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Cholinergic induction of oscillations in the hippocampal slice in the slow (0.5–2 Hz), theta (5–12 Hz), and gamma (35–70 Hz) bands
Author(s) -
Fellous JeanMarc,
Sejnowski Terrence J.
Publication year - 2000
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/(sici)1098-1063(2000)10:2<187::aid-hipo8>3.0.co;2-m
Subject(s) - carbachol , muscarinic acetylcholine receptor , hippocampal formation , chemistry , cholinergic , neuroscience , slice preparation , muscarinic agonist , endocrinology , electrophysiology , medicine , receptor , biology , biochemistry
Carbachol, a muscarinic receptor agonist, produced three distinct spontaneous oscillations in the CA3 region of rat hippocampal slices. Carbachol concentrations in the 4–13 μM range produced regular synchronized CA3 discharges at 0.5–2 Hz (carbachol‐delta). Higher concentrations (13–60 μM) produced short episodes of 5–10 Hz (carbachol‐theta) oscillations separated by nonsynchronous activity. Concentrations of carbachol ranging from 8–25 μM also produced irregular episodes of high‐frequency discharges (carbachol‐gamma, 35–70 Hz), in isolation or mixed with carbachol‐theta and carbachol‐delta. At carbachol concentrations sufficient to induce carbachol‐theta, low concentrations of APV reversibly transformed carbachol‐theta into carbachol‐delta. Higher concentrations of D,L‐2‐amino‐5‐phosphonopentanoic acid (APV) reversibly and completely blocked carbachol‐theta. A systematic study of the effects of carbachol shows that the frequency of spontaneous oscillations depended nonlinearly on the level of muscarinic activation. Field and intracellular recordings from CA1 and CA3 pyramidal cells and interneurons during carbachol‐induced rhythms revealed that the hippocampal circuitry preserved in the slice was capable of spontaneous activity over the range of frequencies observed in vivo and suggests that the presence of these rhythms could be under neuromodulatory control. Hippocampus 10:187–197, 2000 © 2000 Wiley‐Liss, Inc.