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Titolo:
Distinct subtypes of metabotropic glutamate receptors mediate differentialactions on excitability of spinal respiratory motoneurons
Autore:
Dong, XW; Feldman, JL;
Indirizzi:
Univ Calif Los Angeles, Dept Neurobiol, Syst Neurobiol Lab, Los Angeles, CA Univ Calif Los Angeles Los Angeles CA USA 90095 biol Lab, Los Angeles, CA Univ Calif Los Angeles, Dept Physiol Sci, Los Angeles, CA 90095 USA Univ Calif Los Angeles Los Angeles CA USA 90095 Los Angeles, CA 90095 USA
Titolo Testata:
JOURNAL OF NEUROSCIENCE
fascicolo: 13, volume: 19, anno: 1999,
pagine: 5173 - 5184
SICI:
0270-6474(19990701)19:13<5173:DSOMGR>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
INHIBITS CALCIUM CURRENTS; NEONATAL RAT HIPPOCAMPUS; SLOW SYNAPTIC RESPONSE; CENTRAL-NERVOUS-SYSTEM; GROUP-III MGLURS; PHRENIC MOTONEURONS; SIGNAL TRANSDUCTION; INSPIRATORY DRIVE; OLFACTORY-BULB; MOLECULAR CHARACTERIZATION;
Keywords:
metabotropic glutamate receptors; group-I subtype; group-II; group-III; synaptic transmission; presynaptic; postsynaptic; excitability; potassium channels; brainstem; spinal cord; phrenic motoneurons; respiration;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
80
Recensione:
Indirizzi per estratti:
Indirizzo: Feldman, JL Univ Calif Los Angeles, Dept Neurobiol, Syst Neurobiol Lab, Box 951763, Los Univ Calif Los Angeles Box 951763 Los Angeles CA USA 90095 Los
Citazione:
X.W. Dong e J.L. Feldman, "Distinct subtypes of metabotropic glutamate receptors mediate differentialactions on excitability of spinal respiratory motoneurons", J NEUROSC, 19(13), 1999, pp. 5173-5184

Abstract

Metabotropic glutamate receptors (mGluRs) modulate neuronal function by affecting excitability and altering synaptic transmission. We have shown thatthe mGluR agonist (1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid (1S,3R-ACPD) has multiple actions on phrenic motoneurons (PMNs), including reduction of inspiratory-modulated synaptic currents and an increase of neuronal excitability. We hypothesized that these actions were mediated by differentmGluR subtypes. We have now identified the involvement of mGluR subtypes and their roles in modulating the excitability of PMNs and the consequent inspiratory motor output in an in vitro neonatal rat brainstem-spinal cord preparation. Activation of postsynaptic group-I mGluRs increases PMN excitability, associated with the production of an inward current and a decrease inmembrane conductance, whereas activation of group-II or group-III mGluRs decreases PMN inspiratory-modulated synaptic current, probably via a presynaptic mechanism. To confirm further the distinction and the involvement of group-I and group-II/-III receptor subtypes affecting PMN excitability, we used the membrane permeable cAMP analog 8-bromo-cAMP (8-Br-cAMP) to elevate intracellular cAMP concentration to mask or occlude any effects mediated via the cAMP cascade. 8-Br-cAMP attenuated the reduction of the inspiratory-modulated activity of PMNs by both (S)-4-carboxy-3-hydroxyphenylglycine (4C3HPG) and L-(+)-2-amino-4-phosphonobutyric acid (L-AP4), agonists for group-II and group-III mGluRs, respectively, but did not affect the actions of 3,5-dihydroxyphenylglycine (DHPG), an agonist for group-I mGluRs. These threegroups of mGluRs are all endogenously activated during the inspiratory phase. We conclude that three groups of mGluRs are functionally expressed in the phrenic nucleus and that their activation modulates PMN excitability viadistinct mechanisms, with group-I acting at postsynaptic sites and group-II and group-III acting at presynaptic sites.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 11:43:39