Prolonged administration of imipramine and (+)-oxaprotiline, but not citalopram, results in sensitization of the rat hippocampal CA1 neurons to serotonin ex vivo.
Prolonged (14 days, twice daily), but not acute, application of imipramine and (+)-oxaprotiline (10 mg/kg) induced sensitization of hippocampal CA1 neurons to the inhibitory effect of 5-hydroxytryptamine (5-HT), as studied ex vivo in the rat hippocampal slice preparation. Attenuation of the population spike, recorded in the CA1 pyramidal cell layer in response to stimulation of the Schaffer collateral-commisural pathway, was used to asses the sensitivity of neurons to 5-HT. Prolonged and acute administration of the selective 5-HT reuptake blocker citalopram did not change the responsiveness of hippocampal neurons to 5-HT. Since imipramine and (+)-oxaprotiline share the inhibitory effect on the norepinephrine reuptake, our results may indicate that long-term alterations in the noradrenergic system lead to modifications in postsynaptic serotonergic receptors.
Bijak
M
M
Institute of Pharmacology, Polish Academy of Sciences, Kraków.
Tokarski
K
K
D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D015283:Citalopram / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D007099:Imipramine / Q000008:administration & dosage / Q000494:pharmacology; D066298:In Vitro Techniques; D008376:Maprotiline / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*; D013134:Spiperone / Q000494:pharmacology; D013237:Stereoisomerism
D000928:Antidepressive Agents; D015283:Citalopram; D008376:Maprotiline; D012701:Serotonin; C027299:hydroxymaprotilin; D013134:Spiperone; D007099:Imipramine; D009638:Norepinephrine