2-3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline and syringaresinol

Many neuromodulating drugs acting on the nervous system originate from botanical sources. These plant-derived substances modulate the activity of receptors, ion channels, or transporters in neurons. Their properties make the substances useful for medicine and research. Here, we show that the plant lignan (+)-syringaresinol (SYR) suppresses excitatory synaptic transmission via presynaptic modulation. Bath application of SYR rapidly reduced the slopes of the field excitatory postsynaptic potentials (fEPSPs) at the hippocampal Schaffer collateral (SC)-CA1 synapse in a dose-dependent manner. SYR preferentially affected excitatory synapses, while inhibitory synaptic transmission remained unchanged. SYR had no effect on the conductance or the desensitization of AMPARs but increased the paired-pulse ratios of synaptic responses at short (20-200 ms) inter-stimulus intervals. These presynaptic changes were accompanied by a reduction of the readily releasable pool size. Pretreatment of hippocampal slices with the G

Topics: Animals; Central Nervous System Stimulants; Dose-Response Relationship, Drug; Electric Stimulation; Excitatory Amino Acid Antagonists; Female; Furans; Glutamic Acid; HEK293 Cells; Hippocampus; Humans; In Vitro Techniques; Lignans; Male; Mice; Patch-Clamp Techniques; Picrotoxin; Quinoxalines; Receptors, AMPA; Signal Transduction; Synaptic Transmission