Effects of serotonin on synaptic and intrinsic properties of rat subicular neurons in vitro.
Intracellular recordings were performed to study the effects of 5-HT on membrane properties and EPSP/IPSP responses of subicular neurons in rat combined hippocampal-entorhinal cortex slices. Application of 5-HT induced in 76% of the investigated subicular cells a hyperpolarization and a reduction of membrane resistance. In bursting neurons, 5-HT caused a reduction of the depolarizing envelope underlying burst discharges and attenuated the subsequent afterhyperpolarization. While 5-HT decreased isolated AMPA/kainate and NMDA receptor-mediated responses as well as slow IPSPs, we could not find a consistent effect on isolated fast IPSPs. Since in approximately 25% of subicular neurons EPSPs and slow IPSPs were reduced without any increase of membrane conductance, we conclude that 5-HT has in addition to membrane effects also effects on synaptic currents.
Behr
J
J
Department of Neurology, Reed Neurological Research Center, UCLA School of Medicine, Los Angeles, CA 90095-1769, USA.
Empson
R M
RM
Schmitz
D
D
Gloveli
T
T
Heinemann
U
U
D000818:Animals; D018728:Entorhinal Cortex / Q000187:drug effects / Q000502:physiology*; D005071:Evoked Potentials / Q000187:drug effects* / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010721:Phosphinic Acids / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D010721:Phosphinic Acids; D011412:Propanolamines; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C085075:CGP 55845A; D012701:Serotonin