Interstitial cells of Cajal and electrical activity in ganglionic and aganglionic colons of mice

2002 ◽  
Vol 283 (2) ◽  
pp. G445-G456 ◽  
Author(s):  
Sean M. Ward ◽  
Michael D. Gershon ◽  
Kathleen Keef ◽  
Yulia R. Bayguinov ◽  
Cheryl Nelson ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Proximal Colon ◽  
Neural Responses ◽  
Wild Type ◽  
Circular Layer ◽  
Excitatory Junction Potentials ◽  
Cells Of Cajal

An antibody directed against Kit protein was used to investigate the distribution of interstitial cells of Cajal (ICC) within the murine colon. The ICC density was greatest in the proximal colon and decreased along its length. The distribution of the different classes of ICC in the aganglionic colons of lethal spotted ( ls/ls) mice was found to be similar in age-matched wild-type controls. There were marked differences in the electrical activities of the colons from ls/ls mutants compared with wild-type controls. In ls/ls aganglionic colons, the circular muscle was electrically quiescent compared with the spontaneous spiking electrical activity of wild-type tissues. In ls/ls aganglionic colons, postjunctional neural responses were greatly affected. Inhibitory junction potentials were absent or excitatory junction potentials inhibited by atropine were observed. In conclusion, the distribution of ICC in the ganglionic and aganglionic regions of the colons from ls/ls mutants appeared similar to that of wild-type controls. The electrical activity and neural responses of the circular layer are significantly different in aganglionic segments of ls/ls mutants.

scholarly journals Comparison of mechanical and electrical activity and interstitial cells of Cajal in urinary bladders from wild-type andW/Wvmice

2009 ◽  
Vol 156 (2) ◽  
pp. 273-283 ◽  
Author(s):  
KD McCloskey ◽  
UA Anderson ◽  
RA Davidson ◽  
YR Bayguinov ◽  
KM Sanders ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Wild Type ◽  
Cells Of Cajal

scholarly journals Interstitial cells of Cajal generate spontaneous transient depolarizations in the rat gastric fundus

2009 ◽  
Vol 297 (4) ◽  
pp. G814-G824 ◽  
Author(s):  
Yoshihiko Kito ◽  
Kenton M. Sanders ◽  
Sean M. Ward ◽  
Hikaru Suzuki
Keyword(s):  
Electrical Activity ◽  
Interstitial Cells Of Cajal ◽  
Maximum Amplitude ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Gastric Fundus ◽  
Double Labeling ◽  
Membrane Hyperpolarization ◽  
Cells Of Cajal ◽  
Rat Gastric Fundus

Intracellular recordings were made from isolated circular muscle bundles of rat gastric fundus. The majority of cells generated an ongoing discharge of electrical activity that were ≤10 mV in amplitude (unitary potentials). A second pattern of electrical activity was recorded in less than 1% of all impalements. This electrical activity was characterized by high frequency, large amplitude spontaneous transient depolarizations (STDs) with a maximum rate of rise (d V/d tmax) of 0.5 V/s. Injection of the fluorescent dye propidium iodide into cells and double labeling with an antibody against the Kit receptor revealed that unitary potentials were recorded from circular smooth muscle cells (CSMC), whereas STDs were generated by intramuscular interstitial cells of Cajal (ICC-IM). Sustained injection periods (>15 min) resulted in the spread of dye between CSMC, between ICC-IM, and between CSMC and ICC-IM. Two types of STDs were observed, regularly occurring continuous STDs and irregular noisy bursting STDs. The amplitude of STDs varied between the two types of STDs. Single units summed to develop STDs with a maximum amplitude of 30 mV. Sodium nitroprusside (3 μM) induced membrane hyperpolarization and abolished unitary potentials generated by CSMC. In contrast, the amplitude of STDs generated by ICC-IM was increased with membrane hyperpolarization. Hyperpolarization induced by pinacidil (10 μM) also increased the amplitude of STDs and enhanced d V/d tmax. These observations indicate that STDs generated in ICC-IM spread passively to the adjacent CSMC to evoke the discharge of unitary potentials in the gastric fundus.

