Brain research
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Ten minutes of aerobic or resistance training can 'boost' executive function in older adults. Here, we examined whether the magnitude of the exercise benefit is influenced by exercise intensity. Older adults (N = 17: mean age = 73 years) completed a volitional test to exhaustion (VO2peak) via treadmill to determine participant-specific moderate (80% of lactate threshold (LT)), heavy (15% of the difference between LT and VO2peak) and very-heavy (50% of the difference between LT and VO2peak) exercise intensities. ⋯ Most notably, the post-exercise change in antisaccade RTs did not reliably vary with exercise intensity. Further, for each exercise intensity participants' cardiorespiratory fitness level was unrelated to the magnitude of the post-exercise executive benefit (ps > .13). Accordingly, an exercise duration as brief as 10-min provides a selective benefit to executive function in older adults across the continuum of moderate to very-heavy intensities.
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The present study aimed to investigate cerebral metabolic changes in a neuropathic pain model following deafferentation. A total of 24 Sprague-Dawley rats were included for modeling of right brachial plexus avulsion (BPA) through the posterior approach. As nerve injury would cause central sensitization and facilitate pain sensitivity in other parts of the body, thermal withdrawal latency (TWL) of the intact forepaw was assessed to investigate the level of pain perception following BPA-induced neuropathic pain. [Fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET) was applied to the brain before and after brachial plexus avulsion to explore metabolic changes in neuropathic pain following deafferentation. ⋯ Conversely, SUVs in multiple brain regions decreased, including the contralateral somatosensory cortex, ipsilateral cingulate cortex, and ipsilateral temporal association cortex. The Pearson correlation analysis showed that the SUVs of the contralateral anterodorsal hippocampus and ipsilateral dorsolateral thalamus were negatively related to the TWL of the intact forepaw, whereas the SUVs in the contralateral somatosensory cortex and ipsilateral cingulate cortex were positively related to it (p < 0.05). These findings indicate that upregulation of metabolism in the anterodorsal hippocampus and dorsolateral thalamus and downregulation metabolism in the contralateral somatosensory cortex and ipsilateral cingulate cortex could be a unique pattern of metabolic changes for neuropathic pain following brachial plexus avulsion.