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Purinergic Modulation of Hippocampal Acetylcholine Release Involves α‐Dendrotoxin‐Sensitive Potassium Channels
Author(s) -
Benishin Christina G.
Publication year - 1990
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1990.tb05799.x
Subject(s) - oxotremorine , purinergic receptor , muscarinic acetylcholine receptor , chemistry , acetylcholine , agonist , muscarinic agonist , biophysics , potassium channel , endocrinology , receptor , biology , biochemistry
Modulation of acetylcholine (ACh) release from superfused hippocampal slices was examined when the release of ACh was stimulated by exposure of slices to elevated K + concentration. Evoked release was not sensitive to inhibition by 0.1 μ M tetrodotoxin, but it could be inhibited in a dose‐dependent manner by a muscarinic agonist (10–100 n M oxotremorine) and a purinergic agonist (10–100 n M 2‐chloroadenosine). The α‐dendrotoxin (100 n M ), which selectively blocks voltage‐gated inactivating K + channels in nerve endings, did not affect the release of ACh under resting or depolarized conditions. However, α‐dendrotoxin reduced the 2‐chloroadenosine‐induced inhibition of release, but did not alter the oxotremorine‐induced inhibition. These results suggest that an α‐dendrotoxin‐sensitive K + channel may be activated as an obligatory step in the modulation of ACh release by presynaptic purinergic receptor activation, but not in the modulation by presynaptic muscarinic receptors.