The GABA(A) receptor complex in the developing chick optic tectum: characterization of benzodiazepine and
A Cubero1, S Fernández-Quero, A Batuecas
1Centro de Biologia Molecular (CSIC-UAM), Canto Blanco, 28049 Madrid, Spain.
Abstract:
By use of membrane preparations and incubation conditions optimized for each binding site, we have characterized the benzodiazepine and ionophore-linked-convulsant/barbiturate modulatory sites within the chick tectal GABA(A) receptor complex. Using [(3)H]flunitrazepam (FNZ) and [(35)S]t-butylbicyclophosphorothionate (TBPS), respectively, as specific radioligand probes for the two sites, we have found in each case one single population of high-affinity, saturable, specific binding sites. The apparent dissociation constants (K(d)) show no change during tectal development (9 nM for [(3)H]FNZ, and 25-28 nM for [(35)S]TBPS) while the respective densities of binding sites at saturation (B(max)) experience in both cases a twofold increase between embryonic day 16 and postnatal day 10. Ligand-specific pharmacological profiles and allosteric interactions between the transmitter and modulatory sites appear to be well preserved in the chick tectal membrane preparations employed in this study.
More Related Videos
Related Concept Videos
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Transducer Mechanism: G Protein–Coupled Receptors
GPCRs are also called heptahelical, 7TM, or...
G Protein-coupled Receptors
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
G-Protein Gated Ion Channels
Sensory organs,...
G-protein Coupled Receptors


