Hyperpolarisation-activated current in glomerular cells of the rat olfactory bulb.
Whole-cell patch-clamp recordings were carried out in visually identified periglomerular and external tufted cells of rat olfactory bulb. Most of the neurones showed a slowly developing hyperpolarisation-activated current with a threshold generally positive to resting potential and with a strongly voltage-dependent activation time constant. The current, identified as Ih, was sodium- and potassium-sensitive, suppressed by external caesium, and insensitive to barium. Under current-clamp conditions, perfusion with caesium induced a 10 mV hyperpolarisation and a marked reduction of the rate of low-frequency oscillations induced experimentally. It is concluded that most of the cells in the rat glomerular layer present a distinct h-current, which is tonically active at rest and which may contribute to the oscillatory behaviour of the bulbar network.
Cadetti
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Dipartimento di Biologia, Sezione di Fisiologia e Biofisica, Università di Ferrara, Via L. Borsari, 46, 44100 Ferrara, Italy.
Belluzzi
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D000818:Animals; D001464:Barium / Q000494:pharmacology; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology*; D002586:Cesium / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009415:Nerve Net / Q000187:drug effects / Q000378:metabolism*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism
D018756:GABA Antagonists; D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels; D002586:Cesium; D001464:Barium; D012964:Sodium; D011188:Potassium