Persistent enhancement of neuron-glia signaling mediated by increased extracellular K+ accompanying long-term synaptic potentiation.
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.
Ge
Woo-Ping
WP
Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Duan
Shumin
S
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D005110:Extracellular Space / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018408:Patch-Clamp Techniques / Q000379:methods; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
D002614:Chelating Agents; D018691:Excitatory Amino Acid Antagonists; D026902:Potassium Channel Blockers; D004533:Egtazic Acid; D015763:2-Amino-5-phosphonovalerate; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D011188:Potassium