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Titolo:
INTRINSIC BURST GENERATION OF PREINSPIRATORY NEURONS IN THE MEDULLA OF BRAIN-STEM-SPINAL CORD PREPARATIONS ISOLATED FROM NEWBORN RATS
Autore:
ONIMARU H; ARATA A; HOMMA I;
Indirizzi:
SHOWA UNIV,SCH MED,DEPT PHYSIOL,SHINAGAWA KU,1-5-8 HATANODAI TOKYO 142 JAPAN
Titolo Testata:
Experimental Brain Research
fascicolo: 1, volume: 106, anno: 1995,
pagine: 57 - 68
SICI:
0014-4819(1995)106:1<57:IBGOPN>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
RESPIRATORY RHYTHM GENERATOR; ELECTRO-PHYSIOLOGICAL PROPERTIES; MAMMALIAN CEREBELLAR SLICES; MAMMILLARY COMPLEX INVITRO; WHOLE-CELL; INSPIRATORY NEURONS; VENTROLATERAL MEDULLA; CALCIUM CURRENT; NEONATAL RAT; MECHANISMS;
Keywords:
RESPIRATORY RHYTHM; RESPIRATORY NEURONS; PACEMAKER NEURONS; PERFORATED PATCH; NYSTATIN; RAT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
40
Recensione:
Indirizzi per estratti:
Citazione:
H. Onimaru et al., "INTRINSIC BURST GENERATION OF PREINSPIRATORY NEURONS IN THE MEDULLA OF BRAIN-STEM-SPINAL CORD PREPARATIONS ISOLATED FROM NEWBORN RATS", Experimental Brain Research, 106(1), 1995, pp. 57-68

Abstract

In brainstem-spinal cord preparations isolated from newborn rats, intrinsic burst-generating properties of preinspiratory (Pre-I) neurons in the rostral ventrolateral medulla, which have been suggested to be primary respiratory rhythm-generating neurons, were studied by ''perforated'' whole-cell recordings using the antibiotic nystatin. Nystatin causes small pores to be formed in the cells, through which pass small monovalent ions. For blockade of chemical synaptic transmission, perfusate Ca2+ concentration was lowered to 0.2 mM and the Mg2+ concentration was increased to 5 mM. In low-Ca2+, high-Mg2+ solution (referred tohere as ''low Ca''), 10 of 55 Pre-I neurons generated rhythmic bursts(burst type), 14 fired tonically (tonic type), and 31 were silent (silent type). Burst-type neurons showed periodic depolarization of 5-12 mV in low Ca, at a rate of 12+/-6.5/min. Hyperpolarization of the membrane caused decrease in or disappearance of the periodic depolarization and prolongation of the cycle period. Thus, the burst generations were voltage dependent. The firing frequency of tonic-type neurons was 2.3+/-1.6 Hz and was decreased by hyperpolarization. In 6 of these neurons, the firing patterns changed to burst patterns during continuous hyperpolar ization. Membrane depolarization by continuous outward current injection into some silent-type neurons (3 of II tested) induced bursting activity. Activity of C4 and Pre-I neurons was completely silent with O.1-1 mu M tetrodotoxin (TTX) added to the standard perfusate. In low Ca, burst-type neurons (n=3) were also silent with I mu M TTX perfusion. Inspiratory neurons either became silent (n=4) or fired tonically (n=1) in low Ca. The present study by ''perforated'' whole-cell recordings confirmed that some Pre-I neurons possess intrinsic burst-generating properties, which were not attributable to phasic synaptic inputs.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 02:28:25