Journal article
Spatial and temporal control of intracellular free Ca2+ in chick sensory neurons
Pflügers Archiv, Vol.424(2), pp.183-191
07/1993
DOI: 10.1007/BF00374610
PMID: 8414905
Abstract
Digital imaging of fura-2 fluorescence and the voltage-clamp technique were combined to study cytoplasmic free Ca2+ concentration, [Ca]i, in neurons cultured from chick dorsal root ganglia. Depolarizing pulses raised [Ca]i to a new steady-state level which was achieved earlier in neurites than in the soma. The rise in [Ca]i during stimulated bursting or rhythmic activity was also faster in neurites. After stimulation [Ca]i recovered monoexponentially in the soma and biexponentially in neurites. Application of 50 mM KCl produced membrane depolarization and a concomitant increase of [Ca]i. During wash-out [Ca]i often declined to an intermediate steady-state level at which it stayed for several minutes. Thereafter the resting level of [Ca]i was quickly restored. [Ca]i recovery was delayed after treating the cell with 2 microM thapsigargin, an inhibitor of the Ca2+ pump of internal Ca2+ stores. Caffeine (10 mM) transiently increased [Ca]i. A second caffeine application produced smaller [Ca]i changes due to the prior depletion of Ca2+ stores, which could be replenished by brief exposure to KCl. Thapsigargin (2 microM) transiently increased [Ca]i both in the standard and Ca(2+)-free solution. [Ca]i transients due to caffeine and thapsigargin started in the cell interior, in contrast to [Ca]i changes evoked by membrane depolarization, which were noticed first at the cell edge. Caffeine and thapsigargin induced a transient inward current which persisted in the presence of 1 mM La3+ and in Ca(2+)-free solutions, but which was greatly diminished in Na(+)-free solutions. The effects of caffeine and thapsigargin were mutually exclusive both in the generation of [Ca]i transients and in the inward current induction.
Details
- Title: Subtitle
- Spatial and temporal control of intracellular free Ca2+ in chick sensory neurons
- Creators
- S L Mironov - Department of Neurophysiology, Max-Planck-Institute for Psychiatry, Planegg-Martinsried, GermanyYu M UsachevH D Lux
- Resource Type
- Journal article
- Publication Details
- Pflügers Archiv, Vol.424(2), pp.183-191
- Publisher
- Germany
- DOI
- 10.1007/BF00374610
- PMID
- 8414905
- ISSN
- 0031-6768
- eISSN
- 1432-2013
- Language
- English
- Date published
- 07/1993
- Academic Unit
- Iowa Neuroscience Institute; Anesthesia; Fraternal Order of Eagles Diabetes Research Center; Neuroscience and Pharmacology
- Record Identifier
- 9984040481102771
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