Abstract
Neuron-glia signaling is important for neural development and functions. This signaling may be regulated by neuronal activity and undergo modification similar to long-term potentiation (LTP) of neuronal synapses, a hallmark of neuronal plasticity. We found that tetanic stimulation of Schaffer collaterals (Sc) in the hippocampus that induced LTP in neurons also resulted in LTP-like persistent elevation of Sc-evoked slow depolarization in perisynaptic astrocytes. The elevated slow depolarization in astrocytes was abolished by NMDA receptor antagonist and K(+) channel inhibitors, but not by Ca(2+) chelator BAPTA loaded in the recorded astrocytes, suggesting involvement of an increased extracellular K(+) accumulation accompanying LTP of neuronal synapses. The increased K(+) accumulation and astrocyte depolarization after LTP induction may reduce the efficiency of glial glutamate transporters, which may contribute to the enhanced synaptic efficacy. The neuronal activity-induced persistent enhancement of neuron-glia signaling may thus have important physiological relevance.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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2-Amino-5-phosphonovalerate / pharmacology
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Animals
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Animals, Newborn
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Chelating Agents / pharmacology
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Dose-Response Relationship, Drug
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Drug Interactions
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Egtazic Acid / analogs & derivatives
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Egtazic Acid / pharmacology
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Electric Stimulation
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Excitatory Amino Acid Antagonists / 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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Extracellular Space / metabolism*
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Hippocampus / cytology
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In Vitro Techniques
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Long-Term Potentiation / drug effects
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Long-Term Potentiation / physiology*
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Long-Term Potentiation / radiation effects
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Neuroglia / drug effects
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Neuroglia / physiology*
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Neuroglia / radiation effects
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Neurons / drug effects
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Neurons / physiology*
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Neurons / radiation effects
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Patch-Clamp Techniques / methods
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Potassium / metabolism*
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Potassium / pharmacology
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Potassium Channel Blockers / pharmacology
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Rats
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Signal Transduction / drug effects
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Signal Transduction / physiology*
Substances
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Chelating Agents
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Excitatory Amino Acid Antagonists
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Potassium Channel Blockers
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Egtazic Acid
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2-Amino-5-phosphonovalerate
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1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
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Potassium