Temperature and cerebrospinal fluid production rate

Snodgrass, S. Robert; Lorenzo, AV

doi:10.1152/ajplegacy.1972.222.6.1524

Cited by 30 publications

(7 citation statements)

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“…Secondly, the ability to image the entire CSF system simultaneously and sequentially gives a more complete understanding of the dynamics of CSF flow and drainage. We were able to monitor the major physiological parameters thought to influence CSF production rate, that is, ICP [58], blood pressure [59], and temperature [60]. Additionally, flow rates, whole brain volume, and CSF volume calculations were obtained from the same study.…”

Section: Discussionmentioning

confidence: 99%

Cerebrospinal fluid is drained primarily via the spinal canal and olfactory route in young and aged spontaneously hypertensive rats

Murtha

Yang

Parsons

et al. 2014

Fluids Barriers CNS

104

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BackgroundMany aspects of CSF dynamics are poorly understood due to the difficulties involved in quantification and visualization. In particular, there is debate surrounding the route of CSF drainage. Our aim was to quantify CSF flow, volume, and drainage route dynamics in vivo in young and aged spontaneously hypertensive rats (SHR) using a novel contrast-enhanced computed tomography (CT) method.MethodsICP was recorded in young (2–5 months) and aged (16 months) SHR. Contrast was administered into the lateral ventricles bilaterally and sequential CT imaging was used to visualize the entire intracranial CSF system and CSF drainage routes. A customized contrast decay software module was used to quantify CSF flow at multiple locations.ResultsICP was significantly higher in aged rats than in young rats (11.52 ± 2.36 mmHg, versus 7.04 ± 2.89 mmHg, p = 0.03). Contrast was observed throughout the entire intracranial CSF system and was seen to enter the spinal canal and cross the cribriform plate into the olfactory mucosa within 9.1 ± 6.1 and 22.2 ± 7.1 minutes, respectively. No contrast was observed adjacent to the sagittal sinus. There were no significant differences between young and aged rats in either contrast distribution times or CSF flow rates. Mean flow rates (combined young and aged) were 3.0 ± 1.5 μL/min at the cerebral aqueduct; 3.5 ± 1.4 μL/min at the 3rd ventricle; and 2.8 ± 0.9 μL/min at the 4th ventricle. Intracranial CSF volumes (and as percentage total brain volume) were 204 ± 97 μL (8.8 ± 4.3%) in the young and 275 ± 35 μL (10.8 ± 1.9%) in the aged animals (NS).ConclusionsWe have demonstrated a contrast-enhanced CT technique for measuring and visualising CSF dynamics in vivo. These results indicate substantial drainage of CSF via spinal and olfactory routes, but there was little evidence of drainage via sagittal sinus arachnoid granulations in either young or aged animals. The data suggests that spinal and olfactory routes are the primary routes of CSF drainage and that sagittal sinus arachnoid granulations play a minor role, even in aged rats with higher ICP.

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Section: Discussionmentioning

confidence: 99%

Cerebrospinal fluid is drained primarily via the spinal canal and olfactory route in young and aged spontaneously hypertensive rats

Murtha

Yang

Parsons

et al. 2014

Fluids Barriers CNS

104

View full text Add to dashboard Cite

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“…An excellent example of these effects is the body temperature studies by Snodgrass and Lorenzo (1972); as body temperature declined in anesthetized cats, so did CSF production.This is expected since CSF formation is directly linked to choroid epithelial metabolic rate, which decreases proportionally with temperature reduction.Another example is a recent MRI study in conscious humans demonstrating that inspiration causes marked to-and-fro motion of CSF through the aqueduct of Sylvius -more than that due to cardiac pulsations.Thus, inspiration promotes mixing in the ventricular compartment (Table 2; Dreha-Kulaczewski et al, 2015). During anesthesia, with slower and shallower breathing, this mixing effect would be minimized.…”

