Oculodentodigital dysplasia (ODDD) is a rare autosomal dominant inherited disease caused by mutations of the human gap junction alpha 1 gene, which encodes the protein Connexin-43. Patients with ODDD may present with neurological deficits with a typical pleiotropic combination of characteristic craniofacial, ophthalmological, phalangeal, and dental anomalies. In this report, we describe the first genetically confirmed Korean ODDD patient, who presented with spastic paraparesis. We will also review the neurological aspects of ODDD as reported in the literature.
Gap Junctions ; Humans ; Muscle Spasticity* ; Paraparesis, Spastic*

The aim of this study was to evaluate the histopathologic changes of the pigmented rabbit ratina after endocryopexy. We investigated the differences or similarity among endocryopexy, transscleral cryopexy and laser phocoagulation. Their ultrastructural changes were observed with light and electron microscope. The results were as follows; 1. The first day after endocryopexy, we observed rupture of the internal limiting membrane, breakdown the inner and outer retina, separation of intercellular gap junction of pigment epithelial cells, and accumulation of exudation within subretinal space. 2. In the 8th days, there are mull iplication of retinal pigment epithelial cell layer and development of basal infolding. 3. The present study suggested that effects of endocryopexy on the retina to cause chorioretinal adhesion was similar to transscleral cryopexy or laser photocoagulation However it should be operated on the premise that in requires technical skill for the purpose of clinical application.
Epithelial Cells ; Gap Junctions ; Light Coagulation ; Membranes ; Retina* ; Retinaldehyde ; Rupture

Horizontal cells (HCs) of the mammalian retina are interneurons that provide negative feedback to photoreceptors in the outer plexiform layer (OPL) where the first synapse occurs and contribute to the center surround antagonism that underlies the receptive field properties of many retinal neurons. These functions of HCs are thought to be attributed to their coupled network via gap junctions. Two kinds of connexin (Cx) proteins, Cx50 and 57 are known to form gap junctions of HCs. However, little is known about precise localization of gap junctions within HCs. Thus, this study was designed to determine the localization of HC gap junctions at subcellular level. In vertical ultrathin sections of the rabbit retina, gap junctions composed of Cx50 and 57 were identified in the OPL by the electron-dense reaction products. Each Cx50 and 57 gap junction on putative HC processes showed its own distinct features. Cx50 gap junction was bigger in size and localized more proximally than Cx57. In addition, Cx57 gap junctions had distinct shape. That is, about a half of them appeared to be invaginated or endocytosed in shape. The differences in shape, size and subcellular localization between Cx50 and 57 gap junctions may provide the insights into the function of different types of horizontal cell.
Gap Junctions ; Interneurons ; Proteins ; Retina ; Retinal Neurons ; Synapses

Connexins (Cx) are membrane proteins and monomers for forming gap junction (GJ) channels. Cx46 and Cx50 are also known to function as conductive hemichannels. As part of an ongoing effort to find GJ-specific blocker(s), endocrine disruptors were used to examine their effect on Cx46 hemichannels expressed in Xenopus oocytes. Voltage-dependent gating of Cx46 hemichannels was characterized by slowly activating outward currents and relatively fast inward tail currents. Bisphenol A (BPA, 10 nM) reduced outward currents of Cx46 hemichannels up to ~18% of control, and its effect was reversible (n=5). 4-tert-Octylphenol (OP, 1 microM) reversibly reduced outward hemichannel currents up to ~28% (n=4). However, overall shapes of Cx46 hemichannel current traces (outward and inward currents) were not changed by these drugs. These results suggest that BPA and OP are likely to occupy the pore of Cx46 hemichannels and thus obstruct the ionic fluxes. This finding provides that BPA and OP are potential candidates for GJ channel blockers.
Connexins ; Endocrine Disruptors ; Gap Junctions ; Membrane Proteins ; Oocytes ; Xenopus

The contractility of corporal smooth muscle plays a critical role in human penile erectile process. Understanding the initiation, maintenance and modulation of corporal smooth muscle tone is a prequisite to improve understanding, diagnosis and treatment of erectile dysfunction. Despite this fact, indentification of both the precise mechanistic basis by which various agents exert their effects on individual corporal smooth muscle cells, moreover, the process by which these signals are spread among the diverse array of parenchymal cells in the paired corporal, remain somewhat of a physiological enigma. Therefore, this article aims at: 1. to review current knowledge of the regulation of corporal smooth muscle tone at the cellular and molecular level; 2. to review various methods used in the study of gap junction channel.
Animals ; Connexins ; physiology ; Gap Junctions ; physiology ; Humans ; Intercellular Junctions ; physiology ; Male ; Muscle, Smooth ; physiology ; Penis ; cytology

OBJECTIVEThis review discusses the experimental and clinical studies those show the expression of connexin 36 in the central nervous system and the possible role of connexin 36 in epileptic seizure.

