Tritium-labelled morphine sulphate was injected into the lumbar (L4-5) subarachnoid space of an adult male baboon. Three hours after injection, the animal was sacrificed. Using quantitative light microscopic autoradiographic mapping techniques, contour and perspective diagrams were prepared that described the position of radiolabel and by inference the distribution of morphine binding sites within the spinal cord. High concentrations of 3 H was found in the medial regions of laminae I, II (substantia gelatinosa) and III of the dorsal horns. Smaller, but significant levels were seen bilaterally in the spinal anterolateral quadrant. Minimal 3 H activity was seen in the remainder of the spinal cord with the lowest level being recorded in the spinal canal. Perspective graphics proved a precise and attractive method for locating the position and quantifying the concentration of radio la bel in baboon spinal cord.
OMICS International Commentary
AbstractThis commentary considers the implications of the findings related to the effect of a community-based, multiple modality and dual-task exercise training program in the Archives of Gerontology and Geriatrics. Findings from this study suggest that participants who performed the multiple modality and dual-task exercise intervention experienced greater improvements in global cognition, greater elevations in dual-task gait speed and dual-task step-length and greater reductions in dual-task stride time variability when compared to participants who did not perform the dual-task component of the exercise training program. The ability of exercise to impart cognitive and other physiological benefits has been long understood; however, the mechanisms that facilitate these training-induced improvements remain elusive. Mediation analyses provide a unique avenue to investigate the relationship between various physiological measures and can provide insight related to the causal sequence that drives the beneficial physiological and psychological response to an intervention. Recent works have incorporated mediation analyses within their study designs and the insight provided therein has revealed a number of intriguing intricacies with respect to cognition in aging and the effect of exercise on the body and brain. Mediation analyses are rarely utilized in neurophysiological research; however, the complex phenomenological relationships that can be revealed using this method will be crucially required for the identification of factors responsible for improvements in cognition following pharmacological or lifestyle-based interventions, and the development of effective management strategies for older adults with cognitive impairment. This commentary considers the implications of the findings related to the effect of a community-based, multiple modality and dual-task exercise training program previously described by Gregory et al. [1] in the Archives of Gerontology and Geriatrics. The authors report that participants who performed the multiple modality and dual-task exercise intervention experienced greater elevations in dual-task gait speed and dual-task step-length and reductions in dual-task stride time variability when compared to participants who did not perform the dualtask component of the exercise training program. These results were secondary to the primary analysis concerning change in cognition postexercise training [2], which suggested that participants performing the multiple modality and dual-task exercise training program experienced greater elevations in global cognitive functioning when compared to those who performed the multiple modality exercise program alone; these improvements were driven by improvements in verbal learning and memory and verbal fluency scores.
Commentary on "Group-BasedAlthough this study was a well-designed randomized controlled trial (RCT) that collected a number of physiological, psychological and behavioural outcomes, the primary limitation to the interpr...
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