Slow oscillations (</=1 Hz) mediated by GABAergic interneuronal networks in rat hippocampus.
Perfusion of rat brain slices with low millimole CsCl elicits slow oscillations of </=1 Hz in hippocampal CA1 pyramidal neurons. These oscillations are GABAA receptor-mediated hyperpolarizations that permit a coherent fire-pause pattern in a population of CA1 neurons. They can persist without the activation of ionotropic glutamate receptors but require adenosine-dependent inhibition of glutamate transmission. In response to external Cs+, multiple interneurons in the CA1 region display rhythmic discharges that correlate with the slow oscillations in CA1 pyramidal neurons. The interneuronal discharges arise spontaneously from the resting potential, and their rhythmicity is regulated by periodic, GABAA receptor-mediated hyperpolarizations. In addition, interneurons show periodic partial spikes and neurobiotin coupling, and applications of known gap junctional uncouplers interrupt the Cs+-induced slow rhythm in both CA1 pyramidal neurons and interneurons. We propose that these slow oscillations originate from a GABAergic interneuronal network that interacts through reciprocal inhibition and possibly gap junctional connection.
Zhang
Y
Y
Playfair Neuroscience Unit, Toronto Hospital Research Institute, University of Toronto, Toronto, Ontario, Canada M5T 2S8.
Perez Velazquez
J L
JL
Tian
G F
GF
Wu
C P
CP
Skinner
F K
FK
Carlen
P L
PL
Zhang
L
L
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000241:Adenosine / Q000502:physiology; D000367:Age Factors; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology; D002586:Cesium / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D017629:Gap Junctions / Q000737:chemistry / Q000502:physiology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006624:Hippocampus / Q000737:chemistry / Q000166:cytology*; D007395:Interneurons / Q000737:chemistry / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D010507:Periodicity; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000502:physiology; D013569:Synapses / Q000737:chemistry / Q000502:physiology; D013696:Temperature; D014970:Xanthines / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D001565:Benzoates; D002317:Cardiovascular Agents; D002712:Chlorides; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D011743:Pyrimidines; D011963:Receptors, GABA-A; D014970:Xanthines; C082246:ICI D2788; C079694:alpha-methyl-4-carboxyphenylglycine; D002586:Cesium; D005680:gamma-Aminobutyric Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; C051360:1,3-dipropyl-8-cyclopentylxanthine; C028019:cesium chloride; D000241:Adenosine; D005998:Glycine; D001640:Bicuculline