Physiological effects of selective 5-HT1a and 5-HT1b ligands in rat hippocampus

comparison to 5-HT

M. Segal, E. C. Azmitia, P. M. Whitaker-Azmitia

Research output: Contribution to journalArticle

Abstract

The responses of CA1 neurons to topical application of serotonin (5-HT) and selective 5-HT1a and 5-HT1b agonists were examined with intracellular recording in the hippocampal slice. 5-HT produced a uniform hyperpolarizing response associated with an increase in K conductance as previously reported. In addition a marked reduction was reorded in slow after hyperpolarization (AHP) which follows a burst discharge. 8-OH-DPAT, ipsapirone and LY165, 163 partially mimicked the hyperpolarizing response to 5-HT when first applied to the slice. However, these 5-HT1a ligands antagonized responses to subsequent applications of 5-HT. Topical application of the 5-HT1b ligand TFMPP on the slice did not produce the direct or antagonistic action seen with the 5-HT1a ligands. It is suggested that the physiological response to 5-HT in the rat hippocampus is mediated by a 5-HT1a receptor. The currently available 5-HT1a ligands show a low agonist potential and a high antagonist action towards the responses of hippocampal neurons to 5-HT. Definite classification of the hyperpolarizing response to 5-HT awaits development of more specific ligands having a pure agonistic activity.

Original languageEnglish (US)
Pages (from-to)67-74
Number of pages8
JournalBrain Research
Volume502
Issue number1
DOIs
StatePublished - Nov 13 1989

Fingerprint

Hippocampus
Serotonin
Ligands
Neurons
8-Hydroxy-2-(di-n-propylamino)tetralin

Keywords

  • (+-)-8-Hydroxy-2-(di-n-propylamino) tetralin-HBr
  • 1-[3-trifluoromethyl)phenyl]-piperazine
  • 5-Hydroxytryptamine
  • Hippocampal slice

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Physiological effects of selective 5-HT1a and 5-HT1b ligands in rat hippocampus : comparison to 5-HT. / Segal, M.; Azmitia, E. C.; Whitaker-Azmitia, P. M.

In: Brain Research, Vol. 502, No. 1, 13.11.1989, p. 67-74.

Research output: Contribution to journalArticle

@article{242f298dacdf4578a15cc8041122ac80,
title = "Physiological effects of selective 5-HT1a and 5-HT1b ligands in rat hippocampus: comparison to 5-HT",
abstract = "The responses of CA1 neurons to topical application of serotonin (5-HT) and selective 5-HT1a and 5-HT1b agonists were examined with intracellular recording in the hippocampal slice. 5-HT produced a uniform hyperpolarizing response associated with an increase in K conductance as previously reported. In addition a marked reduction was reorded in slow after hyperpolarization (AHP) which follows a burst discharge. 8-OH-DPAT, ipsapirone and LY165, 163 partially mimicked the hyperpolarizing response to 5-HT when first applied to the slice. However, these 5-HT1a ligands antagonized responses to subsequent applications of 5-HT. Topical application of the 5-HT1b ligand TFMPP on the slice did not produce the direct or antagonistic action seen with the 5-HT1a ligands. It is suggested that the physiological response to 5-HT in the rat hippocampus is mediated by a 5-HT1a receptor. The currently available 5-HT1a ligands show a low agonist potential and a high antagonist action towards the responses of hippocampal neurons to 5-HT. Definite classification of the hyperpolarizing response to 5-HT awaits development of more specific ligands having a pure agonistic activity.",
keywords = "(+-)-8-Hydroxy-2-(di-n-propylamino) tetralin-HBr, 1-[3-trifluoromethyl)phenyl]-piperazine, 5-Hydroxytryptamine, Hippocampal slice",
author = "M. Segal and Azmitia, {E. C.} and Whitaker-Azmitia, {P. M.}",
year = "1989",
month = "11",
day = "13",
doi = "10.1016/0006-8993(89)90462-9",
language = "English (US)",
volume = "502",
pages = "67--74",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Physiological effects of selective 5-HT1a and 5-HT1b ligands in rat hippocampus

T2 - comparison to 5-HT

AU - Segal, M.

AU - Azmitia, E. C.

AU - Whitaker-Azmitia, P. M.

PY - 1989/11/13

Y1 - 1989/11/13

N2 - The responses of CA1 neurons to topical application of serotonin (5-HT) and selective 5-HT1a and 5-HT1b agonists were examined with intracellular recording in the hippocampal slice. 5-HT produced a uniform hyperpolarizing response associated with an increase in K conductance as previously reported. In addition a marked reduction was reorded in slow after hyperpolarization (AHP) which follows a burst discharge. 8-OH-DPAT, ipsapirone and LY165, 163 partially mimicked the hyperpolarizing response to 5-HT when first applied to the slice. However, these 5-HT1a ligands antagonized responses to subsequent applications of 5-HT. Topical application of the 5-HT1b ligand TFMPP on the slice did not produce the direct or antagonistic action seen with the 5-HT1a ligands. It is suggested that the physiological response to 5-HT in the rat hippocampus is mediated by a 5-HT1a receptor. The currently available 5-HT1a ligands show a low agonist potential and a high antagonist action towards the responses of hippocampal neurons to 5-HT. Definite classification of the hyperpolarizing response to 5-HT awaits development of more specific ligands having a pure agonistic activity.

AB - The responses of CA1 neurons to topical application of serotonin (5-HT) and selective 5-HT1a and 5-HT1b agonists were examined with intracellular recording in the hippocampal slice. 5-HT produced a uniform hyperpolarizing response associated with an increase in K conductance as previously reported. In addition a marked reduction was reorded in slow after hyperpolarization (AHP) which follows a burst discharge. 8-OH-DPAT, ipsapirone and LY165, 163 partially mimicked the hyperpolarizing response to 5-HT when first applied to the slice. However, these 5-HT1a ligands antagonized responses to subsequent applications of 5-HT. Topical application of the 5-HT1b ligand TFMPP on the slice did not produce the direct or antagonistic action seen with the 5-HT1a ligands. It is suggested that the physiological response to 5-HT in the rat hippocampus is mediated by a 5-HT1a receptor. The currently available 5-HT1a ligands show a low agonist potential and a high antagonist action towards the responses of hippocampal neurons to 5-HT. Definite classification of the hyperpolarizing response to 5-HT awaits development of more specific ligands having a pure agonistic activity.

KW - (+-)-8-Hydroxy-2-(di-n-propylamino) tetralin-HBr

KW - 1-[3-trifluoromethyl)phenyl]-piperazine

KW - 5-Hydroxytryptamine

KW - Hippocampal slice

UR - http://www.scopus.com/inward/record.url?scp=0024427935&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024427935&partnerID=8YFLogxK

U2 - 10.1016/0006-8993(89)90462-9

DO - 10.1016/0006-8993(89)90462-9

M3 - Article

VL - 502

SP - 67

EP - 74

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1

ER -