Biomaterial Database

Chloride channels gated by extrajunctional glutamate receptors (H-receptors) on locust leg muscle. 1989

J Dudel, and C Franke, and H Hatt, and P N Usherwood

Physiologisches Institut der Technischen Universität München, F.R.G.

Outside-out patches of extrasynaptic membrane were isolated from leg muscles of locusts. L-Glutamate and its agonists were applied to such patches either continuously or in rapidly switched pulses. When the pipette contained a high chloride concentration, 2.5 x 10(-5) M glutamate triggered single-channel currents (gated by H-receptors) with a conductance of 25 pS which were carried by chloride, in addition to cationic channels (gated by D-receptors). For the chloride channels, the distribution of channel open times had components of about 2 and 12 ms. Pulses of higher glutamate concentrations elicited many superimposed channel openings, and the approximately saturating concentration of 10(-3) M glutamate opened 100-200 channels simultaneously. When the pipette contained low chloride, channel conductance was reduced, and the current voltage relation was shifted towards the now negative chloride equilibrium potential. H-Receptor-gated chloride channels were activated by glutamate, ibotenate and aspartate, but not by GABA, quisqualate, kainate, N-methyl-D-aspartate and carbachol. The currents declined in the continued presence of agonist showing a time constant of desensitization greater than 1 s. Recovery from desensitization after removal of the agonist was tested with double pulses and was found to have a time constant of about 300 ms.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D006110	Grasshoppers	Plant-eating orthopterans having hindlegs adapted for jumping. There are two main families: Acrididae and Romaleidae. Some of the more common genera are: Melanoplus, the most common grasshopper; Conocephalus, the eastern meadow grasshopper; and Pterophylla, the true katydid.	Acrididae,Locusts,Romaleidae,Grasshopper,Locust
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D017470	Receptors, Glutamate	Cell-surface proteins that bind glutamate and trigger changes which influence the behavior of cells. Glutamate receptors include ionotropic receptors (AMPA, kainate, and N-methyl-D-aspartate receptors), which directly control ion channels, and metabotropic receptors which act through second messenger systems. Glutamate receptors are the most common mediators of fast excitatory synaptic transmission in the central nervous system. They have also been implicated in the mechanisms of memory and of many diseases.	Excitatory Amino Acid Receptors,Glutamate Receptors,Receptors, Excitatory Amino Acid,Excitatory Amino Acid Receptor,Glutamate Receptor,Receptor, Glutamate
D017981	Receptors, Neurotransmitter	Cell surface receptors that bind signalling molecules released by neurons and convert these signals into intracellular changes influencing the behavior of cells. Neurotransmitter is used here in its most general sense, including not only messengers that act to regulate ion channels, but also those which act on second messenger systems and those which may act at a distance from their release sites. Included are receptors for neuromodulators, neuroregulators, neuromediators, and neurohumors, whether or not located at synapses.	Neurohumor Receptors,Neuromediator Receptors,Neuromodulator Receptors,Neuroregulator Receptors,Receptors, Neurohumor,Receptors, Synaptic,Synaptic Receptor,Synaptic Receptors,Neuromediator Receptor,Neuromodulator Receptor,Neuroregulator Receptor,Neurotransmitter Receptor,Receptors, Neuromediators,Receptors, Neuromodulators,Receptors, Neuroregulators,Receptors, Neurotransmitters,Neuromediators Receptors,Neuromodulators Receptors,Neuroregulators Receptors,Neurotransmitter Receptors,Neurotransmitters Receptors,Receptor, Neuromediator,Receptor, Neuromodulator,Receptor, Neuroregulator,Receptor, Neurotransmitter,Receptor, Synaptic,Receptors, Neuromediator,Receptors, Neuromodulator,Receptors, Neuroregulator
D018698	Glutamic Acid	A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.	Aluminum L-Glutamate,Glutamate,Potassium Glutamate,D-Glutamate,Glutamic Acid, (D)-Isomer,L-Glutamate,L-Glutamic Acid,Aluminum L Glutamate,D Glutamate,Glutamate, Potassium,L Glutamate,L Glutamic Acid,L-Glutamate, Aluminum