2-deoxyglucose induces LTP in layer I of rat somatosensory cortex in vitro.
Temporary replacement of glucose by 2-deoxyglucose (2-DG) induces a long-term potentiation (2-DG-LTP) of excitatory synaptic transmission in hippocampal slices. We therefore examined the effects of 2-DG on monosynaptic field excitatory postsynaptic potentials (fEPSPs) in slices of somatosensory cortex from rats. Monosynaptic fEPSPs were elicited in layer I by stimulating horizontal projections in the same layer. Replacement of glucose (10 mM) in the artificial cerebrospinal fluid with 10 mM 2-DG for 15-17 min produced a minor reduction (by 10-30%), followed by a sustained increase (by approximately 150%) in synaptic responses that could last for over 2 hours. Equimolar replacement of glucose with sucrose did not induce potentiation. The addition of 5 or even 2.5 mM glucose to 10 mM 2-DG largely suppressed the effects of 2-DG; but topically-applied GABA antagonists bicuculline and CGP 35348 did not prevent 2-DG-LTP. Unlike hippocampal 2-DG-LTP, neocortical 2-DG-LTP was: (1) not sensitive to 2-amino-5-phosphonopentanoic acid (AP5); and (2) usually not depotentiated by stimulation at 1 Hz. We conclude that 2-DG produces a robust and sustained increase in synaptic transmission in the neocortex through mechanisms that are independent of NMDA receptor activation.
Zhang
Z
Z
Anaesthesia Research Department, McGill University, QC, H3G 1Y6, Montréal, Canada.
Nguyen
K
K
Krnjević
K
K
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003847:Deoxyglucose / Q000494:pharmacology*; D004338:Drug Combinations; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D018756:GABA Antagonists / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D008297:Male; D019579:Neocortex / Q000187:drug effects / Q000502:physiology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D051381:Rats; D013003:Somatosensory Cortex / Q000187:drug effects* / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
D004338:Drug Combinations; D018756:GABA Antagonists; D009943:Organophosphorus Compounds; D015763:2-Amino-5-phosphonovalerate; C066430:CGP 35348; D003847:Deoxyglucose; D005947:Glucose; D001640:Bicuculline