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Review
. 2008 Aug 7;149(1-3):11-4.
doi: 10.1016/j.regpep.2007.08.027. Epub 2008 Apr 7.

The blood-brain barrier: connecting the gut and the brain

William A Banks  1
Affiliations
Review

The blood-brain barrier: connecting the gut and the brain

William A Banks. Regul Pept. .

Abstract

The BBB prevents the unrestricted exchange of substances between the central nervous system (CNS) and the blood. The blood-brain barrier (BBB) also conveys information between the CNS and the gastrointestinal (GI) tract through several mechanisms. Here, we review three of those mechanisms. First, the BBB selectively transports some peptides and regulatory proteins in the blood-to-brain or the brain-to-blood direction. The ability of GI hormones to affect functions of the BBB, as illustrated by the ability of insulin to alter the BBB transport of amino acids and drugs, represents a second mechanism. A third mechanism is the ability of GI hormones to affect the secretion by the BBB of substances that themselves affect feeding and appetite, such as nitric oxide and cytokines. By these and other mechanisms, the BBB regulates communications between the CNS and GI tract.

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Figures

Figure 1
Figure 1
A schematic of the vascular blood-brain barrier. The physical barrier and transporters reside at the brain endothelial cell. However induction, maintenance, and modulation of barrier and transporter function is influenced by other cells types with and outside the central nervous system. Chief among these regulatory cells are the astrocytes and pericytes. The astrocytes project endfeet that form a mesh- or net-like structure surrounding the brain capillaries. Pericytes lie within the basement membrane next to the brain endothelial cells. Microglia within the brain and circulating immune cells, hormones and cytokines also likely influence BBB function.
Figure 2
Figure 2
The three mechanism discussed here by which the blood-brain barrier (BBB) participates in gut-brain communication. Number 1 is by direct transfer of peptides and regulatory proteins across the BBB; number 2 is the ability of gastrointestinal (GI) hormones to alter the functioning of the brain endothelial cells which comprise the BBB; number 3 is the ability of GI hormones to alter the secretion from the BBB of substances which have effects on feeding.
See this image and copyright information in PMC

References

    1. Smith GP, Gibbs J, Jerome C, Pi-Sunyer FX, Kissileff HR, Thornton J. The satiety effect of cholecystokinin: a progress report. Peptides. 1981;2 2:57–59. - PubMed
    1. Kelley KW, Bluthe RM, Dantzer R, Zhou JH, Shen WH, Johnson RW, Broussard SR. Cytokine-induced sickness behavior. Brain, Behavior, and Immunity. 2003;17:S112–S118. - PubMed
    1. Romeo HE, Tio DL, Rahman SU, Chiappelli F, Taylor AN. The glossopharyngeal nerve as a novel pathway in immune-to-brain communication: relevance to neuroimmune surveillance of the oral cavity. J Neuroimmunol. 2001;115:91–100. - PubMed
    1. Watkins LR, Maier SF, Goehler LE. Cytokine-to-brain communication: a review & analysis of alternative mechanisms. Life Sci. 1995;57:1011–1026. - PubMed
    1. Davson H, Segal MB. Physiology of the CSF and Blood-Brain Barriers. Boca Raton: CRC Press; 1996.

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