TY - JOUR
T1 - Effect of nitric oxide on excitatory amino acid-evoked discharge of neurons in NTS
AU - Rodrigues Dias, Ana Carolina
AU - Colombari, Eduardo
AU - Mifflin, Steven W.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - N-methyl-D-aspartate (NMDA) and non-NMDA excitatory amino acid (EAA) receptor subtypes are involved in the integration of visceral afferent inputs within the nucleus of the solitary tract (NTS). Microinjection studies indicate interactions between nitric oxide (NO) and EAA receptors within the NTS. To examine these interactions at the single cell level, this study characterized the effects of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) and the NO donor 3-[2-hydroxy-2-nitroso-1-propylhydrazino]-1-propanamine (PAPA-NONOate) on the excitatory responses of vagus nerve (VN)-evoked NTS neurons to the activation of (RS)-α-amino-3-hydroxy-5- methyl-4-isoxazolepropionic acid (AMPA) and NMDA receptors in rats. Iontophoresis of L-NAME did not alter spontaneous or VN-evoked discharges, but significantly decreased the number of action potentials (APs) evoked by iontophoretic application of AMPA. The effects of L-NAME on NMDA-evoked discharge were variable; for the population, L-NAME did not change the number of APs evoked by NMDA. PAPA-NONOate enhanced the spontaneous discharge and the number of APs elicited by AMPA but not NMDA. Iontophoresis of the inactive enantiomers NG-nitro-D-arginine methyl ester and hydroxydiazenesulfonic acid 1-oxide disodium salt had no effect on AMPA-evoked discharge. Our data suggest that NO facilitates AMPA-mediated neuronal transmission within the NTS.
AB - N-methyl-D-aspartate (NMDA) and non-NMDA excitatory amino acid (EAA) receptor subtypes are involved in the integration of visceral afferent inputs within the nucleus of the solitary tract (NTS). Microinjection studies indicate interactions between nitric oxide (NO) and EAA receptors within the NTS. To examine these interactions at the single cell level, this study characterized the effects of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) and the NO donor 3-[2-hydroxy-2-nitroso-1-propylhydrazino]-1-propanamine (PAPA-NONOate) on the excitatory responses of vagus nerve (VN)-evoked NTS neurons to the activation of (RS)-α-amino-3-hydroxy-5- methyl-4-isoxazolepropionic acid (AMPA) and NMDA receptors in rats. Iontophoresis of L-NAME did not alter spontaneous or VN-evoked discharges, but significantly decreased the number of action potentials (APs) evoked by iontophoretic application of AMPA. The effects of L-NAME on NMDA-evoked discharge were variable; for the population, L-NAME did not change the number of APs evoked by NMDA. PAPA-NONOate enhanced the spontaneous discharge and the number of APs elicited by AMPA but not NMDA. Iontophoresis of the inactive enantiomers NG-nitro-D-arginine methyl ester and hydroxydiazenesulfonic acid 1-oxide disodium salt had no effect on AMPA-evoked discharge. Our data suggest that NO facilitates AMPA-mediated neuronal transmission within the NTS.
KW - (RS)-α- amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
KW - N-methyl-D-aspartate
KW - Nucleus of the solitary tract
KW - Vagus nerve stimulation
UR - http://www.scopus.com/inward/record.url?scp=0037235244&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00037.2002
DO - 10.1152/ajpheart.00037.2002
M3 - Article
C2 - 12485819
AN - SCOPUS:0037235244
SN - 0363-6135
VL - 284
SP - H234-H240
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 1 53-1
ER -