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Effects of dopamine on the superior cervical ganglion of the rabbit
Author(s) -
Dun N.,
Nishi S.
Publication year - 1974
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1974.sp010560
Subject(s) - dopamine , excitatory postsynaptic potential , chemistry , acetylcholine , hyperpolarization (physics) , phenoxybenzamine , superior cervical ganglion , neurotransmission , membrane potential , dopaminergic , endocrinology , biophysics , medicine , neuroscience , inhibitory postsynaptic potential , biology , propranolol , biochemistry , stereochemistry , receptor , nuclear magnetic resonance spectroscopy
1. The effects of dopamine on isolated rabbit superior cervical ganglion were investigated with intracellular recording techniques. 2. Dopamine (10 −5 ‐10 −3 M ) depressed the amplitude of the excitatory post‐synaptic potential (e.p.s.p.) and blocked impulse transmission. 3. Dopamine (10 −4 M ) induced a slight (2–5 mV) post‐synaptic hyperpolarization without altering membrane conductance. 4. The post‐synaptic membrane sensitivity to acetylcholine (ACh) applied iontophoretically was not affected by dopamine. 5. Dopamine decreased the frequency of miniature excitatory post‐synaptic potentials (m.e.p.s.p.s) in a high K + solution, with no change in the amplitude of m.e.p.s.p.s. 6. Dopamine reduced the quantal content of the e.p.s.p. in a low Ca 2+ and high Mg 2+ solution, but had no effect on the quantal size. 7. The ganglionic blocking effect of dopamine was antagonized by phenoxybenzamine, but not by propranolol. 8. The results show that the ganglionic depressant effect of dopamine is exerted primarily through an alpha‐adrenoceptive site at the presynaptic nerve terminal.