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Titolo:
NEUROPHARMACOLOGICAL MECHANISMS UNDERLYING RHYTHMICAL DISCHARGE IN TRIGEMINAL INTERNEURONS DURING FICTIVE MASTICATION
Autore:
INOUE T; CHANDLER SH; GOLDBERG LJ;
Indirizzi:
UNIV CALIF LOS ANGELES,DEPT PHYSIOL SCI,2851 SLICHTER HALL LOS ANGELES CA 90024 UNIV CALIF LOS ANGELES,DEPT PHYSIOL SCI LOS ANGELES CA 90024 UNIV CALIF LOS ANGELES,SCH DENT LOS ANGELES CA 90024
Titolo Testata:
Journal of neurophysiology
fascicolo: 6, volume: 71, anno: 1994,
pagine: 2061 - 2073
SICI:
0022-3077(1994)71:6<2061:NMURDI>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
EXCITATORY AMINO-ACIDS; PONTOMEDULLARY RETICULAR-FORMATION; BULBAR RESPIRATORY NEURONS; ANESTHETIZED GUINEA-PIG; CENTRAL NERVOUS-SYSTEM; JAW-OPENING MOVEMENT; LAMPREY SPINAL-CORD; NON-NMDA RECEPTORS; MOTOR NUCLEUS; SYNAPTIC TRANSMISSION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
58
Recensione:
Indirizzi per estratti:
Citazione:
T. Inoue et al., "NEUROPHARMACOLOGICAL MECHANISMS UNDERLYING RHYTHMICAL DISCHARGE IN TRIGEMINAL INTERNEURONS DURING FICTIVE MASTICATION", Journal of neurophysiology, 71(6), 1994, pp. 2061-2073

Abstract

1. We have examined the effects of iontophoretic application of antagonists to excitatory amino acid (EAA) receptors, as well as gIycine and gamma-aminobutyric acid(GABA), on rhythmically active (RA) brain stem neurons during cortically induced masticatory activity (RMA) in the anesthetized guinea pig. Ten ofthese neurons were antidromically activated at latencies of 0.3-0.9 ms by stimulation of the trigeminal motornucleus (MoV). 2. RA neurons were divided into closer and opener typeaccording to the phase of activation during RMA. Iontophoretic application of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a specific non-N-methyl-D-aspartate (NMDA) receptor antagonist, suppressed discharge of both closer and opener type RA neurons during RMA. In contrast, iontophoretic application of -((1)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), a specific NMDA receptor antagonist, was not effective in suppressing discharge of most opener type RA neurons but did reduce activity of closer type RA neurons. 3. Spike discharge of most RA neurons was time locked to each cortical stimulus during RMA. Some of the RA neurons were activated at a short latency to short pulse train stimulation of the cortex in the absence of RMA. In most cases CNQX reduced such time-locked responses during RMA and greatly reduced discharge evoked by short pulse stimulation of the cortex in all cases. In contrast, CPP was not as effective in suppressing either the time-locked responses during RMA or the discharge evoked by short pulse train stimulation of the cortex. 4. D,L-Homocysteic acid (HCA) application produced low level maintained discharge in RA neurons before RMA induction. When RMA was evoked in combination with HCA, rhythmical burst discharges with distinct interburst periods during the opening phase of RMAwere observed in most closer type RA neurons. In contrast, during RMAin combination with HCA. application, opener type RA neurons showed burst discharges that were modulated during the RMA cycle but lacked distinct interburst periods during the closer phase of the cycle. 5. During application of strychnine (STR), a glycine antagonist, discharge of closer type RA neurons increased in the opener phase of RMA during continuous HCA application. In contrast, bicuculline methiodide (BIC), a GABA antagonist, did not increase unit discharge of closer type RA neurons in the opener phase of RMA. 6. It is concluded that closer typeRA neurons receive, alternatively, EAA-mediated excitatory and glycine-mediated inhibitory masticatory synaptic drive signals during RMA. For closer type RA neurons both non-NMDA and NMDA receptors participatein burst excitation during RMA. In contrast, opener type RA neurons receive mainly phasic excitatory masticatory drive signals mediated predominately by non-NMDA receptors during burst discharge of RMA with much less contribution of phasic inhibition during their interburst periods.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 01:39:31