@entity4053 at gamma and beta frequency are relevant to cognition. During this activity, excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) are generated rhythmically and synchronously and are thought to play an essential role in pacing the oscillations. The dynamic changes occurring to excitatory and inhibitory synaptic events during repetitive activation of synapses are therefore relevant to @entity4053 . To cast light on this issue in the @entity1399 region of the hippocampal slice, we used a train of stimuli, to the @entity655 , comprising 1 s at 40 Hz followed by 2--3 s at 10 Hz, to mimic the frequency pattern observed during @entity4053 . Whole cell current-clamp recordings from @entity1399 @entity528 revealed that individual stimuli at 40 Hz produced EPSPs riding on a slow biphasic hyperpolarizing-depolarizing waveform. EPSP amplitude initially increased; it then decreased concomitantly with the slow depolarization and with a large reduction in membrane resistance. During the subsequent 10-Hz train: the cells repolarized, EPSP amplitude and duration increased to above control, and no IPSPs were detected. In the presence of @entity1246 (A) receptor antagonists, the slow depolarization was blocked, and EPSPs of constant amplitude were generated by 10-Hz stimuli. Altering pyramidal cell membrane potential affected the time course of the slow depolarization, with the peak being reached earlier at more negative potentials. Glial recordings revealed that the trains were associated with extracellular @entity972 accumulation, but the time course of this event was slower than the neuronal depolarization. Numerical simulations showed that intracellular @entity2865 accumulation (due to massive GABAergic activation) can account for these observations. We conclude that synchronous activation of inhibitory synapses at gamma frequency causes a rapid @entity2865 accumulation in @entity528 , decreasing the efficacy of inhibitory potentials. The resulting transient disinhibition of the local network leads to a short-lasting facilitation of polysynaptic EPSPs. These results set constraints on the role that synchronous, rhythmic IPSPs may play in pacing oscillations at gamma frequency in the @entity1399 hippocampal region.

Dynamic modulation of excitation and inhibition during stimulation at gamma and beta frequencies in the XXXX hippocampal region.

@entity972 :: ('MESH:D011188', 'Chemical') :: ['potassium'] @entity1246 :: ('MESH:D005680', 'Chemical') :: ['GABA'] @entity1399 :: ('759', 'Gene') :: ['CA1'] @entity2865 :: ('CHEBI:17996', 'Chemical') :: ['chloride'] @entity4053 :: ('MESH:D007003', 'Disease') :: ['fast oscillations', 'Fast oscillations'] @entity655 :: ('MESH:C535504', 'Disease') :: ['pyramidal layer'] @entity528 :: ('MESH:D009410', 'Disease') :: ['pyramidal neurons']
@entity1399 :: (759,Gene) :: ['CA1']
