Biomaterial Database

(-)-baclofen and gamma-aminobutyric acid inhibit calcium currents in isolated retinal ganglion cells. 1991

V P Bindokas, and A T Ishida

Department of Animal Physiology, University of California, Davis 95616.

Of the various synaptic inputs known to converge upon retinal ganglion cells, the major inhibitory inputs are thought to be GABAergic. Although gamma-aminobutyric acid (GABA) is known to activate anion-selective ion channels in retinal ganglion cells, we have tested the possibility that GABA can also modulate cationic conductances in these cells, as seen in other central and peripheral neurons. Specifically, we have made whole-cell patch-clamp recordings to test whether voltage-gated calcium currents in isolated goldfish retinal ganglion cells are sensitive to GABAB receptor ligands. (-)-Baclofen and GABA inhibited calcium currents activated by moderately long depolarizations and, during large depolarizations (e.g., to 0 mV), also appeared to accelerate the rate of current decay. The calcium current inhibition induced by (-)-baclofen and GABA was not prevented by 2-hydroxysaclofen, phaclofen, or bicuculline, even though bicuculline suppressed a GABA-activated conductance in these cells. These results demonstrate the presence of baclofen- and GABA-sensitive calcium currents in vertebrate retinal ganglion cells as well as the coexistence of GABAA and GABAB receptors in individual retinal ganglion cells.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011963	Receptors, GABA-A	Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and contain an integral membrane chloride channel. Each receptor is assembled as a pentamer from a pool of at least 19 different possible subunits. The receptors belong to a superfamily that share a common CYSTEINE loop.	Benzodiazepine-Gaba Receptors,GABA-A Receptors,Receptors, Benzodiazepine,Receptors, Benzodiazepine-GABA,Receptors, Diazepam,Receptors, GABA-Benzodiazepine,Receptors, Muscimol,Benzodiazepine Receptor,Benzodiazepine Receptors,Benzodiazepine-GABA Receptor,Diazepam Receptor,Diazepam Receptors,GABA(A) Receptor,GABA-A Receptor,GABA-A Receptor alpha Subunit,GABA-A Receptor beta Subunit,GABA-A Receptor delta Subunit,GABA-A Receptor epsilon Subunit,GABA-A Receptor gamma Subunit,GABA-A Receptor rho Subunit,GABA-Benzodiazepine Receptor,GABA-Benzodiazepine Receptors,Muscimol Receptor,Muscimol Receptors,delta Subunit, GABA-A Receptor,epsilon Subunit, GABA-A Receptor,gamma-Aminobutyric Acid Subtype A Receptors,Benzodiazepine GABA Receptor,Benzodiazepine Gaba Receptors,GABA A Receptor,GABA A Receptor alpha Subunit,GABA A Receptor beta Subunit,GABA A Receptor delta Subunit,GABA A Receptor epsilon Subunit,GABA A Receptor gamma Subunit,GABA A Receptor rho Subunit,GABA A Receptors,GABA Benzodiazepine Receptor,GABA Benzodiazepine Receptors,Receptor, Benzodiazepine,Receptor, Benzodiazepine-GABA,Receptor, Diazepam,Receptor, GABA-A,Receptor, GABA-Benzodiazepine,Receptor, Muscimol,Receptors, Benzodiazepine GABA,Receptors, GABA A,Receptors, GABA Benzodiazepine,delta Subunit, GABA A Receptor,epsilon Subunit, GABA A Receptor,gamma Aminobutyric Acid Subtype A Receptors
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D003035	Cobalt	A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.	Cobalt-59,Cobalt 59
D005680	gamma-Aminobutyric Acid	The most common inhibitory neurotransmitter in the central nervous system.	4-Aminobutyric Acid,GABA,4-Aminobutanoic Acid,Aminalon,Aminalone,Gammalon,Lithium GABA,gamma-Aminobutyric Acid, Calcium Salt (2:1),gamma-Aminobutyric Acid, Hydrochloride,gamma-Aminobutyric Acid, Monolithium Salt,gamma-Aminobutyric Acid, Monosodium Salt,gamma-Aminobutyric Acid, Zinc Salt (2:1),4 Aminobutanoic Acid,4 Aminobutyric Acid,Acid, Hydrochloride gamma-Aminobutyric,GABA, Lithium,Hydrochloride gamma-Aminobutyric Acid,gamma Aminobutyric Acid,gamma Aminobutyric Acid, Hydrochloride,gamma Aminobutyric Acid, Monolithium Salt,gamma Aminobutyric Acid, Monosodium Salt
D006054	Goldfish	Common name for Carassius auratus, a type of carp (CARPS).	Carassius auratus
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
D001418	Baclofen	A GAMMA-AMINOBUTYRIC ACID derivative that is a specific agonist of GABA-B RECEPTORS. It is used in the treatment of MUSCLE SPASTICITY, especially that due to SPINAL CORD INJURIES. Its therapeutic effects result from actions at spinal and supraspinal sites, generally the reduction of excitatory transmission.	Baclophen,Chlorophenyl GABA,Apo-Baclofen,Atrofen,Ba-34,647,Ba-34647,Baclofen AWD,Baclofène-Irex,Baclospas,CIBA-34,647-BA,Clofen,Gen-Baclofen,Genpharm,Lebic,Lioresal,Liorésal,Nu-Baclo,PCP-GABA,PMS-Baclofen,beta-(Aminomethyl)-4-chlorobenzenepropanoic Acid,beta-(p-Chlorophenyl)-gamma-aminobutyric Acid,AWD, Baclofen,Apo Baclofen,ApoBaclofen,Ba34,647,Ba34647,Baclofène Irex,BaclofèneIrex,CIBA34,647BA,GABA, Chlorophenyl,Gen Baclofen,GenBaclofen,Nu Baclo,NuBaclo,PMS Baclofen,PMSBaclofen
D001640	Bicuculline	An isoquinoline alkaloid obtained from Dicentra cucullaria and other plants. It is a competitive antagonist for GABA-A receptors.	6-(5,6,7,8-Tetrahydro-6-methyl-1,3-dioxolo(4,5-g)isoquinolin-5-yl)furo(3,4-e)1,3-benzodioxol-8(6H)one
D012165	Retinal Ganglion Cells	Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.	Cell, Retinal Ganglion,Cells, Retinal Ganglion,Ganglion Cell, Retinal,Ganglion Cells, Retinal,Retinal Ganglion Cell