PMID: 1315607Feb 21, 1992Paper

Suppression of presynaptic calcium currents by hypoxia in hippocampal tissue slices

Brain Research
J Young, G G Somjen

Abstract

We tested the hypothesis that suppression of inward calcium current in presynaptic terminals is the cause of failure of synaptic transmission early during cerebral hypoxia. Postsynaptic responses in CA1 zone of hippocampal tissue slices were blocked either by the combined administration of 6,7-dinitroquinoxaline-2,3-dione (DNQX) and 3-((+-)-2-carboxypiperazine-4-yl)-propyl-1-phosphonic acid (CPP) or by lowering extracellular calcium concentration ([Ca2+]o). Repetitive orthodromic activation of central neurons caused transient decrease of [Ca2+]o (measured by ion selective microelectrodes) in neuropil, attributable to influx of Ca2+ in presynaptic terminals. Presynaptic [Ca2+]o responses were rapidly and reversibly suppressed when oxygen was withdrawn from hippocampal tissue slices. The 'resting' baseline level of [Ca2+]o declined at first gradually, then precipitously as in spreading depression (SD). Presynaptic volleys during high frequency train stimulation were also depressed somewhat before SD began. We conclude that (1) presynaptic Ca2+ currents fail during hypoxia, perhaps because 'resting' intracellular free Ca2+ activity is increased and, in part, also because of partial failure of presynaptic impulse conduction; (2) th...Continue Reading

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Citations

Dec 31, 1993·Brain Research·G G SomjenW J Wadman
Jul 6, 2000·European Journal of Pharmacology·T W Stone
May 29, 1998·Brain Research. Developmental Brain Research·K AliciU Heinemann
Oct 1, 1995·British Journal of Pharmacology·M D CroningN R Newberry
Aug 8, 2008·The Journal of Neuroscience : the Official Journal of the Society for Neuroscience·Robert M DietzClaude W Shuttleworth
Mar 4, 2008·Neuropharmacology·Kresimir Krnjević
May 7, 2009·Journal of Neurochemistry·Robert M DietzC William Shuttleworth
Apr 1, 1997·Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia·R L Martin
Feb 25, 2014·Brain Research·Jeannette HofmeijerJoost le Feber
May 4, 2002·Stroke; a Journal of Cerebral Circulation·Hayrunnisa BolayTurgay Dalkara
Dec 31, 2011·Stroke; a Journal of Cerebral Circulation·Jeannette Hofmeijer, Michel J A M van Putten
Mar 1, 1994·Journal of Neurochemistry·M J NealJ Hogg
Dec 15, 2019·Progress in Neurobiology·Adrien E SchrammStéphane Charpier

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