Responses to repetitive afferent activity of rat solitary complex neurons isolated in brainstem slices.
The response of postsynaptic solitary complex neurons to repetitive stimulation (20-50 Hz) of the tractus solitarius were investigated by intracellular recordings in a brainstem slice preparation. Short duration stimuli (0.5 s) elicited increases in synaptic activity and short-term potentiation of synaptic potentials, both of which lasted approximately 1 min, plus a 10 s repolarization suppressed in the presence of glutamate ionotropic receptors antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM) and 2-D-amino-7-phosphonoheptanoic acid (AP7, 50 microM). Longer (5 s) stimuli elicited 2-10 min depolarizations accompanied by membrane resistance increases and unaffected by glutamate ionotropic receptors antagonists. Our study reveals several mechanisms by which rhythmic visceral afferents may exert a tonic control of postsynaptic solitary complex neurons.
Biologie Fonctionelle du Neurone, Institut Alfred Fessard, CNRS, Gif-sur-Yvette, France.
G
G
Fortin
J C
JC
Velluti
M
M
Denavit-Saubié
J
J
Champagnat
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D001933:Brain Stem / Q000166:cytology / Q000502:physiology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008526:Medulla Oblongata / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
D000596:Amino Acids; D000927:Anticonvulsants; D011810:Quinoxalines; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; C031231:2-amino-7-phosphonoheptanoic acid