Objective: The aim of the study was to determine role nebulized dexmedetomidine in attenuating stress response laryngoscopy and intubation observe any adverse effects drug such as cough, bradycardia, hypotension, dose-sparing result propofol. Methods: A prospective observational conducted a tertiary care teaching hospital for 12 months. total 62 patients (ASA 1 2) age group 18–65 years schedule...

An important constraint on how hemodynamic neuroimaging signals such as fMRI can be interpreted in terms of the underlying evoked activity is an understanding of neurovascular coupling mechanisms that actually generate hemodynamic responses. The predominant view at present is that the hemodynamic response is most correlated with synaptic input and subsequent neural processing rather than spikin...

conclusions blood glucose and hemodynamic changes caused by surgical stress were not significantly different between two groups. results there was not significantly difference between blood glucose level of both groups during 10 minutes before, 20 and 60 minutes after the intiation of anesthesia. heart rate changes in the general and spinal groups compared to the baseline level were decreased u...

Today, most studies of cognitive processes using functional magnetic resonance imaging (fMRI) adopt an event-related experimental design. Highly flexible stimulation settings require new statistical models where not only the activation amount, but also the time course of the measured hemodynamic response is analyzed. It is possible to obtain statistically valid descriptions of single hemodynami...

An understanding of the relationship between changes in neural activity and the accompanying hemodynamic response is crucial for accurate interpretation of functional brain imaging data and in particular the blood oxygen level-dependent (BOLD) fMRI signal. Much physiological research investigating this topic uses anesthetized animal preparations, and yet, the effects of anesthesia upon the neur...

While a range of cellular mechanisms have been proposed to underlie control of neurovascular coupling, a comprehensive, reconciliatory model has yet to be determined. To fit with such a model, it is essential that candidate mechanisms exhibit reaction times, spatial ranges, and speeds of propagation that are consistent with the vascular manifestations of the 'hemodynamic response'. Understandin...

Functional imaging methods monitor neural activity by measuring hemodynamic signals. These are more closely related to local field potentials (LFPs) than to action potentials. We simultaneously recorded electrical and hemodynamic responses in the cat visual cortex. Increasing stimulus strength enhanced spiking activity, high-frequency LFP oscillations, and hemodynamic responses. With constant s...

Objective-  To evaluate kidney hemodynamic response including blood flow velocity in segmental arteries shortly after administration of various dose of saffron extract (10, 40 and 90 mg/kg).   Design- Technical assessment, experimental study.   Animals- 20 healthy male Sprague-Dawley rats.   Procedures- In this study, using a real-time pulsed doppler analysis, kidney hemodynamic response inc...

Measuring brain activity in developmental populations remains a major challenge despite great technological advances. Among the numerous available methods, functional near-infrared spectroscopy (fNIRS), an imaging modality that probes the hemodynamic response, is a powerful tool for recording brain activity in a great variety of situations and populations. Neurocognitive studies with infants ha...

We highlight a significant problem that needs to be considered and addressed when performing functional near-infrared spectroscopy (fNIRS) studies, namely the possibility of inadvertently measuring fNIRS hemodynamic responses that are not due to neurovascular coupling. These can be misinterpreted as brain activity, i.e., "false positives" (errors caused by wrongly assigning a detected hemodynam...