RRC ID 33266
Author Aivar P, Valero M, Bellistri E, Menendez de la Prida L.
Title Extracellular calcium controls the expression of two different forms of ripple-like hippocampal oscillations.
Journal J Neurosci
Abstract Hippocampal high-frequency oscillations (HFOs) are prominent in physiological and pathological conditions. During physiological ripples (100-200 Hz), few pyramidal cells fire together coordinated by rhythmic inhibitory potentials. In the epileptic hippocampus, fast ripples (>200 Hz) reflect population spikes (PSs) from clusters of bursting cells, but HFOs in the ripple and the fast ripple range are vastly intermixed. What is the meaning of this frequency range? What determines the expression of different HFOs? Here, we used different concentrations of Ca(2+) in a physiological range (1-3 mM) to record local field potentials and single cells in hippocampal slices from normal rats. Surprisingly, we found that this sole manipulation results in the emergence of two forms of HFOs reminiscent of ripples and fast ripples recorded in vivo from normal and epileptic rats, respectively. We scrutinized the cellular correlates and mechanisms underlying the emergence of these two forms of HFOs by combining multisite, single-cell and paired-cell recordings in slices prepared from a rat reporter line that facilitates identification of GABAergic cells. We found a major effect of extracellular Ca(2+) in modulating intrinsic excitability and disynaptic inhibition, two critical factors shaping network dynamics. Moreover, locally modulating the extracellular Ca(2+) concentration in an in vivo environment had a similar effect on disynaptic inhibition, pyramidal cell excitability, and ripple dynamics. Therefore, the HFO frequency band reflects a range of firing dynamics of hippocampal networks.
Volume 34(8)
Pages 2989-3004
Published 2014-2-19
DOI 10.1523/JNEUROSCI.2826-13.2014
PII 34/8/2989
PMID 24553939
PMC PMC6608517
MeSH Action Potentials / physiology Animals Calcium / pharmacology Calcium / physiology* Calcium Signaling / physiology* Data Interpretation, Statistical Electrophysiological Phenomena / physiology Excitatory Postsynaptic Potentials / physiology Extracellular Space / physiology Female Hippocampus / physiology* In Vitro Techniques Interneurons / physiology Male Membrane Potentials / physiology Patch-Clamp Techniques Pyramidal Cells / physiology Rats Rats, Wistar Synaptic Transmission / physiology gamma-Aminobutyric Acid / physiology
IF 5.674
Times Cited 35
Rats W-Tg(Slc32a1-YFP*)1Yyan(strainID=905)