title: Biphasic effects of glycine on synaptic responses of the frog optic tectum in vitro.
abstract: Electrophysiological recordings from the in vitro amphibian optic tectum were used to study the action of bath-applied glycine (Gly) on synaptic transmission between optic tract fibres and tectal neurones. Gly enhanced synaptic field potentials (ED50 = 0.3 mM) and, when applied in concentrations greater than or equal to 1 mM subsequently blocked them. All these effects of Gly were antagonized by 0.2-1 microM strychnine. Recordings from optic tract afferent fibres indicated that Gly increased the amplitude of small submaximal compound action potentials while depressing those which were near maximal. It is suggested that Gly exerted a novel modulatory effect on synaptic transmission via a combination of pre- and postsynaptic sites of action.
authors.forename: L
authors.initials: L
authors.lastname: Sivilotti
authors.forename: A
authors.initials: A
authors.lastname: Nistri
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005998:Glycine / Q000494:pharmacology*; D066298:In Vitro Techniques; D010852:Picrotoxin / Q000494:pharmacology; D011896:Rana temporaria; D013477:Superior Colliculi / Q000187:drug effects* / Q000502:physiology; D013569:Synapses / Q000187:drug effects* / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D001640:Bicuculline; D005971:Glutamates; D018698:Glutamic Acid; D005998:Glycine; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid