title: Reduction in bioelectric GABA and NMDA responses in organotypic neocortical explants by chronic elevation of potassium.
abstract: Long-term cultures of organotypic neonatal rat neocortex slices were maintained in a serum-free medium supplemented with 25 mM potassium. Such cultures continue to be bioelectrically silent upon return to a 5 mM potassium medium. The absence of responses to pressure ejected gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) from neurons in treated explants suggests that one consequence of chronic depolarization is a reduction in the density of postsynaptic transmitter receptors. [3H]Muscimol binding to neocortical membrane preparations shows a large reduction in the binding of this agonist to GABAA receptors. These data show that the quantitative expression of at least one neurotransmitter receptor, the GABAA receptor, relies on voltage-dependent activity in developing neocortical neurons in vitro.
authors.affiliation: Netherlands Institute for Brain Research, Amsterdam.
authors.forename: R E
authors.initials: RE
authors.lastname: Baker
authors.forename: J M
authors.initials: JM
authors.lastname: Ruijter
authors.forename: J
authors.initials: J
authors.lastname: Walden
authors.forename: D
authors.initials: D
authors.lastname: Bingmann
authors.forename: H
authors.initials: H
authors.lastname: Straub
authors.forename: E J
authors.initials: EJ
authors.lastname: Speckmann
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009118:Muscimol / Q000378:metabolism; D016202:N-Methylaspartate / Q000378:metabolism* / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009924:Organ Culture Techniques; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D011963:Receptors, GABA-A; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D011188:Potassium