title: Electrophysiological evidence for multiple glycinergic inputs to neonatal rat sympathetic preganglionic neurons in vitro.
abstract: The time pattern of glycinergic inhibitory postsynaptic currents (IPSCs) in sympathetic preganglionic neurons was studied in thin transverse spinal cord slices of neonatal (1-10 days postnatal) rats by means of the patchclamp technique. Three time patterns could be distinguished: (i) large events [mostly > 400 pA (30-36 degrees C)] occurring at regular intervals, (ii) small events occurring at irregular intervals, and (iii) small events occurring in transient (1.5-10 s), high-frequency (> 15 Hz) bursts of synaptic activity. The large regular events had uniform kinetics which was consistent with the idea of a proximal site of origin for all of these events. They were reversibly inhibited in amplitude and frequency by extracellular application of a high concentration of acetylcholine (200 microM) or the specific nicotinic acetylcholine receptor agonist dimethylphenylpiperazinium iodide (DMPP; 1 mM), but unaffected by glutamate (100 microM). IPSCs occurring in bursts had slower and less uniform kinetics, suggesting a more diverse site of origin. The frequency of events decreased during a burst. Similar bursts could be induced by extracellular application of glutamate receptor agonists. These results indicate that sympathetic pregnanglionic neurons in a thin, transverse spinal cord slice receive at least two different glycinergic inputs.
authors.affiliation: Institut de Physiologie Générale, Centre National de la Recherche Scientifique, Université Louis Pasteur, Strasbourg, France.
authors.forename: J
authors.initials: J
authors.lastname: Krupp
authors.forename: A
authors.initials: A
authors.lastname: Bordey
authors.forename: P
authors.initials: P
authors.lastname: Feltz
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001339:Autonomic Fibers, Preganglionic / Q000166:cytology / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005998:Glycine / Q000502:physiology*; D066298:In Vitro Techniques; D009474:Neurons / Q000502:physiology*; D018722:Nicotinic Agonists / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D051381:Rats; D013116:Spinal Cord / Q000502:physiology; D013564:Sympathetic Nervous System / Q000166:cytology / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D018690:Excitatory Amino Acid Agonists; D018722:Nicotinic Agonists; D005998:Glycine