Biomaterial Database

Presynaptic and postsynaptic GABAB receptors of neocortical neurons of the rat in vitro: differences in pharmacology and ionic mechanisms. 1997

R A Deisz, and J M Billard, and W Zieglgänsberger

Department of Clinical Neuropharmacology, Max Planck Institute of Psychiatry, Munich, Germany. deisz@rz-charitehu-berlin.de

The properties of pre- and postsynaptic GABAB receptors were investigated with intracellular recordings from rat neocortical neurons in vitro. An antagonist of the GABAB receptor (CGP 35348) and ions or drugs interfering with GABAB receptor-mediated K+ conductance (Ba2+, QX 314) were employed to delineate possible differences. CGP 35348 reduced the conductance of the late inhibitory postsynaptic potential (IPSPB) in a dose-dependent manner. Neither the early GABAA receptor-mediated inhibitory postsynaptic potential (IPSPA), nor resting membrane potential or direct excitability, were consistently affected by CGP 35348. Bath application of 100 mumol/l Ba2+ decreased IPSPB conductance to about 40% and increased IPSPA conductance to 130% of control. The depression of a second IPSP by a pair of stimuli (paired pulse depression, or PPD) was used as an index for presynaptic GABAB receptor activation. Neither CGP 35348 nor Ba2+ exerted significant effects on the PPD at intervals of 400 msec. The dependence of PPD on the latency of the interval of the stimulus pair was investigated after intracellular applicatio of QX 314 had virtually abolished the IPSPB. Decreasing the stimulus interval from 500 msec to 100 msec revealed a stronger depression of the second IPSPA. Application of CGP 35348 alleviated PPD for stimulus intervals below 300 msec. The data indicate a distinct pharmacological difference between pre- and postsynaptic GABAB receptors. Moreover, we suggest that two temporally distinct presynaptic GABAB receptor effects contribute to PPD: a short-lasting effect, sensitive to CGP 35348, and a long-lasting effect, insensitive to CGP 35348. The latter is insensitive to Ba2+, implying that this component is not associated with a K+ conductance mechanism.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D009943	Organophosphorus Compounds	Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.	Organophosphorus Compound,Organopyrophosphorus Compound,Organopyrophosphorus Compounds,Compound, Organophosphorus,Compound, Organopyrophosphorus,Compounds, Organophosphorus,Compounds, Organopyrophosphorus
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
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
D017207	Rats, Sprague-Dawley	A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.	Holtzman Rat,Rats, Holtzman,Sprague-Dawley Rat,Rats, Sprague Dawley,Holtzman Rats,Rat, Holtzman,Rat, Sprague-Dawley,Sprague Dawley Rat,Sprague Dawley Rats,Sprague-Dawley Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus
D018080	Receptors, GABA-B	A subset of GABA RECEPTORS that signal through their interaction with HETEROTRIMERIC G-PROTEINS.	Baclofen Receptors,GABA-B Receptors,Baclofen Receptor,GABA receptor rho1,GABA type B receptor, subunit 1,GABA(B)R1,GABA(B)R1 receptor,GABA(B)R1a protein,GABA(B)R1a receptor,GABA(B)R1b protein,GABA(B)R1b receptor,GABA-B Receptor,GABBR1 protein,GB1a protein,GB1b protein,GBR1B protein,Receptors, Baclofen,rho1 subunit, GABA receptor
D018756	GABA Antagonists	Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.	gamma-Aminobutyric Acid Antagonists,GABA Antagonist,GABA Receptor Antagonists,Acid Antagonists, gamma-Aminobutyric,Antagonist, GABA,Antagonists, GABA,Antagonists, GABA Receptor,Antagonists, gamma-Aminobutyric Acid,Receptor Antagonists, GABA,gamma Aminobutyric Acid Antagonists
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In