Joseph H. Szurszewski

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Interstitial cells of Cajal (ICC) generate the electrical slow wave required for normal gastrointestinal motility. The ionic conductances expressed in human intestinal ICC are unknown. The aim of this study was to determine expression of a Na+ current in human intestinal ICC and to determine the effects of the Na+ current on the slow wave. Visually(More)
Nitric oxide (NO) and carbon monoxide (CO) seem to be neurotransmitters in the brain. The colocalization of their respective biosynthetic enzymes, neuronal NO synthase (nNOS) and heme oxygenase-2 (HO2), in enteric neurons and altered intestinal function in mice with genomic deletion of the enzymes (nNOS(Delta/Delta) and HO2(Delta/Delta)) suggest(More)
Tetrodotoxin-resistant Na+currents are expressed in a variety of muscle cells including human jejunal circular smooth muscle (HJCSM) cells. The aim of this study was to determine the molecular identity of the pore-forming alpha-subunit of the HJCSM Na+ channel. Degenerate primers identified a cDNA fragment of 1.5 kb with 99% nucleotide homology with human(More)
Postganglionic parasympathetic neurons of the opossum gallbladder were studied using morphological and intracellular electrophysiological recording techniques. On average there were 17 ganglia/cm2 with 8 neurons/ganglion arranged as loosely or densely packed clusters. Intracellular injection of horseradish peroxidase identified two types of neurons. Most of(More)
The gaseous molecule hydrogen sulfide (H(2)S) has been proposed as an endogenous signal molecule and neuromodulator in mammals. Using a newly developed method, we report here for the first time the ability of intact and living brain and colonic tissue in the mouse to generate and release H(2)S. This production occurs through the activity of two enzymes,(More)
1. In vitro studies were conducted on neurons within the inferior mesenteric ganglion (IMG) of guinea pigs to investigate how intrinsic features of the spike-generating process interact with preganglionic inputs to produce the output firing patterns of these neurons. Intracellular-electrode techniques were used to monitor and control electrical activity of(More)
Intestinofugal afferent neurones (IFANs) are a unique subset of myenteric ganglion neurones that regulate normal gastrointestinal function. The IFANs relaying mechanosensory information to sympathetic neurones of the prevertebral ganglion (PVG) function as volume detectors. It is possible that mechanosensory information arriving in the PVG via axon(More)
We investigated the effect of pituitary adenylate cyclase activating peptide (PACAP) on the colon-inferior mesenteric ganglion (IMG) reflex loop in vitro. PACAP27 and PACAP38 applied to the IMG caused a prolonged depolarization and intense generation of fast EPSPs and action potentials in IMG neurones. Activation of PACAP-preferring receptors (PAC1-Rs) with(More)
1. A perforated patch clamp technique was used to study an outward potassium current in freshly dissociated circular smooth muscle cells of the canine jejunum. 2. A voltage-dependent outward current was identified which was highly potassium selective, weakly holding voltage sensitive, increased its open probability at -65 mV, and reached unit open(More)
The aims of this study were to quantify the change in resting membrane potential (RMP) across the thickness of the circular muscle layer in the mouse and human small intestine and to determine whether the gradient in RMP is dependent on the endogenous production of carbon monoxide (CO). Conventional sharp glass microelectrodes were used to record the RMPs(More)