Understanding neurovascular coupling is a prerequisite for the interpretation of results obtained from modern neuroimaging techniques. This study investigated the hemodynamic and neural responses in rat somatosensory cortex elicited by 16 seconds electrical whisker stimuli. Hemodynamics were measured by optical imaging spectroscopy and neural activity by multichannel electrophysiology. Previous...

OBJECTIVE Women exhibit exaggerated renal hemodynamic responses to hyperglycemia, which may promote kidney disease progression. Our aim was to determine if increased nitric oxide generation by l-arginine infusion would reverse this deleterious response to clamped hyperglycemia in women with type 1 diabetes mellitus. RESEARCH DESIGN AND METHODS Renal function, blood pressure, and plasma cyclic...

asthma management is a major concern because some asthmatic patients either do not respond or else hardly respond to treatment. therefore in the present study, an attempt has been made to determine the predictors of treatment response in asthmatic patients. thirty six asthmatic adults including 13 male and 23 female were studied dur¬ing a 3 month treatment period. asthma symptom score (ss) and ...

The goal of many functional Magnetic Resonance Imaging (fMRI) studies is to infer neural activity from hemodynamic signals. Classical fMRI analysis approaches assume that the hemodynamic response function (HRF) is identical in every voxel, i.e. it is separable in voxel-space and time. This study demonstrates to our knowledge for the first time directly that although the nonseparable part is sma...

The aim of this study was to examine the relative contribution of both cyclooxygenase (COX) isoforms in producing the prostaglandins (PG) involved in the regulation of renal function, when nitric oxide (NO) synthesis is reduced. In anesthetized dogs with reduction of NO synthesis, the renal effects of a nonisozyme-specific COX inhibitor (meclofenamate) were compared with those elicited by a sel...

The noninvasive mapping of hemodynamic brain activity has led to significant advances in neuroimaging. This approach is based in part on the assumption that hemodynamic changes are proportional to (and therefore constitute a linear measure of) neuronal activity. We report a study investigating the quantitative relationship between neuronal and hemodynamic measures. This study exploited the fact...

We investigated the effects of paired presentations of visual stimuli upon the evoked hemodynamic response of visual cortex measured by magnetic resonance imaging (MRI). Stimuli were identical 500-ms high-contrast checkerboard patterns, presented singly or with an interpair interval (IPI) of 1, 2, 4, or 6 s (onset-to-onset), followed by an intertrial interval of 16-20 s. Images were acquired at...