Abelhjorth5761

Cerebral capillaries respond to changes in neural activity to maintain regional balances between energy demand and supply. However, the quantitative aspects of the capillary diameter responses and their contribution to oxygen supply to tissue remain incompletely understood. The purpose of the present study is to check if the diameters measured from large-scale angiographic image data of two-photon laser scanning fluorescent microscopy (2PLSM) are correctly determined with a custom-written MATLAB software and to investigate how the measurement errors can be reduced, such as at the junction areas of capillaries. As a result, nearly 17% of the measured locations appeared to be outliers of the automated diameter measurements, in particular arising from the junction areas where three capillary segments merged. selleck inhibitor We observed that about two-thirds of the outliers originated from the measured locations within 6 μm from the branching point. The results indicate that the capillary locations in the junction areas cause non-negligible errors in the automated diameter measurements. Considering the common site of the outliers, the present study identified that the areas within 6 μm from the branch point could be separately measured from the diameter analysis, and careful manual inspection with reference to the original images for these transition areas around the branch point is further recommended.The aim was to evaluate the changes in brain tissue oxygenation, assessed by near-infrared spectroscopy (NIRS), during transcranial alternating current stimulation (tACS) in patients with mild and moderate traumatic brain injury (TBI). Nineteen patients with diffuse, blunt, non-severe TBI (mean age 32.7 ± 11.4 years; 4 women and 15 men; Glasgow Coma Score before tACS 14.1 ± 0.5) were treated by 10 Hz in-phase tACS applied for 30 minutes to the left and right lateral prefrontal cortex at 21 days after TBI. Regional cerebral tissue oxygen saturation (SctO2) in the frontal lobes was measured simultaneously by the cerebral oximeter. Significance was preset to P 0.05). Therefore, tACS causes a significant decrease in SctO2, probably, due to neuronal activation. Our data indicate that tACS may need to be supplemented with oxygen therapy. Further research is required.Sleep apnea syndrome (SAS) often accompanies alterations in heart rate variability (HRV). The severity of SAS is sometimes evaluated using the oxygen desaturation index (ODI). We hypothesized that effects of the autonomic nervous system could be involved in the coordination between HRV and physical acceleration during free movement in patients with SAS. Among 33 women aged 60 years or older, 19 had a high ODI (>5). Their HRV and physical acceleration were simultaneously obtained every minute for 24 hours. The low frequency/high frequency (LF/HF) ratio and the high frequency in normalized units (HFnu) were used as HRV indices. Low levels of %Lag0, defined as the percentage of the lag = 0 min in 1 h, indicated coordination between physical acceleration and HRV. Nineteen participants were divided into group A (high %Lag0 before sleep [n = 9]) or group B (low %Lag0 [n = 10]). In group B participants with a high ODI and low %Lag0 in the hour after waking, HFnu was significantly increased compared to that in group A participants with high ODI and high %Lag0 in the hour after waking (p less then 0.05). These results suggest that close associations between high ODI and discoordination between HRV and physical acceleration may be due to higher parasympathetic nervous system activity after waking.Autonomic disorders such as orthostatic hypotension often become a problem during the early mobilization of poststroke patients. We reported that the prefrontal cortex (PFC) oxyhemoglobin changes at rest are often on the right, and a positive correlation was observed between the left and right activity balance and the change in oxy-Hb. In this study, we focused on the asymmetrical changes associated with the standing load from rest. We assessed the left-right asymmetry of the PFC oxyhemoglobin changes at rest and standing load by calculating the Laterality Index at Rest (LIR) and laterality index during activity (LIA); positive values indicate the right-dominant activity, while negative values indicate left-dominant activity. As for left-right asymmetry LIA, the active dominant PFC was reversed in five patients. It should be noted that in almost all of the 13 cases, the active PFC and the lesion side matched. The detailed mechanism of overactivity up to the prefrontal cortex on the lesion side is unknown, but it may be a recovery mechanism that elicits plasticity in the brain network.

In modern society, we are increasingly exposed to numerous sources of blue light, including screens (e.g., TVs, computers, laptops, smartphones, tablets) and light from fluorescent and LED lamps. Due to this wide range of applications, the effects of blue light exposure (BLE) on the human physiology need to be thoroughly studied.

To investigate the impact of long-term BLE on frontal and occipital human cerebral hemodynamics and oxygenation using functional near-infrared spectroscopy (fNIRS) neuroimaging.

32 healthy right-handed subjects (20 females, 12 males; age 23.8±2.2years) were exposed to blue LED light for 15minutes. Before (baseline, 8min) and after (recovery, 10min) the BLE, subjects were in darkness. We measured the concentration changes of oxyhemoglobin ([O

Hb]) and deoxyhemoglobin ([HHb]) at the prefrontal cortex (PFC) and visual cortex (VC) by fNIRS during the experiment. Subjects were then classified into different groups based on their hemodynamic response pattern of [O

Hb] at the PFC an to their magnitudes and shapes, and (iii) can be classified into eight groups. We conclude that blue light affects humans differently. It is essential to consider this when assessing the impact of the BLE on society.Normal brain function requires an integrated, simultaneous communication between brain regions in a coordinated manner. In our studies on cortical spreading depolarization (CSD) induced electrically in the rat brain while recording electrocorticography (ECoG) and delta wave activity, we found for the first time that CSD suppressed delta wave activity, which began even before the CSD was fully developed. We pursued this observation to determine whether repeated CSD suppressed delta wave activity in rats. CSD was produced by electrical stimulation of the neocortex while recording the development of CSD and changes in the coupling of low-frequency band cross coupling to four typical physiological neuronal activity frequency bands, i.e., 5-7 Hz, 8-12 Hz, 13-30 Hz, and 30-80 Hz. Band-pass filters were applied to achieve the corresponding physiological band signals. Besides the cross-frequency coupling (CFC) analysis, the distribution of delta wave density in time domain was analyzed. We calculated the delta wave density per 30 seconds but represent the density as frequency per minute.