scholarly journals Properties of spontaneous electrical activity in the mouse proximal colon.

2019 ◽  
Vol 92 (0) ◽  
pp. 1-O-10
Author(s):  
Yoshihiko Kito ◽  
Masaaki Kurahashi
Keyword(s):  
Electrical Activity ◽  
Proximal Colon ◽  
Spontaneous Electrical Activity

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

Electrical activity of the ventromedial nucleus of the hypothalamus

1959 ◽  
Vol 197 (4) ◽  
pp. 829-834 ◽  
Author(s):  
Dana C. Brooks
Keyword(s):  
Electrical Activity ◽  
Slow Waves ◽  
Ventromedial Nucleus ◽  
Spontaneous Electrical Activity ◽  
Pentobarbital Anesthesia

The spontaneous electrical activity of the ventromedial nucleus was studied in the cat under pentobarbital anesthesia and in the unanesthetized, unrestrained state. Under light pentobarbital anesthesia the activity of the nucleus is characterized by a predominant 9–15 cps, 50–100 µv component which is uniform from second to second. With small additional doses of anesthesia there is a selective depression of this activity; with recovery from light anesthesia this activity is gradually replaced by irregular, large, slow waves characteristic of sleep. When the unanesthetized animal is aroused 20–35 cps activity having an amplitude of 40 µv or more appears in the nucleus. While the pattern of activity during sleep resembles that seen elsewhere in the hypothalamus, the activity seen during barbiturate anesthesia and during arousal is confined to the nucleus and not seen in other parts of the diencephalon.

Optical approaches to ontogeny of electrical activity and related functional organization during early heart development

1991 ◽  
Vol 71 (1) ◽  
pp. 53-91 ◽  
Author(s):  
K. Kamino
Keyword(s):  
Electrical Activity ◽  
Heart Development ◽  
Functional Organization ◽  
Embryonic Heart ◽  
Optical Recording ◽  
Additional Advantage ◽  
Physiological Functions ◽  
Spontaneous Electrical Activity ◽  
Somite Stage ◽  
Voltage Sensitive Dyes

Direct intracellular measurement of electrical events in the early embryonic heart is impossible because the cells are too small and frail to be impaled with microelectrodes; it is also not possible to apply conventional electrophysiological techniques to the early embryonic heart. For these reasons, complete understanding of the ontogeny of electrical activity and related physiological functions of the heart during early development has been hampered. Optical signals from voltage-sensitive dyes have provided a new powerful tool for monitoring changes in transmembrane voltage in a wide variety of living preparations. With this technique it is possible to make optical recordings from the cells that are inaccessible to microelectrodes. An additional advantage of the optical method for recording membrane potential activity is that electrical activity can be monitored simultaneously from many sites in a preparation. Thus, applying a multiple-site optical recording method with a 100- or 144-element photodiode array and voltage-sensitive dyes, we have been able to monitor, for the first time, spontaneous electrical activity in prefused cardiac primordia in the early chick embryos at the six- and the early seven-somite stages of development. We were able to determine that the time of initiation of the contraction is the middle period of the nine-somite stage. In the rat embryonic heart, the onset of spontaneous electrical activity and contraction occurs at the three-somite stage. In this review, a new view of the ontogenetic sequence of spontaneous electrical activity and related physiological functions such as ionic properties, pacemaker function, conduction, and characteristics of excitation-contraction coupling in the early embryonic heart are discussed.

Long-term observations of spontaneous electrical activity of the uterine smooth muscle

1959 ◽  
Vol 196 (2) ◽  
pp. 343-350 ◽  
Author(s):  
C. Y. Kao
Keyword(s):  
Smooth Muscle ◽  
Electrical Activity ◽  
Action Potentials ◽  
Local Conditions ◽  
Pregnant Uterus ◽  
Implanted Electrodes ◽  
Spontaneous Electrical Activity ◽  
Myometrial Cells ◽  
Uterine Smooth Muscle

The spontaneous electrical activity of uterine smooth muscle was rather variable when acute observations were made. Therefore, a series of chronic experiments was performed with implanted electrodes to monitor a group of myometrial cells under different physiological conditions for periods up to eight weeks. The results showed that consistent behavior of myometrial cells could be observed provided similar hormonal status was maintained. Action potentials were rare or absent in myometrium of oophorectomized animals but were caused to appear by estrogen. In the pregnant uterus, action potentials increased both in amplitude and frequency of discharge as parturition approached, reached a peak at that time, and then declined in the postpartum days. The results indicated that in estrogen treatment and in parturition activities of myometrial cells were more synchronous. There was suggestive evidence that there were central impulses initiating activity in the pregnant uterus, and that the responses of the myometrium were affected by the local conditions.

Nucleotide action on spontaneous electrical activity of calcium deficient nerve

1967 ◽  
Vol 70 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Albert S. Kuperman ◽  
Michiko Okamoto ◽  
Elaine Gallin
Keyword(s):  
Electrical Activity ◽  
Spontaneous Electrical Activity

GASTROINTESTINAL HYPOMOTILITY IN MAGNESIUM-DEFICIENT SHEEP

1980 ◽  
Vol 60 (2) ◽  
pp. 293-301 ◽  
Author(s):  
L. BUENO ◽  
J. FIORAMONTI ◽  
E. GEUX ◽  
Y. RAISSIGUIER
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Electrical Activity ◽  
Digestive Tract ◽  
Experimental Period ◽  
Proximal Colon ◽  
Slow Waves ◽  
Deficient Diet ◽  
Intravenous Infusions ◽  
Spiking Activity

The electrical activity of the gastrointestinal tract and gallbladder was recorded in four sheep fed a Mg-deficient diet during 10 to 15 days. The mitigating effect of intravenous infusions of MgCl2 was tested at the end of the experimental period in animals presenting hypomagnesemia. Motility of the reticulo-rumen remained unchanged in Mg-deficient sheep except that there was no postprandial increased frequency of contractions. By contrast, the contractions of gallbladder, cecum and proximal colon were reduced in both amplitude and frequency. The amplitude but not the frequency of the antro-duodenal slow-waves was reduced. The amplitude of the regular spiking activity of the small intestine was reduced as well as the number of complexes produced per day. The activity of the spiral colon was correlated to the blood magnesium concentrations but Mg infusion was unable to restore immediately the motor profile of the rest of the gut to its intitial level. This was done within 2–3 days by changes in the diet in three of the four animals. It is concluded that the motility of the whole digestive tract, including the reticulo-rumen, is modified on a Mg-deficient diet and that hypomagnesemia, involved in the atony of the spiral colon, is only one of the factors responsible for the hypomotility.

Sign in / Sign up

Export Citation Format

Share Document