The microcirculation of the area postrema in the rat

Roth, Gerald I.; Yamamoto, William S.

doi:10.1002/cne.901330304

Cited by 73 publications

(27 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Capillaries lack proteins associated with tight junctions such as occluding 1 and claudin (Maolood and Meister, 2009). Perivascular spaces that contain large nerve cells and processes are also observed (Roth and Yamamoto 1968;Spacek and Parizek, 1969;Dempsey, 1973;Armstrong et al, 1982).…”

Section: Area Postremamentioning

confidence: 95%

Circumventricular Organs

Oldfield

2015

The Rat Nervous System

View full text Add to dashboard Cite

Section: Area Postremamentioning

confidence: 95%

Circumventricular Organs

Oldfield

2015

The Rat Nervous System

View full text Add to dashboard Cite

“…In this regard, it is important to remember that large areas of the DVC, as well as the whole adjacent area postrema, are located outside the blood–brain barrier, have a large network of fenestrated capillaries and contact specialized neurons lining the ependymal layer of the central canal and fourth ventricle 29,78,79,130 . This anatomi cal arrangement, combined with the non-selective toxicity of capsaicin, suggests strongly that the mechanism(s) of action of CCK, as well as that of many other gastrointestinal peptides, is not exclusively para crine and involves other areas, including neurons of the DVC, where CCK receptors and CCK-containing neurons are also located 22,131,132 .…”

Section: Gastrointestinal Peptidesmentioning

confidence: 99%

Vagal neurocircuitry and its influence on gastric motility

Travagli

Anselmi

2016

Nat Rev Gastroenterol Hepatol

211

240

View full text Add to dashboard Cite

A large body of research has been dedicated to the effects of gastrointestinal peptides on vagal afferent fibres, yet multiple lines of evidence indicate that gastrointestinal peptides also modulate brainstem vagal neurocircuitry, and that this modulation has a fundamental role in the physiology and pathophysiology of the upper gastrointestinal tract. In fact, brainstem vagovagal neurocircuits comprise highly plastic neurons and synapses connecting afferent vagal fibres, second order neurons of the nucleus tractus solitarius (NTS), and efferent fibres originating in the dorsal motor nucleus of the vagus (DMV). Neuronal communication between the NTS and DMV is regulated by the presence of a variety of inputs, both from within the brainstem itself as well as from higher centres, which utilize an array of neurotransmitters and neuromodulators. Because of the circumventricular nature of these brainstem areas, circulating hormones can also modulate the vagal output to the upper gastrointestinal tract. This Review summarizes the organization and function of vagovagal reflex control of the upper gastrointestinal tract, presents data on the plasticity within these neurocircuits after stress, and discusses the gastrointestinal dysfunctions observed in Parkinson disease as examples of physiological adjustment and maladaptation of these reflexes.

show abstract

“…The AP is located dorsal to the NTS, outside the blood-brain and cerebrospinal fluid barriers, and possesses active influx and efflux transport proteins [3] and sensitivity to bloodborne chemicals [17]. Furthermore, capillaries from the AP make vascular links with the NTS, which itself has fenestrated capillaries with high permeability [23,47]. Exogenously administered SP can be degraded rapidly in larger species [19,41] and particularly quickly in the least shrew, given that a large emetic dose (50 mg/kg, i.p.)…”

Section: Behavioral Effects Of Substance P Relate To Cns Penetrationmentioning

confidence: 99%

Utilization of the least shrew as a rapid and selective screening model for the antiemetic potential and brain penetration of substance P and NK1 receptor antagonists

et al. 2008

View full text Add to dashboard Cite

Substance P (SP) is thought to play a cardinal role in emesis via the activation of central tachykinin NK 1 receptors during the delayed phase of vomiting produced by chemotherapeutics. Although the existing supportive evidence is significant, due to lack of an appropriate animal model, the evidence is indirect. As yet, no study has confirmed that emesis produced by SP or a selective NK 1 receptor agonist is sensitive to brain penetrating antagonists of either NK 1 , NK 2 , or NK 3 receptors. The goals of this investigation were to demonstrate: 1) whether intraperitoneal (i.p.) administration of either SP, a brain penetrating (GR73632) or non-penetrating (e.g. SarMet -SP) NK 1 receptor agonist, an NK 2 receptor agonist (GR64349), or an NK 3 receptor agonist (Pro 7 -NKB), would induce vomiting and/or scratching in the least shrew (Cryptotis parva) in a dose-dependent manner; and whether these effects are sensitive to the above selective receptor antagonists; 2) whether an exogenous emetic dose of SP (50 mg/kg, i.p.) can penetrate into the shrew brain stem and frontal cortex; 3) whether GR73632 (2.5 mg/kg, i.p.)-induced activation of NK 1 receptors increases Fos-measured neuronal activity in the neurons of both brain stem emetic nuclei and the enteric nervous system of the gut; and 4) whether selective ablation of peripheral NK 1 receptors can affect emesis produced by GR73632. The results clearly demonstrated that while SP produced vomiting only, GR73632 caused both emesis and scratching behavior dose-dependently in shrews, and these effects were sensitive to NK 1 -, but not NK 2 -or NK 3 -receptor antagonists. Neither the selective, non-penetrating NK 1 receptor agonists, nor the selective NK 2 -or NK 3 -receptor agonists, caused a significant dose-dependent behavioral effect. An emetic dose of SP selectively and rapidly penetrated the brain stem but not the frontal cortex. Systemic GR73632 increased Fos expression in the enteric nerve plexi, the medial subnucleus of nucleus tractus solitarius, and the dorsal motor nucleus of the vagus, but not the area postrema. Ablation of peripheral NK 1 receptors attenuated the ability of GR73632 to induce a maximal frequency of emesis and shifted its percent animals vomiting dose-response curve to the right. The NK 1 -ablated shrews exhibited scratching behavior after systemic GR73632-injection. These results, for the first time, affirm a cardinal role for central NK 1 receptors in SP-induced vomiting, and a Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. facilitatory role for gastrointestinal NK 1 receptors. In addition, the...

show abstract

The microcirculation of the area postrema in the rat

Cited by 73 publications

References 24 publications

Circumventricular Organs

Circumventricular Organs

Vagal neurocircuitry and its influence on gastric motility

Utilization of the least shrew as a rapid and selective screening model for the antiemetic potential and brain penetration of substance P and NK1 receptor antagonists

Contact Info

Product

Resources

About