title: Modulation of low calcium induced field bursts in the hippocampus by monoamines and cholinomimetics.
abstract: The influence of monoamine transmitter candidates, acetylcholine and related substances on rhythmic depolarization shifts (field bursts) in the CA 1 area of hippocampal slices from rats in low calcium (0.2 mmol X 1(-1) ) high magnesium (4 mmol X 1(-1) ) was investigated. Acetylcholine (ACh), histamine (HA) and H2-agonists, noradrenaline (NA) and beta-agonists at nano- to micromolar concentrations as well as dopamine (DA) and 8-bromo-cyclic AMP at 100 mumol X 1(-1) accelerated the field bursts. H2-antagonists blocked HA actions, beta-antagonists blocked NA actions selectively; muscarinic antagonists blocked ACh, HA and NA actions. H1-agonists, serotonin, dopamine and adenosine slowed the field bursts at micromolar concentrations. These effects parallel the action of the tested substances on afterhyperpolarizations in CA 1 pyramidal cells. High sensitivity and specificity make this response of the field bursts an excellent model to study postsynaptic transmitter actions in the central nervous system.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002395:Catecholamines / Q000494:pharmacology*; D000242:Cyclic AMP / Q000494:pharmacology*; D004594:Electrophysiology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D006632:Histamine / Q000494:pharmacology*; D010277:Parasympathomimetics / Q000494:pharmacology*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D002395:Catecholamines; D010277:Parasympathomimetics; D012701:Serotonin; D006632:Histamine; D000242:Cyclic AMP; D002118:Calcium