Theta-bursts induce a shift in reversal potentials for GABA-A receptor-mediated postsynaptic currents in rat hippocampal CA1 neurons.
Theta-burst stimulation of the stratum radiatum induces a negative shift in the reversal potential (RP) of gamma-aminobutyric acid (GABA)-ergic postsynaptic currents (PSCs) in hippocampal CA1 neurons in brain slices from rats of age groups 3-4 days, 6-9 days and 3-4 weeks. Furosemide reversed the shift in the RP. The amplitude of the evoked PSC appeared to increase following the theta-burst stimulation but this increase was secondary to the change in the RP. These results indicate that the RP for GABA-ergic PSCs undergoes an activity-dependent plasticity in not only neonatal but also adult neurons presumably through an up-regulation of a K(+)-Cl(-) co-transporter. This plasticity can have significant implications for neuronal network activity in the central nervous system. Furthermore, these results indicate that studies on GABA-ergic synaptic efficacy require a careful, parallel monitoring of the RP.
Xu
J-Y
JY
Neuroscience Research Laboratory, Department of Anesthesiology, Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, Vancouver, Canada V6T 1Z3.
Sastry
B R
BR
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation; D005665:Furosemide / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology* / Q000254:growth & development; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000502:physiology*; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000494:pharmacology; D013826:Theta Rhythm
D018756:GABA Antagonists; D011963:Receptors, GABA-A; D049994:Sodium Potassium Chloride Symporter Inhibitors; D005665:Furosemide; D001640:Bicuculline