Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability

H. R. Olpe, K. Klebs, E. Küng, P. Campiche, A. Glatt, R. Ortmann, F. D'Amato, M. F. Pozza, C. Mondadori

Research output: Contribution to journalArticle

Abstract

The actions of cholinomimetics and of physostigmine were tested on two parameters reflecting hippocampal activity, namely θ activity and pyramidal cell excitability. In rats pretreated with methylscopolamine and anaesthetized with urethane i.v. administration of the cholinomimetics oxotremorine and arecoline and the cholinesterase blocker physostigmine evoked θ wave activity in the hippocampus, which was blocked by scopolamine. Spectral analysis demonstrated that the frequency of the θ waves induced was dose-related, ranging from about 3 Hz to between 5 and 6 Hz. θ Activity could not be induced by arecoline in animals with large septal lesions. Pyramidal cell excitability is known to be increased by endogenous acetylcholine released from cholinergic fibres. In the present study, however, i.v. injections of oxotremorine, arecoline and physostigmine in doses that induce θ activity diminished the excitability of CA1 pyramidal cells in a dose-dependent manner, as judged by the reduction in the amplitude of the population spike and the dendritic epsp. These depressant effects were attenuated by scopolamine but not by methylscopolamine. The depressant effect of arecoline was attenuated in rats with extensive lesions in the medial septal area. The present findings demonstrate that exogenously administered cholinomimetics only partly mimic the action of endogenous acetylcholine in the hippocampus. The central sites of action of exogenously administered cholinomimetics for mediation of θ activity and alteration of pyramidal cell excitability remain to be elucidated.

Original languageEnglish
Pages (from-to)275-283
Number of pages9
JournalEuropean Journal of Pharmacology
Volume142
Issue number2
DOIs
Publication statusPublished - Oct 13 1987

Fingerprint

Arecoline
Pyramidal Cells
Cholinergic Agents
Physostigmine
Oxotremorine
Scopolamine Hydrobromide
Acetylcholine
Hippocampus
Cholinergic Fibers
Septum of Brain
Urethane
Cholinesterases
Injections
Population

Keywords

  • Cholinesterase blockers
  • Cholinomimetics
  • Hippocampus
  • Pyramidal cells
  • θ Rhythm

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Pharmacology

Cite this

Olpe, H. R., Klebs, K., Küng, E., Campiche, P., Glatt, A., Ortmann, R., ... Mondadori, C. (1987). Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability. European Journal of Pharmacology, 142(2), 275-283. https://doi.org/10.1016/0014-2999(87)90117-8

Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability. / Olpe, H. R.; Klebs, K.; Küng, E.; Campiche, P.; Glatt, A.; Ortmann, R.; D'Amato, F.; Pozza, M. F.; Mondadori, C.

In: European Journal of Pharmacology, Vol. 142, No. 2, 13.10.1987, p. 275-283.

Research output: Contribution to journalArticle

Olpe, HR, Klebs, K, Küng, E, Campiche, P, Glatt, A, Ortmann, R, D'Amato, F, Pozza, MF & Mondadori, C 1987, 'Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability', European Journal of Pharmacology, vol. 142, no. 2, pp. 275-283. https://doi.org/10.1016/0014-2999(87)90117-8
Olpe, H. R. ; Klebs, K. ; Küng, E. ; Campiche, P. ; Glatt, A. ; Ortmann, R. ; D'Amato, F. ; Pozza, M. F. ; Mondadori, C. / Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability. In: European Journal of Pharmacology. 1987 ; Vol. 142, No. 2. pp. 275-283.
@article{4db7aa0ad11e406d8643891ccfd13c14,
title = "Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability",
abstract = "The actions of cholinomimetics and of physostigmine were tested on two parameters reflecting hippocampal activity, namely θ activity and pyramidal cell excitability. In rats pretreated with methylscopolamine and anaesthetized with urethane i.v. administration of the cholinomimetics oxotremorine and arecoline and the cholinesterase blocker physostigmine evoked θ wave activity in the hippocampus, which was blocked by scopolamine. Spectral analysis demonstrated that the frequency of the θ waves induced was dose-related, ranging from about 3 Hz to between 5 and 6 Hz. θ Activity could not be induced by arecoline in animals with large septal lesions. Pyramidal cell excitability is known to be increased by endogenous acetylcholine released from cholinergic fibres. In the present study, however, i.v. injections of oxotremorine, arecoline and physostigmine in doses that induce θ activity diminished the excitability of CA1 pyramidal cells in a dose-dependent manner, as judged by the reduction in the amplitude of the population spike and the dendritic epsp. These depressant effects were attenuated by scopolamine but not by methylscopolamine. The depressant effect of arecoline was attenuated in rats with extensive lesions in the medial septal area. The present findings demonstrate that exogenously administered cholinomimetics only partly mimic the action of endogenous acetylcholine in the hippocampus. The central sites of action of exogenously administered cholinomimetics for mediation of θ activity and alteration of pyramidal cell excitability remain to be elucidated.",
keywords = "Cholinesterase blockers, Cholinomimetics, Hippocampus, Pyramidal cells, θ Rhythm",
author = "Olpe, {H. R.} and K. Klebs and E. K{\"u}ng and P. Campiche and A. Glatt and R. Ortmann and F. D'Amato and Pozza, {M. F.} and C. Mondadori",
year = "1987",
month = "10",
day = "13",
doi = "10.1016/0014-2999(87)90117-8",
language = "English",
volume = "142",
pages = "275--283",
journal = "European Journal of Pharmacology",
issn = "0014-2999",
publisher = "Elsevier",
number = "2",

