Cerebrovascular Adaptation in Chronic Hydrocephalus

Luciano, Mark; Skarupa, David; Booth, Amy M.; Wood, Arcangela S.; Brant, Christine L; Gdowski, Martha Johnson

doi:10.1097/00004647-200103000-00012

Cited by 52 publications

(41 citation statements)

References 23 publications

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“…29,30 In conclusion, in the present descriptive study, we showed a correlation of both the short-term and the long-term neuronal responses with a moderate but prolonged reduction of CBF that was demonstrated during the first weeks after hydrocephalus induction.…”

Section: Cbf Changes and Neuronal Responsessupporting

confidence: 66%

Cerebral Hypoperfusion and Delayed Hippocampal Response After Induction of Adult Kaolin Hydrocephalus

Klinge

Samii

Mühlendyck

et al. 2003

Stroke

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Background and Purpose-In chronic hydrocephalus, a role for tissue hypoxia resulting from cerebrovascular compression is suggested. The purpose of this study was to evaluate whether changes in cerebral blood flow (CBF) in the time course of adult kaolin-induced hydrocephalus correlated with immunohistochemical neuronal responses. Methods-In 46 adult Sprague-Dawley rats, kaolin hydrocephalus was induced and immunostaining of neurofilament protein (NF68), synaptophysin (SYN38), and neuronal nitric oxide synthase (NOS) was performed at 2 (short term), 4 (intermediate term), and 6 and 8 (long term) weeks. Local CBF was measured quantitatively by [ 14 C]iodoantipyrine ([ 14 C]IAP) autoradiography in the short-term stage and in both long-term stages. Results-At 2 weeks, neuronal NOS immunoreactivity was globally increased in cortical areas and within the hippocampus. Four weeks after hydrocephalus induction, a reactive increase of SYN38 and NF68 immunoreactivity in the periventricular cortex was seen. At 6 and 8 weeks, when the ventricular size was decreasing, immunohistochemical changes in the hippocampus became most evident. A maintained toxic NOS reactivity in the CA1 subfield was accompanied by a loss of NF68 staining. In the CA3 subfield, however, focal increases in NF68 and SYN38 immunoreactivity were found. Cortical and hippocampal blood flow showed prolonged decreases of 25% to 55% compared with control animals. At 8 weeks, control levels were reached. Conclusions-The observed temporary CBF decrease appears to correlate with an early global neuronal ischemic response.In addition, it may also account for the delayed selective response of ischemia-vulnerable structures, eg, hippocampus, in chronic adult kaolin-induced hydrocephalus.

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Section: Cbf Changes and Neuronal Responsessupporting

confidence: 66%

Cerebral Hypoperfusion and Delayed Hippocampal Response After Induction of Adult Kaolin Hydrocephalus

Klinge

Samii

Mühlendyck

et al. 2003

Stroke

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“…CBF data were collected from different sources: for mouse [70], rat [71], rabbit [72], cynomolgus monkey [73], rhesus monkey [74], pig [75], and human [76]. Cerebral capillary characteristics were obtained from several sources: for mouse [14], [51], rat [15], [77], [32], cat [40], [78], dog [79], rhesus monkey [80], and human [33], [34]. Data for calculating neuron densities were taken from [24], [25], [41], [52], [81], [82].…”

Section: Methodsmentioning

confidence: 99%

Scaling of Brain Metabolism and Blood Flow in Relation to Capillary and Neural Scaling

Karbowski

2011

PLoS ONE

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Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 relating whole body resting metabolism with body mass and several other physiological variables in animals and plants. This article investigates the reasons for brain allometric distinction on a level of its microvessels. Based on collected empirical data it is found that regional cerebral blood flow CBF across gray matter scales with cortical volume as , brain capillary diameter increases as , and density of capillary length decreases as . It is predicted that velocity of capillary blood is almost invariant (), capillary transit time scales as , capillary length increases as , and capillary number as , where is typically a small correction for medium and large brains, due to blood viscosity dependence on capillary radius. It is shown that the amount of capillary length and blood flow per cortical neuron are essentially conserved across mammals. These results indicate that geometry and dynamics of global neuro-vascular coupling have a proportionate character. Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.

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“…Percentage staining was defined as the percent area occupied by black pixels. GFAP immunoreactivity and number of GFAP-ir fibers were assessed in the external zone of the ME using images photographed at 63× magnification [20]. Analysis was carried out by placing a 0.013 mm 2 square along the center of the left and right bulbs of the ME.…”

Section: Methodsmentioning

confidence: 99%

Effects of photoperiod and food restriction on the reproductive physiology of female California mice

Steinman

Knight

Trainor

2012

General and Comparative Endocrinology

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Many temperate-zone animals use changes in photoperiod to time breeding. Shorter term cues, like food availability, are integrated with photoperiod to adjust reproductive timing under unexpected conditions. Many mice of the genus Peromyscus breed in the summer. California mice (Peromyscus californicus), however, can breed year round, but tend to begin breeding in the winter. Glial cells may be involved in transduction of environmental signals that regulate gonadotrophin releasing hormone (GnRH) activity. We examined the effects of diet and photoperiod on reproduction in female California mice. Mice placed on either short days (8L:16D) or long days (16L:8D) were food restricted (80% of normal intake) or fed ad libitum. Short day-food restricted mice showed significant regression of the reproductive system. GnRH-immunoreactivity was increased in the tuberal hypothalamus of long day-food restricted mice. This may be associated with the sparing effect long days have when mice are food restricted. The number of GFAP-immunoreactive fibers in proximity to GnRH nerve terminals correlated negatively with uterine size in ad libitum but not food restricted mice, suggesting diet may alter glial regulation of the reproductive axis. There was a trend towards food restriction increasing uterine expression of c-fos mRNA, an estrogen dependent gene. Similar to other seasonally breeding rodents, short days render the reproductive system of female California mice more susceptible to effects of food restriction. This may be vestigial, or it may have evolved to mitigate consequences of unexpectedly poor winter food supplies.

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Cerebrovascular Adaptation in Chronic Hydrocephalus

Cited by 52 publications

References 23 publications

Cerebral Hypoperfusion and Delayed Hippocampal Response After Induction of Adult Kaolin Hydrocephalus

Cerebral Hypoperfusion and Delayed Hippocampal Response After Induction of Adult Kaolin Hydrocephalus

Scaling of Brain Metabolism and Blood Flow in Relation to Capillary and Neural Scaling

Effects of photoperiod and food restriction on the reproductive physiology of female California mice

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