Development pattern of the GABAA-benzodiazepine receptor ionophore complex in primary cultures of cortical neurons.
The development pattern of the GABAA/benzodiazepine (BZ) receptor ionophore complex was characterized in mammalian cortical cultured neurons utilizing radioligand binding and GABA-induced 36Cl-influx. The specific binding of [3H]flunitrazepam, [3H]Ro15-1788 and [3H]Ro15-4513 increased with time from day 3 to day 21. The EC50 value and Emax of the GABA, muscimol and pentobarbital to enhance [3H]-flunitrazepam binding did not change during the development. Furthermore, GABA-induced 36Cl- influx also did not change during development from day 3 to day 21. However, the potency of ligands that bind to type-1 BZ receptors (alprazolam, zolpidem and C1218,872) to inhibit [3H]flunitrazepam binding increased from day 7 to day 21. Taken together, these data suggest the presence of type-II BZ receptors in early stages of the development which appears to change to type-I BZ receptors with age in the cortical neurons in culture.
Department of Pharmacology, University of Texas, San Antonio.
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Ticku
D000345:Affinity Labels; D000818:Animals; D001386:Azides / Q000493:pharmacokinetics; D001569:Benzodiazepines / Q000493:pharmacokinetics; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D005442:Flumazenil / Q000493:pharmacokinetics; D005445:Flunitrazepam / Q000493:pharmacokinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009118:Muscimol / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*
D000345:Affinity Labels; D001386:Azides; D002712:Chlorides; D011963:Receptors, GABA-A; D001569:Benzodiazepines; D009118:Muscimol; D005442:Flumazenil; D005445:Flunitrazepam; C042957:Ro 15-4513