}

TY - JOUR

T1 - Cholinomimetics induce θ rhythm and reduce hippocampal pyramidal cell excitability

AU - Olpe, H. R.

AU - Klebs, K.

AU - Küng, E.

AU - Campiche, P.

AU - Glatt, A.

AU - Ortmann, R.

AU - D'Amato, F.

AU - Pozza, M. F.

AU - Mondadori, C.

PY - 1987/10/13

Y1 - 1987/10/13

N2 - The actions of cholinomimetics and of physostigmine were tested on two parameters reflecting hippocampal activity, namely θ activity and pyramidal cell excitability. In rats pretreated with methylscopolamine and anaesthetized with urethane i.v. administration of the cholinomimetics oxotremorine and arecoline and the cholinesterase blocker physostigmine evoked θ wave activity in the hippocampus, which was blocked by scopolamine. Spectral analysis demonstrated that the frequency of the θ waves induced was dose-related, ranging from about 3 Hz to between 5 and 6 Hz. θ Activity could not be induced by arecoline in animals with large septal lesions. Pyramidal cell excitability is known to be increased by endogenous acetylcholine released from cholinergic fibres. In the present study, however, i.v. injections of oxotremorine, arecoline and physostigmine in doses that induce θ activity diminished the excitability of CA1 pyramidal cells in a dose-dependent manner, as judged by the reduction in the amplitude of the population spike and the dendritic epsp. These depressant effects were attenuated by scopolamine but not by methylscopolamine. The depressant effect of arecoline was attenuated in rats with extensive lesions in the medial septal area. The present findings demonstrate that exogenously administered cholinomimetics only partly mimic the action of endogenous acetylcholine in the hippocampus. The central sites of action of exogenously administered cholinomimetics for mediation of θ activity and alteration of pyramidal cell excitability remain to be elucidated.

AB - The actions of cholinomimetics and of physostigmine were tested on two parameters reflecting hippocampal activity, namely θ activity and pyramidal cell excitability. In rats pretreated with methylscopolamine and anaesthetized with urethane i.v. administration of the cholinomimetics oxotremorine and arecoline and the cholinesterase blocker physostigmine evoked θ wave activity in the hippocampus, which was blocked by scopolamine. Spectral analysis demonstrated that the frequency of the θ waves induced was dose-related, ranging from about 3 Hz to between 5 and 6 Hz. θ Activity could not be induced by arecoline in animals with large septal lesions. Pyramidal cell excitability is known to be increased by endogenous acetylcholine released from cholinergic fibres. In the present study, however, i.v. injections of oxotremorine, arecoline and physostigmine in doses that induce θ activity diminished the excitability of CA1 pyramidal cells in a dose-dependent manner, as judged by the reduction in the amplitude of the population spike and the dendritic epsp. These depressant effects were attenuated by scopolamine but not by methylscopolamine. The depressant effect of arecoline was attenuated in rats with extensive lesions in the medial septal area. The present findings demonstrate that exogenously administered cholinomimetics only partly mimic the action of endogenous acetylcholine in the hippocampus. The central sites of action of exogenously administered cholinomimetics for mediation of θ activity and alteration of pyramidal cell excitability remain to be elucidated.

KW - Cholinesterase blockers

KW - Cholinomimetics

KW - Hippocampus

KW - Pyramidal cells

KW - θ Rhythm

UR - http://www.scopus.com/inward/record.url?scp=0023574209&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023574209&partnerID=8YFLogxK

U2 - 10.1016/0014-2999(87)90117-8

DO - 10.1016/0014-2999(87)90117-8

M3 - Article

C2 - 3691642

AN - SCOPUS:0023574209

VL - 142

SP - 275

EP - 283

JO - European Journal of Pharmacology

JF - European Journal of Pharmacology

SN - 0014-2999

IS - 2

ER -