PMID- 17316998
OWN - NLM
STAT- MEDLINE
DCOM- 20070605
LR  - 20131121
IS  - 0304-3940 (Print)
IS  - 0304-3940 (Linking)
VI  - 414
IP  - 3
DP  - 2007 Mar 13
TI  - NMDA receptor-dependent high-frequency network oscillations (100-300 Hz) in rat 
      hippocampal slices.
PG  - 197-202
AB  - High-frequency oscillations (HFOs or ripples, >or=100 Hz) appear to be important 
      expressions of cortical circuits, characterizing physiological and pathological 
      functional states. Synaptic and non-synaptic mechanisms are involved in their 
      generation. This study shows that spontaneous N-methyl-D-aspartate receptor 
      (NMDAR) mediated potentials, recorded in dorsal and ventral hippocampal slices 
      perfused with magnesium-free medium and antagonists of non-NMDARs and GABA 
      receptors were associated with high-frequency oscillations (100-300 Hz), recorded 
      in all hippocampal subregions. Both CA3 and CA1 regions displayed HFOs at the 
      range of 180-300 Hz with oscillations in CA3 being significantly faster than in 
      CA1 (232+/-22 Hz, n=64 slices versus 206+/-18 Hz, n=24, P<0.001). Moreover, in 
      most of the slices (39/63) the CA1 network oscillated also at a lower frequency 
      (121.8+/-2.45 Hz). Simultaneous recordings showed that activity was most often 
      initiated in CA3 region; however, dentate gyrus and CA1 were potential sites of 
      generation as well. The incidence of spontaneous events was significantly higher 
      in ventral than in dorsal slices (20+/-1.6/min versus 5.4+/-0.3/min, P<0.001). 
      The competitive and non-competitive NMDAR antagonists, d-AP5 (50 microM) and MK 
      801 (50 microM), respectively abolished spontaneous activity. The gap-junction 
      blocker carbenoxolone significantly suppressed spontaneous activity in a 
      concentration-dependent manner. These data indicate that synaptic transmission 
      provided by solely NMDARs can sustain the generation of high-frequency network 
      oscillations, which display distinct characteristics in CA3 and CA1 subregions.
FAU - Papatheodoropoulos, Costas
AU  - Papatheodoropoulos C
AD  - University of Patras, Department of Physiology, Medical School, 26504 Rio, 
      Patras, Greece. cepapath@med.upatras.gr
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070220
PL  - Ireland
TA  - Neurosci Lett
JT  - Neuroscience letters
JID - 7600130
RN  - 0 (Anti-Ulcer Agents)
RN  - 0 (Excitatory Amino Acid Antagonists)
RN  - 0 (GABA Antagonists)
RN  - 0 (Receptors, N-Methyl-D-Aspartate)
RN  - 3KX376GY7L (Glutamic Acid)
RN  - MM6384NG73 (Carbenoxolone)
SB  - IM
MH  - Action Potentials/drug effects/physiology
MH  - Animals
MH  - Anti-Ulcer Agents/pharmacology
MH  - Biological Clocks/drug effects/*physiology
MH  - Carbenoxolone/pharmacology
MH  - Cortical Synchronization/drug effects
MH  - Excitatory Amino Acid Antagonists/pharmacology
MH  - GABA Antagonists/pharmacology
MH  - Gap Junctions/drug effects/metabolism
MH  - Glutamic Acid/metabolism
MH  - Hippocampus/drug effects/*metabolism
MH  - Male
MH  - Nerve Net/drug effects/*metabolism
MH  - Neural Pathways/drug effects/*metabolism
MH  - Organ Culture Techniques
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors/*metabolism
MH  - Synaptic Transmission/drug effects/*physiology
EDAT- 2007/02/24 09:00
MHDA- 2007/06/06 09:00
CRDT- 2007/02/24 09:00
PHST- 2006/07/26 00:00 [received]
PHST- 2006/10/12 00:00 [revised]
PHST- 2006/10/24 00:00 [accepted]
PHST- 2007/02/24 09:00 [pubmed]
PHST- 2007/06/06 09:00 [medline]
PHST- 2007/02/24 09:00 [entrez]
AID - S0304-3940(06)01146-3 [pii]
AID - 10.1016/j.neulet.2006.10.036 [doi]
PST - ppublish
SO  - Neurosci Lett. 2007 Mar 13;414(3):197-202. doi: 10.1016/j.neulet.2006.10.036. 
      Epub 2007 Feb 20.