The zona incerta (ZI) is a subthalamic nucleus connected to several structures, some of them known to be involved with antinociception. The ZI itself may be involved with both antinociception and nociception. The antinociceptive effects of stimulating the ZI with glutamate using the rat tail-flick test and a rat model of incision pain were examined. The effects of intraperitoneal antagonists of acetylcholine, noradrenaline, serotonin, dopamine, or opioids on glutamate-induced antinociception from the ZI in the tail-flick test were also evaluated. The injection of glutamate (7 μg/0.25 μl) into the ZI increased tail-flick latency and inhibited post-incision pain, but did not change the animal performance in a Rota-rod test. The injection of glutamate into sites near the ZI was non effective. The glutamate-induced antinociception from the ZI did not occur in animals with bilateral lesion of the dorsolateral funiculus, or in rats treated intraperitoneally with naloxone (1 and 2 m/kg), methysergide (1 and 2 m/kg) or phenoxybenzamine (2 m/kg), but remained unchanged in rats treated with atropine, mecamylamine, or haloperidol (all given at doses of 1 and 2 m/kg). We conclude that the antinociceptive effect evoked from the ZI is not due to a reduced motor performance, is likely to result from the activation of a pain-inhibitory mechanism that descends to the spinal cord via the dorsolateral funiculus, and involves at least opioid, serotonergic and α-adrenergic mechanisms. This profile resembles the reported effects of these antagonists on the antinociception caused by stimulating the periaqueductal gray or the pedunculopontine tegmental nucleus.

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Introduction and aim. Arterial stiffness (AS) has been associated with reduced cardiorespiratory fitness (CRF). The aim of this study was to verify if there is a relationship between augmentations index (AIx), as an index for AS assessment, and CRF in individuals with type 2 Diabetes Mellitus (T2DM). Material and methods. Observational cross-sectional study including 32 individuals diagnosed with T2DM who performed two evaluations: 1. Arterial stiffness assessment using SphygmoCor and 2. CRF throughout a cardiopulmonary exercise test on a treadmill ergometer. Oxycon Mobile® device was used to obtain oxygen uptake consumption at peak (V˙ O2peak); oxygen uptake efficiency slope (OUES) determined by linear regression in reason of the logarithmic transformation of the ventilation and V˙ O2 obtained every minute of exercise test. Statistical analysis comprised Pearson’s Correlation and linear regression analysis performed in SigmaPlot. Results. There was a significant correlation between AS and CRF: AIx and OUES; AIx@75 and; OUES. In linear regression, AIx was determinant for V˙ O2peak and OUES – AIx and; AIx@75 and V˙ O2peak. Conclusion. AS was associated with CRF in individuals with T2DM. These results contribute to the body of evidence linking arterial functional properties to CRF and suggests greater attention for this important index.

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Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): São Paulo Research Foundation (FAPESP);Coordination for the Improvement of Higher Education Personnel (CAPES) Background Higher activity levels are linked with better cardiovascular health. Maximum aerobic power (measured by the maximal oxygen uptake, VO2max) obtained during cardiopulmonary exercise testing (CPET) is an index of cardiovascular health and represents the maximum ability of the aerobic system to supply energy. Moreover, it is known that high-intensity activities of daily living (hiADL) are associated with higher VO2max, and were three times more beneficial than low-intensity activities, such as light walking. However, little is known about the physiological responses during these hiADL that are associated with better health outcomes. So far, only the levels and intensities of the physical activities have been investigated, but the physiological responses at these activities remain unclear. Purpose Verify the associations between VO2max and longitudinal vital signals from wearables during hiADL. Methods 43 volunteers (32 males, 39.91±15.87 years; 75.41±13.12 kg; 173.67±9.04 cm) with different levels of VO2max (31.08±8.73 ml/kg/min) wore a wearable device (smart t-shirt, Hexoskin) with embedded cardiac, respiratory, and movement sensors to collect unobtrusive data for 7 days (9.31±1.36 hours per day). These sensors continuously measure heart rate (HR), breathing rate (BR), minute ventilation (VE), tidal volume (Vt), hip acceleration (ACC), and walking cadence (Cad). The hiADL were classified based on the Cad response where values higher than 124 steps per minute were labelled as hiADL. At hiADL, the average response for all variables was calculated. Finally, the Pearson or Spearman correlations were computed considering a statistical significance level of 5%. Results hiADL corresponded to just 1% of the physical activities (or 35.11±43.30 minutes per week). The average response of the vital signals at hiADL were: HR (118.2±20.36 bpm), BR (30.7±8.0 rpm), VE (52.21±35.54l), Vt (1.63±0.71 l/min), Acc (0.87±0.6g), and Cad (143.69±10.13). The correlations were statistically (p<0.05) high and positive between VO2max and BR, VE, Vt, and Cad; also, moderate, and positive between VO2max and HR and with the percentage of the time spent at hiADL, as described in figure 1. Conclusion The VO2max (or cardiovascular health) is related to the time spent in hiADL and with the hemodynamic and respiratory response magnitudes at these high-intensity activities.