Spatial heterogeneity of caffeine- and inositol 1,4,5-trisphosphate-induced Ca2+ transients in isolated snail neurons.
Neuroscience
; 53(4): 943-7, 1993 Apr.
Article
em En
| MEDLINE
| ID: mdl-8506027
ABSTRACT
Inositol 1,4,5-trisphosphate- and caffeine-induced Ca2+ release was examined in neurons isolated from the mollusc Helix pomatia using Ca2+ indicator fura-2 and fluorescent digital-imaging microscopy technique. Extracellular application of caffeine caused a fast and pronounced augmentation of [Ca2+]i whose amplitude and kinetics differ in the centre of the cell and near its membrane. Mean values of caffeine-induced increase of [Ca2+]i were 0.97 +/- 0.11 microM at the periphery and 0.53 +/- 0.13 microM in the centre. The rates of rise and relaxation of caffeine-evoked [Ca2+]i transients were faster near the membrane. Pressure injection of inositol, 1,4,5-trisphosphate into the same neurons produced an abrupt and significant increase of [Ca2+]i in the centre (mean value of inositol 1,4,5-trisphosphate-induced elevation = 0.55 +/- 0.11 microM) while the response was smaller or even absent near the cellular membrane. Inositol 1,4,5-trisphosphate- and caffeine-induced Ca2+ transients did not affect each other. The data obtained indicate that in snail neurons these two calcium pools are not overlapping and at least some part of the caffeine-sensitive store is located close to the cellular membrane and that the inositol 1,4,5-trisphosphate-sensitive one is located in the centre of the cell.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cafeína
/
Cálcio
/
Caracois Helix
/
Inosina Trifosfato
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Neuroscience
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Ucrânia