Ca2+ mobilizing agents mimic serotonin 5-HT2A facilitation of N-methyl-D-aspartate depolarization.
Serotonin activation of 5-HT2A receptors facilitates depolarization of neocortical neurons by N-methyl-D-aspartate (NMDA). Using grease-gap recordings from an in vitro cortical wedge preparation we have examined whether agents which raise the concentration of intracellular Ca2+ mimic the facilitation. Perfusing A23187, cyclopiazonic acid or thapsigargin selectively facilitate the NMDA depolarization of cortical neurons in a concentration-dependent manner. Buffering intracellular Ca2+ by perfusing BAPTA-AM eliminates the serotonin, cyclopiazonic acid and thapsigargin induced facilitation. We conclude that a rise in intracellular Ca2+ is both necessary and sufficient to account for facilitating the NMDA depolarization following activation of 5-HT2A receptors.
Neuman
R S
RS
Faculty of Medicine, Memorial University of Newfoundland, Canada.
Rahman
S
S
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D016764:Cell Polarity / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000134:cerebrospinal fluid / Q000494:pharmacology*; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D016202:N-Methylaspartate / Q000134:cerebrospinal fluid / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology
D002614:Chelating Agents; D004791:Enzyme Inhibitors; D018690:Excitatory Amino Acid Agonists; D007211:Indoles; D007476:Ionophores; D011985:Receptors, Serotonin; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D000001:Calcimycin; D004533:Egtazic Acid; D016202:N-Methylaspartate; D019284:Thapsigargin; D000252:Calcium-Transporting ATPases; D002118:Calcium; C000543:cyclopiazonic acid