Adenosine actions on CA1 pyramidal neurones in rat hippocampal slices

R. W. Greene, H. L. Haas

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100 Citations (Scopus)

Abstract

Intracellular recordings with a bridge amplifier of CA1 pyramidal neurones in vitro were employed to study the mechanisms of action of exogenously applied adenosine in the hippocampal slice preparation of the rat. Adenosine enhanced the calcium-dependent, long-duration after-hyperpolarization (a.h.p.) at least in part by a reduction in the rate of decay of the a.h.p. Both the reduced rate of decay and that of the control can be described with a single exponential. Antagonism of the calcium-dependent potassium current (and as a result, the a.h.p.) by bath application of CdCl2 or intracellular injection of EGTA (ethyleneglycolbis-(β-aminoethyl ether)N,N'-tetraacetic acid) did not reduce the adenosine-evoked hyperpolarization or decrease in input resistance. Similarly, TEA (tetraethylammonium), which antagonizes both the voltage- and calcium-sensitive, delayed, outward rectification, had no effect on the adenosine-evoked changes in resting membrane properties. Adenosine did not affect the early, transient, outward rectification. During exposure to 4-aminopyridine (4-AP) in concentrations sufficient to antagonize this early rectification, the changes in resting membrane properties evoked by adenosine were unaffected. We conclude that the enhancement of the a.h.p. and accommodation by adenosine may be mediated by a change in regulation of intracellular calcium. However, the mechanism responsible for the hyperpolarization and decrease in input resistance evoked by adenosine is both calcium and voltage insensitive. Thus, it appears distinct from that mediating the enhancement of the a.h.p. and accommodation.

Original languageEnglish (US)
Pages (from-to)119-127
Number of pages9
JournalJournal of Physiology
VolumeVOL. 366
StatePublished - 1985

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Pyramidal Cells
Adenosine
Calcium
Cadmium Chloride
4-Aminopyridine
Tetraethylammonium
Membranes
Egtazic Acid
Baths
Ether
Potassium
Injections
Acids

ASJC Scopus subject areas

  • Physiology

Cite this

Adenosine actions on CA1 pyramidal neurones in rat hippocampal slices. / Greene, R. W.; Haas, H. L.

In: Journal of Physiology, Vol. VOL. 366, 1985, p. 119-127.

Research output: Contribution to journalArticle

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