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Slow periodic events and their transition to gamma oscillations in the entorhinal cortex of the isolated Guinea pig brain.
- Source :
-
Journal of neurophysiology [J Neurophysiol] 2003 Jul; Vol. 90 (1), pp. 39-46. - Publication Year :
- 2003
-
Abstract
- Slow (<1 Hz) periodic activity is a distinctive discharge pattern observed in different cortical and sub-cortical structures during sleep and anesthesia. By performing field and cellular recordings, we demonstrated that slow periodic events (0.02-0.4 Hz) are spontaneously generated in the entorhinal cortex of the in vitro isolated whole brain of the guinea pig. These events were characterized by gradually developing runs of low-amplitude (50-300 microV), high-frequency (25-70 Hz) oscillations superimposed on a slow potential that lasted 1-3 s. Both slow and fast components showed a phase reversal in the superficial layers. In layer II-III entorhinal neurons, the slow periodic events correlated to a slowly developing depolarizing envelope capped by subthreshold membrane potential oscillations and action potential discharge. Slow periodic field events propagated tangentially across the entorhinal cortex and could be triggered by stimulation of superficial associative fibers, suggesting that they were generated by and propagated via network interactions in the superficial layers. Slow periodic events were reversibly abolished by muscarinic excitation elicited by carbachol (50 microM) that promoted intracellular membrane potential depolarization associated with continuous fast oscillatory activity in the gamma frequency range. These results suggest that, as proposed in vivo, activity changes in the entorhinal cortex of the in vitro isolated guinea-pig brain reflect different activation states that are under cholinergic control.
- Subjects :
- Acetylcholine physiology
Animals
Brain physiology
Carbachol pharmacology
Cholinergic Agonists pharmacology
Electrophysiology
Entorhinal Cortex drug effects
Guinea Pigs
In Vitro Techniques
Neurons drug effects
Action Potentials drug effects
Entorhinal Cortex physiology
Neurons physiology
Periodicity
Receptors, Muscarinic physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3077
- Volume :
- 90
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of neurophysiology
- Publication Type :
- Academic Journal
- Accession number :
- 12843303
- Full Text :
- https://doi.org/10.1152/jn.01063.2002