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Titolo:
Chemical hypoxia in hippocampal pyramidal cells affects membrane potentialdifferentially depending on resting potential
Autore:
Englund, M; Hyllienmark, L; Brismar, T;
Indirizzi:
Karolinska Hosp, Dept Clin Neurophysiol, SE-17176 Stockholm, Sweden Karolinska Hosp Stockholm Sweden SE-17176 ol, SE-17176 Stockholm, Sweden
Titolo Testata:
NEUROSCIENCE
fascicolo: 1, volume: 106, anno: 2001,
pagine: 89 - 94
SICI:
0306-4522(2001)106:1<89:CHIHPC>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
SENSITIVE POTASSIUM CHANNELS; NEURONS IN-VITRO; METABOLIC INHIBITION; RAT HIPPOCAMPUS; CA1 NEURONS; GRANULE CELLS; BRAIN-SLICES; HYPERPOLARIZATION; CONDUCTANCE; RESPONSES;
Keywords:
brain slice; CA1 region; cyanide; patch clamp; rat;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
25
Recensione:
Indirizzi per estratti:
Indirizzo: Englund, M Karolinska Hosp, Dept Clin Neurophysiol, R2 01, SE-17176 Stockholm, Sweden Karolinska Hosp R2 01 Stockholm Sweden SE-17176 ckholm, Sweden
Citazione:
M. Englund et al., "Chemical hypoxia in hippocampal pyramidal cells affects membrane potentialdifferentially depending on resting potential", NEUROSCIENC, 106(1), 2001, pp. 89-94

Abstract

The aim of the present study was to analyze the effect of chemical hypoxia(cyanide) on the membrane potential of hippocampal CAI neurons and to elucidate the reason for previously found differences in the reaction to hypoxia in these cells. Recordings were performed in brain slices from 8-19-day-old rats with whole-cell patch clamp on cells identified with near-infrared video microscopy. Cyanide (0.1-2.0 mM) caused different responses dependingon the resting potential of the cells: hyperpolarization (or an initial depolarization followed by hyperpolarization) was generally seen in cells with less negative resting potential (-56 +/-6.1 mV), and depolarization in cells with more negative resting potential (-62 +/-3.4 mV). After 10 min in cyanide the membrane potential in all cells had reached approximately the same level (-62 +/-5.8 m.V), the direction and size of the voltage response having an inverse linear relation to the resting potential (k= -0.98, r=0.71). The direction of the cyanide response was not reversed by current injection (depolarization by 12 mV) in cells with more negative resting potential(-60 +/-2.8 mV). Wash out of cyanide caused hyperpolarization in 70% of the cells. Presence of ouabain (2 muM) resulted in pronounced depolarization during cyanide perfusion, and potentiated the hyperpolarization during washout indicating that this part of the effect is not dependent on a reactivation of the Na/K pump. In conclusion, chemical hypoxia with cyanide changes the membrane potential in CAI cells in size and direction depending on the original resting potential of the cells. The present findings suggested that cyanide activated not only K+ channels but in addition increased a Na+ current which has a more positive equilibrium potential. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/20 alle ore 19:14:47