DATA SOURCESAll articles used in this review were mainly searched from PubMed published in English from 1996 to 2012.

STUDY SELECTIONOriginal articles and reviews were selected if they were related to the expression of connexin 36 in the central nervous system and its role in epilepsy.

RESULTSThe distribution of connexin 36 is developmentally regulated, cell-specific and region-specific. Connexin 36 is involved in some neuronal functions and epileptic synchronization. Changes in the connexin 36 gene and protein were accompanied by seizures. Selective gap junction blockers have exerted anticonvulsant actions in a variety of experiments examined in both humans and experimental animals.

CONCLUSIONSConnexin 36 plays an important role in both physiological and pathological conditions in the central nervous system. A better understanding of the role of connexin 36 in seizure activity may contribute to the development of new therapeutic approaches to treating epilepsy.

Animals ; Central Nervous System ; metabolism ; Connexins ; metabolism ; Gap Junctions ; metabolism ; Humans ; Seizures ; metabolism

OBJECTIVETo investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes.

METHODSPrimary cultured cerebral cortical astrocytes of neonate rats were divided into normal control group, hypoxia reoxygenation injury group and 18-α-glycyrrhetinic acid and oleamide (gap junctional intercellular channel inhibitors) group. The gap junction intercellular communication was determined by Parachute assay. The viability of astrocyes was detected by MTT assay. The apoptosis of astrocytes were detected with annexin V/PI and Hoechst 33258 staining.

RESULTSCompared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (P<0.01), the surviving fraction of astrocytes decreased significantly (P<0.01) and its cell apoptosis ratio increased significantly (P<0.01). Compared with the ischemia/reperfusion group, the gap junctional function of astrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (P<0.01), the viability of astrocytes increased significantly (P<0.01), while cell apoptosis decreased significantly (P<0.01).

CONCLUSIONInhibition of intercellular gap junction has protective effect against hypoxia/reoxygenation injury in astrocytes.

Animals ; Apoptosis ; Astrocytes ; cytology ; pathology ; Cell Communication ; Cell Hypoxia ; Cells, Cultured ; Gap Junctions ; Oxygen ; Rats

Gap junction is the aggregate of some intercellular channels, which allows ions and small molecules to transport or transfer between cells. There are about 20 proposed members of the connexin family found in mammalian tissues now, and more than 10 reported are expressed in the nervous system. The astrocytes and oligodendrocytes express some specific connexins. In the present article, we review the recent literatures to illustrate the importance of gap junction for the intercellular communication between glial cells, astrocytes and neurons, and neuronal cells, which is crucial for brain functions.
Brain ; metabolism ; physiology ; Connexins ; metabolism ; Gap Junctions ; metabolism ; physiology ; Humans ; Neuroglia ; metabolism ; physiology ; Neurons ; metabolism ; physiology

OBJECTIVETo investigate the possible relationship between the analgesic effect of acupuncture and connexin 43.

METHODSConnexin 43 gene knock-out mice were divided into 4 groups: a wide type (WT) control group, a WT acupuncture group, a heterozygous (HT) control group and HT acupuncture group. Hot-plate test and writhing response induced by acetic acid were used for investigating the analgesic effect of acupuncture.

RESULTSThere was no significant difference in the basic pain threshold value between HT and WT mice (P > 0.05). Acupuncture could significantly increase the pain threshold value, prolong the latency period of writhing body and decrease the number of writhing body as compared with pre-acupuncture in WT and HT mice (P < 0.01 or P < 0.05). The pain threshold, latency period of writhing and number of writhing body in HT mice were less than WT mice post-acupuncture (P < 0.05).

CONCLUSIONConnexin 43 gene knock-out might partially inhibit the analgesic effect of acupuncture, suggesting that connexin 43 is possibly related with meridians and the effect of acupuncture.

Acupuncture Analgesia ; Animals ; Connexin 43 ; genetics ; physiology ; Female ; Gap Junctions ; physiology ; Male ; Mice ; Pain Threshold

Little is known about how gap junctions are involved in the respiratory-related or other types of physiological neuronal activity since physiologically active gap junction currents (GJCs) have never been characterized from single respiratory-related neurons or from single neurons of any other types. In the present study we hypothesized that GJCs could be selectively revealed from single neurons by elimination of transmembrane electrochemical gradients in voltage patch-clamp recording, and this hypothesis was tested in single inspiratory tracheal preganglionic vagal motor neurons (I-TPVMs). The results showed that GJCs were selectively revealed in all I-TPVMs when the transmembrane electrochemical gradients were eliminated in voltage patch-clamp recording, and were rhythmically activated by central inspiratory activity. Therefore, this method may be used as a fast way to detect GJCs within spontaneously active neuronal networks.
Gap Junctions ; physiology ; Motor Neurons ; physiology ; Patch-Clamp Techniques ; Trachea ; cytology