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Kinetic and pharmacological examination of stimulation‐induced increases in synaptic efficacy in the chick ciliary ganglion
Author(s) -
Poage Robert E.,
Zengel Janet E.
Publication year - 1993
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890140111
Subject(s) - ciliary ganglion , stimulation , facilitation , ganglion , biophysics , superior cervical ganglion , chemistry , neuroscience , long term potentiation , neurotransmitter , anatomy , biology , central nervous system , biochemistry , receptor
We have characterized the kinetic and pharmacological properties of stimulation‐induced increases of synaptic efficacy in the embryonic chick ciliary ganglion. We found what appear to be four components of increased ganglionic efficacy with average time constants of decay of about 60 msec, 400 msec, 30 sec, and 200 sec. These time constants are similar to the those describing the decay of the four components of stimulation‐induced increases in neurotransmitter release characterized at other synapses. These components have been termed first and second components of facilitation, augmentation, and potentiation. We found that the addition of small amounts of Ba 2+ to the low Ca 2+ bathing solution led to an increase in the magnitude of the augmentation‐like component, whereas Sr 2+ enhanced the magnitude and time course of the component resembling the second component of facilitation. These effects of Ba 2+ and Sr 2+ are similar to the effects of these same divalent cations on augmentation and the second component of facilitation, respectively, at the frog neuromuscular junction and rabbit superior cervical ganglion. Based on these similar kinetic and pharmacological properties, we conclude that the four components of stimulation‐induced increases in release that have been described in other synaptic preparations also appear to be present in the chick ciliary ganglion. Published 1993 Wiley‐Liss, Inc.