Morphology of the canine pyloric sphincter in relation to function

1989 ◽  
Vol 67 (12) ◽  
pp. 1560-1573 ◽  
Author(s):  
E. E. Daniel ◽  
I. Berezin ◽  
H. D. Allescher ◽  
H. Manaka ◽  
V. Posey-Daniel
Keyword(s):  
Smooth Muscle ◽  
Substance P ◽  
Smooth Muscle Cells ◽  
Gap Junctions ◽  
Vasoactive Intestinal Polypeptide ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Pyloric Sphincter ◽  
Cells Of Cajal

The ultrastructure and immunocytochemistry of the canine distal pyloric muscle loop, the pyloric sphincter, were studied. Cells in this muscle were connected by gap junctions, fewer than in the antrum or corpus. The sphincter had a dense innervation and a sparse population of interstitial cells of Cajal. Most such cells were of the circular muscle type but a few were of the type in the myenteric plexus. Nerves were sometimes associated with interstitial cell profiles, but most nerves were neither close to nor associated with interstitial cells nor close to smooth muscle cells. Nerve profiles were characterized by an unusually high proportion of varicosities with a majority or a high proportion of large granular vesicles. Many of these were shown to contain material immunoreactive for vasoactive intestinal polypeptide (VIP) and some had substance P (SP) immunoreactive material. All were presumed to be peptidergic. VIP was present in a higher concentration in this muscle than in adjacent antral or duodenal circular muscle. Interstitial cells of Cajal made gap junctions to smooth muscle and to one another and might provide myogenic pacemaking activity for this muscle, but there was no evidence of a close or special relationship between nerves with VIP or SP and these cells. The absence of close relationships between nerves and either interstitial cells or smooth muscle cells leaves unanswered questions about the structural basis for previous observations of discrete excitatory responses or pyloric sphincter to single stimuli or nerves up to one per second. In conclusion, the structural observations suggest that this muscle has special neural and myogenic control systems and that interstitial cells may function to control myogenic activity of this muscle but not to mediate neural signals.Key words: vasoactive intestinal polypeptide, interstitial cells of Cajal, neuropeptides, gap junctions, substance P.

Neuromuscular structures in opossum esophagus: role of interstitial cells of Cajal

1984 ◽  
Vol 246 (3) ◽  
pp. G305-G315 ◽  
Author(s):  
E. E. Daniel ◽  
V. Posey-Daniel
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Muscle Cells ◽  
Interstitial Cells ◽  
Complete Relaxation ◽  
Granular Vesicles ◽  
Cells Of Cajal

The structures of the lower esophageal sphincter (LES) and body circular muscle (BCM) from opossum were compared as to neural and muscular structures and the structural relations of interstitial cells of Cajal to nerves and muscle cells. Both LES and BCM were densely innervated by nerves with varicosities containing many small agranular vesicles and a few large granular vesicles. These nerves were more closely related structurally to the interstitial cells of Cajal than to smooth muscle cells. More gap junctions were observed between smooth muscle cells and between interstitial cells of Cajal and smooth muscle cells in BCM than in LES. Those between smooth muscle cells were larger in BCM. Complete relaxation of the LES strip by isoproterenol reduced these differences but did not eliminate them. The finding that interstitial cells of Cajal often had gap-junction contacts to smooth muscle and close associations with nerves is consistent with the hypothesis that interstitial cells are intercalated between the nerves and muscles and may mediate nerve responses. These findings also suggest that LES muscle cells may be less well coupled electrically than BCM muscle cells.

Patterns of electrical activity and neural responses in canine proximal duodenum

1992 ◽  
Vol 263 (6) ◽  
pp. G887-G894 ◽  
Author(s):  
O. Bayguinov ◽  
F. Vogalis ◽  
B. Morris ◽  
K. M. Sanders
Keyword(s):  
Electrical Activity ◽  
Circular Muscle ◽  
Sphincter Of Oddi ◽  
Electrical Field Stimulation ◽  
Muscle Cells ◽  
Proximal Region ◽  
Inhibitory Neurotransmitter ◽  
Proximal Duodenum ◽  
Circular Layer ◽  
Excitatory Junction Potentials

The patterns of electrical activity and neural inputs to the proximal duodenum between the pyloric sphincter and the sphincter of Oddi were studied in muscles of the dog. Smooth muscle cells in the most proximal region were electrically quiescent, but slow waves were recorded in all regions distal to the first few millimeters. Electrical activity was recorded from circular muscle cells near the myenteric and submucosal surfaces of the circular layer, and slow wave activity was similar in both regions. The nature of neural inputs was also characterized. With electrical field stimulation, responses in cells near the submucosal surface were predominantly excitatory junction potentials (EJPs); near the myenteric border responses were either inhibitory junction potentials (IJPs) or biphasic responses (i.e., small EJPs followed by IJPs). EJPs were blocked by atropine. IJPs were nonadrenergic and noncholinergic (NANC), and several experiments suggested that nitric oxide (NO), or a NO-releasing compound, serves as the inhibitory neurotransmitter in this region. Exogenous NO caused hyperpolarization of membrane potential. IJPs and the hyperpolarization response to NO were sensitive to apamin. These data describe the myogenic mechanisms and neurogenic apparatus that appear to regulate motility in the most proximal region of the duodenum.

