Original scientific paper
https://doi.org/10.3325/cmj.2014.55.328
Virchow-Robin space and aquaporin-4: new insights on an old friend
Tsutomu Nakada
; Center for Integrated Human Brain Science, Brain Research Institute University of Niigata, Niigata, Japan
Abstract
Recent studies have strongly indicated that the classic circulation
model of cerebrospinal fluid (CSF) is no longer
valid. The production of CSF is not only dependent on
the choroid plexus but also on water flux in the peri-capillary
(Virchow Robin) space. Historically, CSF flow through
the Virchow Robin space is known as interstitial flow, the
physiological significance of which is now fully understood.
This article briefly reviews the modern concept of
CSF physiology and the Virchow-Robin space, in particular
its functionalities critical for central nervous system neural
activities. Water influx into the Virchow Robin space
and, hence, interstitial flow is regulated by aquaporin-4
(AQP-4) localized in the endfeet of astrocytes, connecting
the intracellular cytosolic fluid space of astrocytes and the
Virchow Robin space. Interstitial flow has a functionality
equivalent to systemic lymphatics, on which clearance of
β-amyloid is strongly dependent. Autoregulation of brain
blood flow serves to maintain a constant inner capillary
fluid pressure, allowing fluid pressure of the Virchow Robin
space to regulate regional cerebral blood flow (rCBF)
based on AQP-4 gating. Excess heat produced by neural
activities is effectively removed from the area of activation
by increased rCBF by closing AQP-4 channels. This neural
flow coupling (NFC) is likely mediated by heat generated
proton channels.
Keywords
Hrčak ID:
129939
URI
Publication date:
15.8.2014.
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