Effects of various cations on the slow K+ conductance increases induced by carbachol, histamine and dopamine in Aplysia neurones.
Brain Res
; 259(1): 57-67, 1983 Jan 17.
Article
em En
| MEDLINE
| ID: mdl-6824936
ABSTRACT
A study was made of the effects of various cations other than K+ on three K+ conductance increases induced by carbachol, histamine and dopamine in an identified group of Aplysia neurones the 'A' neurones of the cerebral ganglion. The 3 responses were sensitive to alterations of both the extracellular and the intracellular concentrations of Na+ and Ca2+. In particular, they could be reduced markedly by (a) lowering [Na]0 (replacing NaCl by either Tris-HCl, glucosamine chloride, MgCl2 or sucrose); (b) increasing [Na]i (by intracellular injection of Na+, or by blockade of the Na+-K+ pump); (c) increasing the extracellular divalent cation concentration; or (d) increasing [Ca]i4. Some of the effects of Na+ and divalent cations appear to occur on reaction steps common to the three K+ responses, while others probably imply reaction steps specific to one of the systems, since they differ according to the agonist used. The sensitivity to Na+ and Ca2+ of slow inhibitory responses due entirely to an increase in K+ conductance must be taken into account in the interpretation of some slow hyperpolarizing responses previously assumed to involve changes in Na+ conductance.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Carbacol
/
Dopamina
/
Histamina
/
Cátions
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1983
Tipo de documento:
Article