Do gap junctions play a role in nerve transmissions as well as pacing in mouse intestine?

2007 ◽  
Vol 292 (3) ◽  
pp. G734-G745 ◽  
Author(s):  
E. E. Daniel ◽  
Ahmed El Yazbi ◽  
Marco Mannarino ◽  
Gary Galante ◽  
Geoffrey Boddy ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Electrical Field Stimulation ◽  
Cell Types ◽  
Interstitial Cells ◽  
Glycyrrhetinic Acid ◽  
Mouse Intestine ◽  
Cells Of Cajal

Varicosities of nitrergic and other nerves end on deep muscular plexus interstitial cells of Cajal or on CD34-positive, c- kit-negative fibroblast-like cells. Both cell types connect to outer circular muscle by gap junctions, which may transmit nerve messages to muscle. We tested the hypotheses that gap junctions transmit pacing messages from interstitial cells of Cajal of the myenteric plexus. Effects of inhibitors of gap junction conductance were studied on paced contractions and nerve transmissions in small segments of circular muscle of mouse intestine. Using electrical field stimulation parameters (50 V/cm, 5 pps, and 0.5 ms) which evoke near maximal responses to nitrergic, cholinergic, and apamin-sensitive nerve stimulation, we isolated inhibitory responses to nitrergic nerves, inhibitory responses to apamin-sensitive nerves and excitatory responses to cholinergic nerves. 18β-Glycyrrhetinic acid (10, 30, and 100 μM), octanol (0.1, 0.3, and 1 mM) and gap peptides (300 μM of40Gap27,43Gap26,37,43Gap27) all failed to abolish neurotransmission. 18β-Glycyrrhetinic acid inhibited frequencies of paced contractions, likely owing to inhibition of l-type Ca2+channels in smooth muscle, but octanol or gap peptides did not. 18β-Glycyrrhetinic acid and octanol, but not gap peptides, reduced the amplitudes of spontaneous and nerve-induced contractions. These reductions paralleled reductions in contractions to exogenous carbachol. Additional experiments with gap peptides in both longitudinal and circular muscle segments after NG-nitro-l-arginine and TTX revealed no effects on pacing frequencies. We conclude that gap junction coupling may not be necessary for pacing or nerve transmission to the circular muscle of the mouse intestine.

Proteins of interstitial cells of Cajal and intestinal smooth muscle, colocalized with caveolin-1

2005 ◽  
Vol 288 (3) ◽  
pp. G571-G585 ◽  
Author(s):  
Woo Jung Cho ◽  
E. E. Daniel
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Gap Junction ◽  
Interstitial Cells Of Cajal ◽  
Smooth Muscles ◽  
Circular Muscle ◽  
Interstitial Cells ◽  
Caveolin 1 ◽  
Cells Of Cajal ◽  
Junction Proteins

The murine jejunum and lower esophageal sphincter (LES) were examined to determine the locations of various signaling molecules and their colocalization with caveolin-1 and one another. Caveolin-1 was present in punctate sites of the plasma membranes (PM) of all smooth muscles and diffusely in all classes of interstitial cells of Cajal (ICC; identified by c-kit immunoreactivity), ICC-myenteric plexus (MP), ICC-deep muscular plexus (DMP), ICC-serosa (ICC-S), and ICC-intramuscularis (IM). In general, all ICC also contained the L-type Ca2+ (L-Ca2+) channel, the PM Ca2+ pump, and the Na+/Ca2+ exchanger-1 localized with caveolin-1. ICC in various sites also contained Ca2+-sequestering molecules such as calreticulin and calsequestrin. Calreticulin was present also in smooth muscle, frequently in the cytosol, whereas calsequestrin was present in skeletal muscle of the esophagus. Gap junction proteins connexin-43 and -40 were present in circular muscle of jejunum but not in longitudinal muscle or in LES. In some cases, these proteins were associated with ICC-DMP. The large-conductance Ca2+-activated K+ channel was present in smooth muscle and skeletal muscle of esophagus and some ICC but was not colocalized with caveolin-1. These findings suggest that all ICC have several Ca2+-handling and -sequestering molecules, although the functions of only the L-Ca2+ channel are currently known. They also suggest that gap junction proteins are located at sites where ultrastructural gap junctions are know to exist in circular muscle of intestine but not in other smooth muscles. These findings also point to the need to evaluate the function of Ca2+ sequestration in ICC.

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