Journal article
ATP-gated current in dissociated rat nucleus solitarii neurons
Journal of neurophysiology, Vol.68(3), pp.778-785
09/1992
DOI: 10.1152/jn.1992.68.3.778
PMID: 1432047
Abstract
1. The excitatory response of extracellularly applied ATP was investigated in freshly dissociated rat nucleus tractus solitarii neurons under whole-cell configuration using the "concentration-clamp" technique. 2. At a holding potential of -70 mV, 100 microM ATP evoked inward current that was slowly desensitized in the continuous presence of ATP. The ATP-gated current increased in a concentration-dependent manner over the concentration range between 10 microM and 1 mM. The half-maximum concentration was 31 microM and the Hill coefficient was 1.2. 3. The potency of ATP analogues for the purinergic receptor was in the order of ATP = 2-methylthio-ATP much greater than ADP greater than alpha,beta-methylene ATP. Neither adenosine nor AMP evoked any responses. The order was consistent with a P2y receptor subtype. 4. The current-voltage relationship for the 100 microM ATP response showed a clear inward rectification at positive potentials beyond -50 mV. The reversal potential of the ATP-gated current was +13 mV. 5. The time constants of activation and inactivation of the ATP-gated current solution were dependent on the extracellular ATP concentration, and both kinetics became faster at higher ATP concentrations. 6. The ATP-gated current was also elicited in an external solution containing Ca2+ as a permeable cation. The inactivation kinetics in an external solution containing 75 mM Ca2+ were faster than those in an external solution with 150 mM Na+. 7. Calculated relative permeability ratios were PNa/PCs = 1.64 ([Na+]o = 30-150 mM), PCa/PCs = 2.17 ([Ca2+]o = 2 mM). Anions were not measurably permeable in this preparation.
Details
- Title: Subtitle
- ATP-gated current in dissociated rat nucleus solitarii neurons
- Creators
- Shinya Ueno - Department of Neurophysiology, Tohoku University School of Medicine, Sendai, JapanN HarataKazuhide InoueNorio Akaike
- Resource Type
- Journal article
- Publication Details
- Journal of neurophysiology, Vol.68(3), pp.778-785
- Publisher
- United States
- DOI
- 10.1152/jn.1992.68.3.778
- PMID
- 1432047
- ISSN
- 0022-3077
- eISSN
- 1522-1598
- Language
- English
- Date published
- 09/1992
- Academic Unit
- Molecular Physiology and Biophysics
- Record Identifier
- 9984025409202771
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