Functional Neuroanatomy

Brookes, Simon J.; Costa, Marcello

doi:10.1002/9780470760307.ch1

Cited by 2 publications

(3 citation statements)

References 22 publications

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“…Conceivably afferent input from the gut is transmitted to the spinal cord triggering efferent discharge from somatic motor pathways. Gastric afferents enter thoracic segments, where motor efferents to the upper abdominal wall originate; conversely, colonic afferents reach more distal (lumbar) segments which innervate the lower abdominal wall 21,22 . Phrenic nerves innervating the diaphragm originate at the cervical level.…”

Section: Discussionmentioning

confidence: 99%

“…Gastric afferents enter thoracic segments, where motor efferents to the upper abdominal wall originate; conversely, colonic afferents reach more distal (lumbar) segments which innervate the lower abdominal wall. 21,22 Phrenic nerves innervating the diaphragm originate at the cervical level. The topography of visceral afferent pathways in relation to myotomes may explain site-specific viscerosomatic response.…”

Section: Discussionmentioning

confidence: 99%

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Abdominal accommodation induced by meal ingestion: differential responses to gastric and colonic volume loads

Burri

Cisternas

Villòria

et al. 2013

Neurogastroenterology Motil

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Abdominal accommodation induced by meal ingestion: differential responses to gastric and colonic volume loads

Burri

Cisternas

Villòria

et al. 2013

Neurogastroenterology Motil

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“…In Bayliss and Starling ( 1899 ) postulated the existence of an anatomical basis of these polarized enteric reflex pathways where they concluded that “the system is composed of long paths which conduct inhibitory impulses downwards, and short paths which carry augmentor impulses from one cell-station to another in an upward direction.” Nearly 100 years later such histological evidence has been provided. Indeed both the final enteric excitatory and inhibitory motor neurons to the circular muscle have unique local/oral and aboral polarities respectively and specific classes of ascending and descending interneurons are involved in these reflex pathways (Brookes and Costa, 2002b ).…”

Section: Introductionmentioning

confidence: 99%

Neural mechanisms of peristalsis in the isolated rabbit distal colon: a neuromechanical loop hypothesis

et al. 2014

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Propulsive contractions of circular muscle are largely responsible for the movements of content along the digestive tract. Mechanical and electrophysiological recordings of isolated colonic circular muscle have demonstrated that localized distension activates ascending and descending interneuronal pathways, evoking contraction orally and relaxation anally. These polarized enteric reflex pathways can theoretically be sequentially activated by the mechanical stimulation of the advancing contents. Here, we test the hypothesis that initiation and propagation of peristaltic contractions involves a neuromechanical loop; that is an initial gut distension activates local and oral reflex contraction and anal reflex relaxation, the subsequent movement of content then acts as new mechanical stimulus triggering sequentially reflex contractions/relaxations at each point of the gut resulting in a propulsive peristaltic contraction. In fluid filled isolated rabbit distal colon, we combined spatiotemporal mapping of gut diameter and intraluminal pressure with a new analytical method, allowing us to identify when and where active (neurally-driven) contraction or relaxation occurs. Our data indicate that gut dilation is associated with propagating peristaltic contractions, and that the associated level of dilation is greater than that preceding non-propagating contractions (2.7 ± 1.4 mm vs. 1.6 ± 1.2 mm; P < 0.0001). These propagating contractions lead to the formation of boluses that are propelled by oral active neurally driven contractions. The propelled boluses also activate neurally driven anal relaxations, in a diameter dependent manner. These data support the hypothesis that neural peristalsis is the consequence of the activation of a functional loop involving mechanical dilation which activates polarized enteric circuits. These produce propulsion of the bolus which activates further anally, polarized enteric circuits by distension, thus closing the neuromechanical loop.

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Functional Neuroanatomy

Cited by 2 publications

References 22 publications

Abdominal accommodation induced by meal ingestion: differential responses to gastric and colonic volume loads

Abdominal accommodation induced by meal ingestion: differential responses to gastric and colonic volume loads

Neural mechanisms of peristalsis in the isolated rabbit distal colon: a neuromechanical loop hypothesis

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