The relationship of age and hypertension with cognition and gray matter cerebral blood volume in a rhesus monkey model of human aging.

2021 ◽  
Author(s):  
Chad W. Farris ◽  
Ronald J. Killiany ◽  
Elizabeth O'Donoghue ◽  
Bang-Bon Koo ◽  
Richard D. Wainford ◽  
...  
1990 ◽  
Vol 259 (3) ◽  
pp. H674-H680 ◽  
Author(s):  
A. A. Shoukas ◽  
H. G. Bohlen

The hypothesis that the pressure-diameter relationship of intestinal venules in rats is primarily determined by sympathetic nervous system activity was tested. The pressure-diameter relationship of the smallest to largest diameter (20-100 microns) intestinal venules of the rat was measured at rest, during hemorrhage to increase sympathetic neural activity, and during saline volume expansion to decrease sympathetic activity. During hemorrhage, the diameter of all venules decreased approximately 10% at 10 mmHg venous pressure, and the slope of the pressure-diameter relationship increased approximately 50% above control. Blood volume expansion led to an approximately 10% increase in venule diameter at 10 mmHg and a 25% decrease in slope. Denervation of the vessels causes concomitant vasodilation, which was greater than the vasodilation caused by blood volume expansion. Hemorrhage after denervation caused no significant changes in the relationship when compared with denervated control. Nitroprusside caused an even greater vasodilation when compared with the pressure-diameter relationship after denervation. The results suggest that the slope and 10-mmHg intercept of the pressure-diameter relationship for the largest through smallest intestinal venules and, therefore, their vascular compliance and capacitance characteristics are primarily determined by sympathetic activity.


2000 ◽  
Vol 6 (7) ◽  
pp. 781-788 ◽  
Author(s):  
JENNIFER SALTZMAN ◽  
ESTHER STRAUSS ◽  
MICHAEL HUNTER ◽  
SARAH ARCHIBALD

Although the majority of research in theory of mind (TOM) has focused on young children or individuals with autism, recent investigations have begun to look at TOM throughout the lifespan and in other neurological and psychiatric populations. Some have suggested that TOM may represent a dissociable, modular brain system that is related to, but separable, from other brain functions including executive functions (EF). Recently, studies have shown that TOM performance can be compromised following an acquired brain insult (e.g, damage to the right hemisphere). However, the relationship of such impaired TOM performance to other brain functions in these cases has not been explored. This study investigated the effects of both normal human aging and Parkinson's disease on TOM. The relationship of TOM performance and EF in these groups was also examined. The results suggested that although TOM performance appeared compromised in the group of individuals with Parkinson's disease, the elderly control participants were relatively unimpaired relative to younger individuals. Significant relationships between several measures of TOM and EF were also found. The implications of these findings, and also the finding that failure on one measure of TOM did not necessarily predict failure on all measures of TOM, are discussed. (JINS, 2000, 6, 781–788.)


1959 ◽  
Vol 197 (2) ◽  
pp. 399-402 ◽  
Author(s):  
Julius J. Friedman

The effect of Nembutal on the circulating and tissue blood volumes and hematocrits was calculated by means of independent determinations of plasma and red cell volumes. Nembutal produced an increase in circulating blood volume accompanied by a reduction in the venous hematocrit. The blood volumes of liver, kidney, spleen and intestine rose following the administration of Nembutal, while the hematocrits of liver, lung, intestine and muscle declined, and that of kidney rose. The administration of Nembutal to splenectomized mice produces similar changes. The relationship of these alterations to changes in periphero-vascular tone are discussed.


2015 ◽  
Vol 43 (4) ◽  
pp. 981-989 ◽  
Author(s):  
Stephanie B. Withey ◽  
Jan Novak ◽  
Lesley MacPherson ◽  
Andrew C. Peet

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