Isoflurane inhibits calcium currents in neocortical neurons.
We used voltage-clamp techniques to assess the effects of isoflurane anaesthesia in slices of sensorimotor cortex of guinea pigs and neonatal rats. Isoflurane (0.5-4%) depressed inward Ca(2+)-currents evoked by depolarizing commands from -50 mV. With additional blockade of K(+)-currents by internal Cs+, an early component of the sustained inward currents was a high voltage-activated current whereas the delayed component was an unclamped Ca(2+)-current; this was consistent with a simple compartmental model. Isoflurane decreased the magnitude of the high voltage-activated current.
Puil
E
E
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Hutcheon
B
B
Reiner
P B
PB
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D002586:Cesium / Q000494:pharmacology; D005071:Evoked Potentials / Q000187:drug effects; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D026902:Potassium Channel Blockers; D051381:Rats
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D026902:Potassium Channel Blockers; D002586:Cesium; D007530:Isoflurane