Section: Technical Issues Pertaining To Csfmentioning

confidence: 99%

A balanced view of the cerebrospinal fluid composition and functions: Focus on adult humans

Spector

Snodgrass

Johanson

2015

Experimental Neurology

343

240

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In this review, a companion piece to our recent examination of choroid plexus (CP), the organ that secretes the cerebrospinal fluid (CSF), we focus on recent information in the context of reliable older data concerning the composition and functions of adult human CSF. To accomplish this, we define CSF, examine the methodology employed in studying the CSF focusing on ideal or near ideal experiments and discuss the pros and cons of several widely used analogical descriptions of the CSF including: the CSF as the "third circulation," the CSF as a "nourishing liquor," the similarities of the CSF/choroid plexus to the glomerular filtrate/kidney and finally the CSF circulation as part of the "glymphatic system." We also consider the close interrelationship between the CSF and extracellular space of brain through gap junctions and the paucity of data suggesting that the cerebral capillaries secrete a CSF-like fluid. Recently human CSF has been shown to be in dynamic flux with heart-beat, posture and especially respiration. Functionally, the CSF provides buoyancy, nourishment (e.g., vitamins) and endogenous waste product removal for the brain by bulk flow into the venous (arachnoid villi and nerve roots) and lymphatic (nasal) systems, and by carrier-mediated reabsorptive transport systems in CP. The CSF also presents many exogenous compounds to CP for metabolism or removal, indirectly cleansing the extracellular space of brain (e.g., of xenobiotics like penicillin). The CSF also carries hormones (e.g., leptin) from blood via CP or synthesized in CP (e.g., IGF-2) to the brain. In summary the CP/CSF, the third circulation, performs many functions comparable to the kidney including nourishing the brain and contributing to a stable internal milieu for the brain. These tasks are essential to normal adult brain functioning.

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“…The rate of formation of CSF was found to decline steadily at about 4% each hour during the last five hours of a seven hour ventriculocisternal perfusion although physiological parameters thought to influence the rate, such as intracranial pressure (Hochwald and Sahar, 1971), blood pressure (Carey and Vela, 1974), temperature (Snodgrass and Lorenzo, 1972), and PCO2 (Ames et al, 1965;Oppelt et al, 1963) were kept stable. An adequate explanation for this unexpected finding has eluded us.…”

Section: Discussionmentioning

confidence: 96%

Sources of error in measuring cerebrospinal fluid formation by ventriculocisternal perfusion.

Martins¹,

Newby²,

Doyle³

1977

Journal of Neurology, Neurosurgery & Psychiatry

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S U M M A R Y Ventriculocisternal perfusion is regarded as a precise method of measuring the rate of formation of cerebrospinal fluid (CSF) but it possesses inherent potential sources of error. Using the technique to measure CSF formation rate in the rhesus monkey, we have observed rate changes when none were expected. Most puzzling has been the steady decline of CSF formation rate at 4%/0 each hour during the final five hours of a seven hour perfusion although variables known to affect CSF formation remained stable. In addition, alterations in rate caused by artefacts were observed in experiments in which craniospinal blood volume was changed by sudden changes of either PCO2 or central venous pressure. Mobilisation or sequestration of incompletely equilibrated CSF is believed responsible. In other experiments, a small increase of intracranial pressure produced by increasing outflow resistance was quickly followed by an apparent reduction of CSF formation. We have concluded that to assess accurately the effect a variable has on the rate of CSF formation, one must control perfusion time and craniospinal blood volume as well as intracranial pressure.

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Temperature and cerebrospinal fluid production rate

Cited by 30 publications

References 0 publications

Cerebrospinal fluid is drained primarily via the spinal canal and olfactory route in young and aged spontaneously hypertensive rats

Cerebrospinal fluid is drained primarily via the spinal canal and olfactory route in young and aged spontaneously hypertensive rats

A balanced view of the cerebrospinal fluid composition and functions: Focus on adult humans

Sources of error in measuring cerebrospinal fluid formation by ventriculocisternal perfusion.

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