Abstract
Transient recovery (TR) of evoked synaptic potential during the late stage of hypoxic hypoglycemia (HH) insult was investigated in rat hippocampal slices using extracellular recording methods. TR was observed in association with a rapid deterioration of antidromic population spikes (aPSs) following HH insult. TR was not elicited in normoglycemic hypoxia (NH), in which a gradual and delayed deterioration of aPSs was noted. TR was not modulated by either Ca(2+)- or PKC-dependent processes. When a glycolytic inhibitor was added, NH resulted in a rapid deterioration of aPSs and prompted appearance of TR. TR was also seen in slices using lactate to generate energy via oxidative phosphorylation, when hypoxic conditions were subsequently created. Other pharmacological interventions that aimed to cause rapid deterioration of aPSs without depleting energy stores failed to reproduce TR. The evidence thus suggests that the underlying mechanisms of TR appearance during HH insult are highly correlated with rapid energy depletion.
MeSH terms
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Animals
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Chelating Agents / pharmacology
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Dantrolene / pharmacology
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Dose-Response Relationship, Drug
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Egtazic Acid / analogs & derivatives
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Egtazic Acid / pharmacology
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Electric Stimulation / methods
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Enzyme Inhibitors / pharmacology
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Excitatory Postsynaptic Potentials / drug effects
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Excitatory Postsynaptic Potentials / physiology
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Excitatory Postsynaptic Potentials / radiation effects
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Glucose / administration & dosage
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Hippocampus / cytology
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Hippocampus / drug effects
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Hippocampus / physiopathology
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Hypoglycemia / complications*
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Hypoxia / etiology
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Hypoxia / physiopathology*
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In Vitro Techniques
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Male
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Phorbol Esters / pharmacology
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Potassium Chloride / pharmacology
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Rats
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Rats, Sprague-Dawley
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Synapses / drug effects
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Synapses / physiology*
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Synapses / radiation effects
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Synaptic Transmission / drug effects
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Synaptic Transmission / physiology*
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Time Factors
Substances
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Chelating Agents
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Enzyme Inhibitors
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Phorbol Esters
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1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester
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Egtazic Acid
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Potassium Chloride
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Dantrolene
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Glucose