 |
 Previous Article | Next Article 
Journal of Neuroscience, Vol 12, 1502-1510, Copyright © 1992 by Society for Neuroscience
Convergence of reflex pathways excited by distension and mechanical stimulation of the mucosa onto the same myenteric neurons of the guinea pig small intestine
TK Smith, JC Bornstein and JB Furness
Centre for Neuroscience, Flinders University School of Medicine, Bedford Park, South Australia.
The effects on morphologically and electrophysiologically characterized
myenteric neurons of activation of intestinal reflex pathways were examined
in vitro. Opened segments of guinea pig small intestine were pinned serosa
down in an organ bath that had two balloons set into its base. A
5-10-mm-wide strip of myenteric plexus between the balloons was exposed
from the mucosal side, and neurons were impaled with microelectrodes.
Reflex pathways were stimulated by inflation of the balloons to distend the
intestinal wall, and by deforming the exposed mucosal villi with a brush.
Impaled neurons were classified electrophysiologically as AH-neurons or
S-neurons (Hirst et al., 1974) and were injected with biocytin to determine
their shapes and projections. None of the 58 AH-neurons responded to
distension. In contrast, 63 of 131 S-neurons responded to distension with a
burst of fast EPSPs; about one-third of the responding S-neurons received
input from ascending reflex pathways, one-third received input from
descending reflex pathways, and one-third received input from both
ascending and descending pathways. Most neurons in this last group supplied
extensive varicose branches to the tertiary plexus and were probably
longitudinal muscle motor neurons. Neurons receiving input from only one
pathway usually projected in the direction of that pathway; many of these
were circular muscle motor neurons. Almost all neurons responding to
distension were also excited by deforming the villi. Responses evoked by
distension or deforming the mucosa declined when stimuli were repeated at
intervals less than 10 sec. This was seen in ascending and descending
pathways but was more prominent in the former. Deforming the mucosa evoked
a normal response even when the response to repeated distensions had
disappeared. It is concluded that distension and deforming the mucosa
excite separate populations of sensory neurons to activate reflex pathways
that converge onto common motor neurons and probably onto common
interneurons.
This article has been cited by other articles:
|
|
|
|
 
G.-D. Wang, X.-Y. Wang, H.-Z. Hu, S. Liu, N. Gao, X. Fang, Y. Xia, and J. D. Wood
Inhibitory neuromuscular transmission mediated by the P2Y1 purinergic receptor in guinea pig small intestine
Am J Physiol Gastrointest Liver Physiol,
June 1, 2007;
292(6):
G1483 - G1489.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Spencer, E. J. Dickson, G. W. Hennig, and T. K. Smith
Sensory elements within the circular muscle are essential for mechanotransduction of ongoing peristaltic reflex activity in guinea-pig distal colon
J. Physiol.,
October 15, 2006;
576(2):
519 - 531.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Mao, B. Wang, and W. Kunze
Characterization of Myenteric Sensory Neurons in the Mouse Small Intestine
J Neurophysiol,
September 1, 2006;
96(3):
998 - 1010.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Patton, M. O'Reilly, and S. Vanner
Sensory peptide neurotransmitters mediating mucosal and distension evoked neural vasodilator reflexes in guinea pig ileum
Am J Physiol Gastrointest Liver Physiol,
November 1, 2005;
289(5):
G785 - G790.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Spencer and T. K. Smith
Mechanosensory S-neurons rather than AH-neurons appear to generate a rhythmic motor pattern in guinea-pig distal colon
J. Physiol.,
July 15, 2004;
558(2):
577 - 596.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Bisschops, P. Vanden Berghe, E. Bellon, J. Janssens, and J. Tack
Electrical stimulation reveals complex neuronal input and activation patterns in single myenteric guinea pig ganglia
Am J Physiol Gastrointest Liver Physiol,
June 1, 2003;
284(6):
G1084 - G1092.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. H. Kang, P. Vanden Berghe, and T. K. Smith
Ca2+-activated Cl- current in cultured myenteric neurons from murine proximal colon
Am J Physiol Cell Physiol,
April 1, 2003;
284(4):
C839 - C847.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Spencer, G. W. Hennig, and T. K. Smith
Stretch-activated neuronal pathways to longitudinal and circular muscle in guinea pig distal colon
Am J Physiol Gastrointest Liver Physiol,
February 1, 2003;
284(2):
G231 - G241.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Vanden Berghe, J. L. Kenyon, and T. K. Smith
Mitochondrial Ca2+ Uptake Regulates the Excitability of Myenteric Neurons
J. Neurosci.,
August 15, 2002;
22(16):
6962 - 6971.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. H. Percy, J. T. Brunz, R. E. Burgers, T. H. Fromm, C. L. Merkwan, and J. van Dis
Interrelationship between colonic muscularis mucosae activity and changes in transmucosal potential difference
Am J Physiol Gastrointest Liver Physiol,
August 1, 2001;
281(2):
G479 - G489.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Hillsley, J. L. Kenyon, and T. K. Smith
Ryanodine-Sensitive Stores Regulate the Excitability of AH Neurons in the Myenteric Plexus of Guinea-Pig Ileum
J Neurophysiol,
December 1, 2000;
84(6):
2777 - 2785.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Vogalis, K. Hillsley, and T. K. Smith
Diverse Ionic Currents and Electrical Activity of Cultured Myenteric Neurons From the Guinea Pig Proximal Colon
J Neurophysiol,
March 1, 2000;
83(3):
1253 - 1263.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. J. LePard and J. J. Galligan
Analysis of fast synaptic pathways in myenteric plexus of guinea pig ileum
Am J Physiol Gastrointest Liver Physiol,
February 1, 1999;
276(2):
G529 - G538.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. D. J. Thornton and J. C. Bornstein
Slow excitatory synaptic potentials evoked by distension in myenteric descending interneurones of guinea-pig ileum
J. Physiol.,
March 1, 2002;
539(2):
589 - 602.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
