Serine proteases excite myenteric neurons through protease-activated receptors in guinea pig small intestine

2002 ◽  
Vol 123 (5) ◽  
pp. 1554-1564 ◽  
Author(s):  
Chuanyun Gao ◽  
Sumei Liu ◽  
Hong–Zhen Hu ◽  
Na Gao ◽  
Gordon Y. Kim ◽  
...  
2001 ◽  
Vol 120 (5) ◽  
pp. A683-A683
Author(s):  
J GUZMAN ◽  
S SHARP ◽  
J YU ◽  
F MCMORRIS ◽  
A WIEMELT ◽  
...  

2001 ◽  
Vol 120 (5) ◽  
pp. A114-A114
Author(s):  
C GAO ◽  
H HU ◽  
S LIU ◽  
N GAO ◽  
Y XIA ◽  
...  

1992 ◽  
Vol 262 (6) ◽  
pp. G1074-G1078 ◽  
Author(s):  
L. V. Baidan ◽  
A. V. Zholos ◽  
M. F. Shuba ◽  
J. D. Wood

The results of our research established the feasibility of applying patch-clamp methods in the study of the cellular neurophysiology of myenteric neurons enzymatically dissociated from adult guinea pig small intestine. Recording in current-clamp mode revealed two populations of neurons. One population discharged repetitively during depolarizing current pulses and displayed anodal-break excitation reminiscent of S/type 1 myenteric neurons. In the second population, spike discharge was limited to one or two spikes at the onset of depolarizing pulses and was similar to the behavior of AH/type 2 neurons. Recording in voltage-clamp mode revealed a complex of overlapping inward and outward whole cell currents. Fast and slow components of inward current were interpreted as sodium and calcium currents, respectively. Outward currents were blocked by cesium and consisted of components with properties of delayed rectifier current and A-type potassium current.


1986 ◽  
Vol 55 (6) ◽  
pp. 1395-1406 ◽  
Author(s):  
K. Furukawa ◽  
G. S. Taylor ◽  
R. A. Bywater

Intracellular recordings have been made in vitro from the myenteric neurons of the distal colon of normal littermates of the piebald-lethal mouse. Out of a total of 90 neurons, 82 were classified as S/type 1 cells and 8 as AH/type 2 cells. Seventy-eight out of 82 S cells showed spontaneous fast excitatory postsynaptic potentials (EPSPs) sensitive to d-tubocurarine (dTC, 280 microM), and 22 S cells showed spontaneous action potentials (APs). Six S cells and 1 AH cell showed spontaneous nonnicotinic slow depolarizations associated with an increase in the input resistance of the cells; during the spontaneous slow depolarization in the S cells there was an increase in the frequency of nicotinic fast EPSPs and APs. Three S cells showed spontaneously occurring regular oscillations of the membrane potential (approximately mV in amplitude and approximately 4/min). Transmural nerve stimulation produced fast EPSPs with a wide range of latencies (3 ms to 20 s) in S cells; the fast EPSPs were blocked by dTC (280 microM) or solutions containing low Ca2+ (0.25 mM) and high Mg2+ (12 mM) but not by atropine (ATR, 14 microM). Single or repetitive transmural stimulation produced slow EPSPs in 24 S cells and 3 AH cells; these were not blocked by dTC (280 microM) nor ATR (14 microM). During the slow EPSPs there was an increase in the input resistance of the cells. In those S cells that showed slow EPSPs there were many long-latency fast EPSPs; long-latency fast EPSPs were also observed in 11 other S cells that did not show a slow EPSP following repetitive transmural nerve stimulation. Long-latency fast EPSPs may be related to the firing of other neurons during their slow EPSPs. The myenteric neurons in the mouse colon have similar properties to the myenteric neurons in the guinea pig small intestine. However, the colonic myenteric neurons show more ongoing synaptic activity and more prolonged activity after nerve stimulation than myenteric neurons in the guinea pig small intestine. This activity may be due to regional differences, species differences, or preparation differences (in this study the myenteric plexus was adherent to the underlying circular muscle layer).


2001 ◽  
Vol 120 (5) ◽  
pp. A114 ◽  
Author(s):  
Chuanyun Gao ◽  
Hong-Zhen Hu ◽  
Sumei Liu ◽  
Na Gao ◽  
Yun Xia ◽  
...  

2005 ◽  
Vol 118 (1-2) ◽  
pp. 88-92 ◽  
Author(s):  
Yoshifumi Katayama ◽  
Kiyotoshi Ooishi ◽  
Keiji Hirai ◽  
Tomoo Homma ◽  
Yumi Noda

1993 ◽  
Vol 265 (5) ◽  
pp. G887-G893 ◽  
Author(s):  
K. Tamura ◽  
M. Schemann ◽  
J. D. Wood

Sodium nitroprusside (NaNP) was used as a donor of nitric oxide (NO) to investigate actions of NO on electrical and synaptic behavior of single myenteric neurons in guinea pig small intestine. NaNP (10 microM-1 mM) did not affect resting membrane properties of the neurons, except for an occasional decrease in input resistance and hyperpolarization attributable to suppression of excitatory transmitter release. NaNP did not alter fast nicotinic neurotransmission but suppressed noncholinergic slow excitatory postsynaptic potentials (slow EPSPs) in a concentration-dependent manner. Pretreatment with either methylene blue or oxyhemoglobin reduced the inhibitory action of NaNP on the slow EPSPs. Slow EPSP-like responses to microejected substance P or 5-hydroxytryptamine were unaffected by NaNP. The nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester, did not affect resting membrane excitability or excitatory synaptic events in any of the myenteric neurons. The results suggest that NO may not be released extensively as a neurotransmitter at synapses within the myenteric plexus. If myenteric neurons are exposed to NO released from nonneural sources, then the principal action is expected to be presynaptic inhibition of slow synaptic excitation.


Sign in / Sign up

Export Citation Format

Share Document