compared with CON, the Matsuda insulin sensitivity index (ISI), assessed during a 2-h intravenous glucose tolerance test, was markedly lower in CAF (6.7+/-0.4) than in either CON (15.6+/-1.4; p<0.001) or CAFTR (11.2+/-1.1; p<0.001). Moreover, in CAF glucose transport at a submaximal insulin concentration (200 microU/ml) was reduced by approximately 60% (p<0.05) in both red and white gastrocnemius muscles, but not in m. soleus. However, glucose transport in CAFTR was similar to CON in red gastrocnemius. In CAF fiber-specific IMCL content determined in m. soleus and extensor digitorum longus (EDL), was higher than in CON (p<0.01) and CAFTR (p<0.001). Muscle UCP3 protein content was not changed by any of the interventions. Interestingly, within CAF and CAFTR, ISI closely negatively correlated with IMCL content in both type I (soleus, r=-0.93; EDL, r=-0.90; p<0.05) and IIa (EDL, r=-0.52, p<0.05) muscle fibers. These findings indicate that changes in IMCL content but not UCP3 content are implicated in short-term effects of cafeteria-style diet and exercise training on muscular insulin sensitivity in rats

Looking under the bonnet of conservation conflicts: can neuroscience help?

Neuroscience—a branch of biology seemingly distant from nature/wildlife conservation is revolutionised by the ability to visualise the brain activity of humans. Using positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and magnetoencephalograhy (MEG), neuroscience is revealing how humans are wired in ways that have bearing on any problem that involves values; and nature/wildlife conservation is surely one of those. Understanding how the human brain represents and processes morality and sacred values, and responds to conflicts could shed a powerful light on nature/wildlife conservation tactics. Conservation polices typically involve utilitarian considerations. However, research shows that conservation policies based solely on utilitarian considerations are likely to fail as the neurological process of rights and wrongs grates against the process of cost and benefits