scholarly journals Cocaine attenuates blood flow but not neuronal responses to stimulation while preserving neurovascular coupling for resting brain activity

2015 ◽  
Vol 21 (10) ◽  
pp. 1408-1416 ◽  
Author(s):  
W Chen ◽  
P Liu ◽  
N D Volkow ◽  
Y Pan ◽  
C Du
2018 ◽  
Vol 26 (4) ◽  
pp. 229-234
Author(s):  
Masaru Nakamura ◽  
Takahiko Nagamine

Neuronal activity is tightly coordinated with blood flow to ensure proper brain function. This is achieved by neurovascular coupling. Although this mechanism is maintained by numerous mediators such as nitric oxide, ion channels, and astrocytes, its signaling process is much more complex. Frontal-temporal brain activity as measured by near infrared (NIR) spectroscopy has been suggested to be decreased or disturbed in many psychiatric disorders. To investigate the relationship between serum electrolyte levels and prefrontal hemodynamic responses, we evaluated psychiatric patients who underwent NIR spectroscopy with a 22-channel topography system and measurement of serum electrolyte levels. Changes in the concentration of oxygenated hemoglobin were evaluated during a verbal fluency test. The data were analyzed to see any significant correlation between NIR spectroscopy indices (integral value: size of an area during activation, centroid value: centroid time of an area throughout the task, and initial value: axis assessed by an initial change) and serum electrolyte levels (sodium, potassium, and chloride) by gender and cortex region. The study population consisted of 102 males (mean age, 42.4 years) and 133 females (mean age, 47.2 years). Sodium levels were significantly positively correlated with integral values at temporal regions in female subjects, while potassium levels were significantly negatively correlated with initial values at frontal regions in male subjects. However, chloride levels showed no correlations. In conclusion, higher serum sodium levels increase and higher serum potassium levels decrease regional cerebral blood flow with gender variances in psychiatry. The effect of extracellular electrolyte concentrations on hemodynamic responses remains unverified. However, our findings suggest that serum electrolytes levels may be involved in vascular smooth muscle contractility via Na+-K+-ATPase pumps that mediate neurovascular coupling.


2007 ◽  
Vol 7 (4) ◽  
pp. 91-94 ◽  
Author(s):  
Theodore H. Schwartz

Hemodynamic surrogates of epileptic activity are being used to map epileptic foci with PET, SPECT, and fMRI. However, there are few studies of neurovascular coupling in epilepsy. Recent data indicate that cerebral blood flow, although focally increased at the onset of a seizure, may be temporarily inadequate to meet the metabolic demands of both interictal and ictal epileptic events. Transient focal tissue hypoxia and hyperperfusion may be excellent markers for the epileptic focus and may even precede the onset of the ictal event.


2021 ◽  
Author(s):  
Maria Sancho ◽  
Nicholas R. Klug ◽  
Amreen Mughal ◽  
Thomas J. Heppner ◽  
David Hill-Eubanks ◽  
...  

SUMMARYThe dense network of capillaries composed of capillary endothelial cells (cECs) and pericytes lies in close proximity to all neurons, ideally positioning it to sense neuro/glial-derived compounds that regulate regional and global cerebral perfusion. The membrane potential (VM) of vascular cells serves as the essential output in this scenario, linking brain activity to vascular function. The ATP-sensitive K+ channel (KATP) is a key regulator of vascular VM in other beds, but whether brain capillaries possess functional KATP channels remains unknown. Here, we demonstrate that brain capillary ECs and pericytes express KATP channels that robustly control VM. We further show that the endogenous mediator adenosine acts through A2A receptors and the Gs/cAMP/PKA pathway to activate capillary KATP channels. Moreover, KATP channel stimulation in vivo causes vasodilation and increases cerebral blood flow (CBF). These findings establish the presence of KATP channels in cECs and pericytes and suggest their significant influence on CBF.HIGHLIGHTSCapillary network cellular components—endothelial cells and pericytes—possess functional KATP channels.Activation of KATP channels causes profound hyperpolarization of capillary cell membranes.Capillary KATP channels are activated by exogenous adenosine via A2A receptors and cAMP-dependent protein kinase.KATP channel activation by adenosine or synthetic openers increases cerebral blood flow.


2012 ◽  
Vol 32 (7) ◽  
pp. 1277-1309 ◽  
Author(s):  
Andy Y Shih ◽  
Jonathan D Driscoll ◽  
Patrick J Drew ◽  
Nozomi Nishimura ◽  
Chris B Schaffer ◽  
...  

The cerebral vascular system services the constant demand for energy during neuronal activity in the brain. Attempts to delineate the logic of neurovascular coupling have been greatly aided by the advent of two-photon laser scanning microscopy to image both blood flow and the activity of individual cells below the surface of the brain. Here we provide a technical guide to imaging cerebral blood flow in rodents. We describe in detail the surgical procedures required to generate cranial windows for optical access to the cortex of both rats and mice and the use of two-photon microscopy to accurately measure blood flow in individual cortical vessels concurrent with local cellular activity. We further provide examples on how these techniques can be applied to the study of local blood flow regulation and vascular pathologies such as small-scale stroke.


2011 ◽  
Vol 26 (S2) ◽  
pp. 425-425
Author(s):  
M. Kubo

ObjectivesWe measured mayer wave in the prefrontal cortex during the performance of original version TMT by multichannel NIRS using sensitive for detecting changes of oxyHb.MethodsSixteen healthy student volunteers performed four different screens of TMT-A, and then two different screens of TMT-B.ResultsMayer wave changed while in the prefrontal cortex during the performance of TMT-A and TMT-B. The changes were prominent during the TMT performed. Mayer wave changed in the rear prefrontal cortex during TMT.Additional measurements and to present a detailed database.ConclusionMeyer wave reflects brain activity. You should consider in more detail.


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